Replacing fuel accumulator hoses

[Rich_NYS]

I searched & found a lot of accumulator threads, but not finding this.

When I replace the accumulator hoses:

-Should I jack the front or rear of the car? I'm thinking rear would give me more room, but I usually try to keep the heaviest part of the car down.

-Which connections on the accumulator should I leave alone? I'd like to disconnect the hard line from the connection that's on the unit & lower it down...sound reasonable?


Silly(?) question:

Are ramps better than a jack for working under the car? I've never used ramps....my dad had a repair shop with lifts where I used to live.

(If ramps are a necessity, any recommendations?)


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[Jimmyvonviggle]

I jacked up the back end and put ramps under both rear tires. To prevent the car from rolling forward due to the incline I placed another set of ramps butted up against the front tires. I still left two jack stands toward the back of the car, just in case the ramps failed (paranoid?). This gave me enough clearance to reach that accumulator spot.

[DMCMW Dave]

I searched & found a lot of accumulator threads, but not finding this.

When I replace the accumulator hoses:

-Should I jack the front or rear of the car? I'm thinking rear would give me more room, but I usually try to keep the heaviest part of the car down.

-Which connections on the accumulator should I leave alone? I'd like to disconnect the hard line from the connection that's on the unit & lower it down...sound reasonable?


Silly(?) question:

Are ramps better than a jack for working under the car? I've never used ramps....my dad had a repair shop with lifts where I used to live.



Personally I've never had success getting a car on ramps. They either walk across the floor or I'm scared that I'm going to drive off the back. Hard to use in a garage too. As for clearance lifting the back is probably better but it's close to centered in the car. Time to buy a lift. :hihi2:

NEVER attempt to take off any of the body-side fittings. You need to remove the one hard line at the accumulator, then the small hose facing the back of the car. The other one is long enough that you can pull the accumulator out of the frame still attached and work on it outside.

[Rich]

I searched & found a lot of accumulator threads, but not finding this.

Some of your questions are addressed in this thread, more aimed at the fuel filter, but the accumulator sneaks in there, too:

http://dmctalk.org/showthread.php?8872

Rhino Ramps are pretty good - along with a low-rise creeper - for jobs like this. You may still need a mirror to see everything up there since these ramps have a 7inch lift. See if you can find taller ones?

Other threads tell about jackstands.

A real lift is ideal, of course.

[jwrayth]

I used ramps on the rear whilst replacing the hoses on my accumulator. Doesn't give you a whole lot of clearance to work in, but it is enough. Dave is right about the ramps being a bit of a pain though; took a bit of practise to get the DeLorean up the ramps nicely without the ramps shifting!

[Bitsyncmaster]

I use both ramps and jacks to do an accumulator. Back the car onto ramps and then jack the front with two floor jacks. I then use 6"/6" wood blocks under the frame near where the jacks are located.

[Jonathan]

Rich,

I use both ramps and jack stands, but never drive my car up on the ramps. I tend to jack the car high enough in the air that I can slide the ramps under the wheels and lower it down on to them. Not exactly the intended purpose, but I often do both sets just for safety/redundancy. The jacks will likely get you more space to work than ramps as when you ease the car on to the ramps the suspension compresses and it lowers a bit.

I had someone else do my accumulator years ago, but recently I did an ATF change and dipstick seal and pan seal replacement. Not a lot of room to work as my nose was pretty close to the bottom of the car. Lying on a creeper helps get you in and out from underneath. And stay away from concrete cinder blocks for putting under the car... they are not strong enough nor consistently manufactured to risk your life on.

I'll also keep the jack in it's place when I work if it isn't in the way. Similar with ramps/stands. If you need to work on brakes then you can't use ramps of course when the wheels are off. Whatever you choose, pick a back-up to use with it at the same time. The probability of one giving out might be slim, but both of your supports simultaneously failing is quite rare. And a cell phone in your pocket won't help I'm afraid even though some might think it will.

[David T]

Rich,

I use both ramps and jack stands, but never drive my car up on the ramps. I tend to jack the car high enough in the air that I can slide the ramps under the wheels and lower it down on to them. Not exactly the intended purpose, but I often do both sets just for safety/redundancy. The jacks will likely get you more space to work than ramps as when you ease the car on to the ramps the suspension compresses and it lowers a bit.

I had someone else do my accumulator years ago, but recently I did an ATF change and dipstick seal and pan seal replacement. Not a lot of room to work as my nose was pretty close to the bottom of the car. Lying on a creeper helps get you in and out from underneath. And stay away from concrete cinder blocks for putting under the car... they are not strong enough nor consistently manufactured to risk your life on.

I'll also keep the jack in it's place when I work if it isn't in the way. Similar with ramps/stands. If you need to work on brakes then you can't use ramps of course when the wheels are off. Whatever you choose, pick a back-up to use with it at the same time. The probability of one giving out might be slim, but both of your supports simultaneously failing is quite rare. And a cell phone in your pocket won't help I'm afraid even though some might think it will.

There are many reasons to NOT use ramps. You can't get high enough to use a creeper. They can fall over sideways. You can drive off them. If the floor is not flat they can be unstable. The cheap ones can collapse. If you do not have a lift get 4 good jackstands (they are not expensive) and a good floor jack. You can get all of that for under $300 and be safe. If you are going to be doing your own work and saving some money you have to invest some money into the tools necessary to do your own work (and do it safely).

[NightFlyer]

IMHO, it's much nice to work on the accumulator with the whole car up in the air. All you need is 4 jack stands set at (close to) equal height - 2 for the front and 2 for the rear. Doesn't take much more time/effort to put the whole car up in the air vs just the front or back and makes working on things underneath so much nicer/easier.

As far as jacking up the car, I prefer to jack on the frame as opposed to the factory suggested body tub jack points (jacking on fiberglass really scares me). Just remember to use a small block of wood topped by something soft (old piece of carpet, folded shop rag, junky towel, etc) between the jack / jack-stands and the frame, as you don't want to crack any of the epoxy.

And like Dave S said, remove the hard line connection at the accumulator, then remove the rear clamped hose, then drop the accumulator and you should be able to remove the final hose from the accumulator. Two wrenches for the two forward lines - one on the fitting and one on the nut attached to the accumulator.

As your car doesn't appear to have a hot start problem, you really don't need to change out the accumulator itself. Same procedure as swapping out the hoses between the pump and hardlines at the tank - razor blade them off the fittings, and clamp your replacement hoses to the fittings.

Have fun and best luck!

[Rich_NYS]

THANKS EVERYBODY!

Great instruction & excellent info....much appreciated. I think I'll get two more jackstands, the idea of ramps makes me uneasy and I see others aren't fans of 'em either so I guess I'm not alone. I like the sounds of more clearance; I do have a creeper, but I prefer a big piece of carboard to get more workspace and I can slide around easier.

In my prime I was a competition bench-presser, so my disaster plan is to heave the car into the air if a jackstand fails....anybody ever need to do that? :strongman:

[Bill6298]

I would agree with those that say four jack stands are best for this job. I use Esco flat top jack stands that include flat rubber pads. No need for wood or any other material on top of the stands. I feel really safe with them. The cons are: outrageous price, they are huge - width and height (could be a benefit), and made in china. I wouldn't pay anywhere near retail but there are deals to be found either new or used. Last I checked jbtoolsales.com has the best new price @ $60 each (free shipping). I've seen them (or the non-Chinese brand) for less on craigslist.

This link will show the size relative to other stands. http://revlimiter.net/blog/2010/07/mega-jack-stand-review-1/

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[DMCMW Dave]

I do have a creeper, but I prefer a big piece of carboard to get more workspace and I can slide around easier.

:

Interesting comment. I have a couple of creepers from way back (pre-lift ownership) and they both look brand new (Christmas gifts etc.) I always preferred sheets of cardboard for the same reason.

[NightFlyer]

All of my jack stands are old school made in USA that I pick up for roughly $5/ea at car show swap meets.

Ditto on the cardboard - it's the only thing I ever use when working under a car :smile:

[Jimmyvonviggle]

Also cardboard is good for absorbing the oil drips.

[Bitsyncmaster]

I've never owned a creeper. Just a place for your tools to get lost under. Cardboard is the best but I also have some old carpet pieces and blankets I use.

[jawn101]

We literally just did one of these hoses on my car today. Jacked up the ass of the car as high as it would go. Our skinniest guy did the actual work but he had the old hose removed and the new one clamped on and ready to go in about 15 minutes with nothing more than a pair of nippers, a razor blade and a ratchet to secure the new clamps.

[Rich_NYS]

We literally just did one of these hoses on my car today. Jacked up the ass of the car as high as it would go. Our skinniest guy did the actual work but he had the old hose removed and the new one clamped on and ready to go in about 15 minutes with nothing more than a pair of nippers, a razor blade and a ratchet to secure the new clamps.

Cool...hopefully mine will go just as smooth!

[DMC5180]

I like those Rubber pads on the jack stands. Wish mine had those. FWIW: Anytime I'm up on all four stands, I maximize the lifted space by going full Height on the stands. 16 Inches in my case makes a huge difference in moving around under the car. I also use Large sheets of Cardboard ( saved from furniture packaging boxes ) not so much for sliding around but rather being an instantly clean surface to move around on.

[Jacko]

THANKS EVERYBODY

In my prime I was a competition bench-presser, so my disaster plan is to heave the car into the air if a jackstand fails....anybody ever need to do that? :strongman:

No, I've never had to lift the car with my bare hands. If it came to that I'd
probably still be under there ... you must have been a heckuva bench presser!:wow:

[kings1527]

I put this question on the fuel/sender thread but wanted some thoughts from this thread, too. Sorry for the redundancy.

I'm going to be replacing my fuel accumulator and I'm debating whether or not to replacing the flexible line that's above the hardline going into the fuel accumulator (on the two-connection side). To my knowledge, the replacement line that's available is flexible whereas the OEM is on the more rigid side. A part of me wants to keep that OEM hose in there and reduce the chance of the same kink developing that Jon had with his fuel pump issue. Thoughts?

[jawn101]

Personally my opinion is to replace it. The kinked hose was not the new rubber-only style that is currently available. The kinked one was not OEM but was OEM-style at least. But my experiences are not indicative of what anyone else should expect. I am just a big fan of not taking any risks with gasoline.

[NightFlyer]

If the black composite outer sheath is sticky to the touch and flaking off, exposing the braided fabric mid-layer, then it's a stock/OEM hose. If not, then it's probably some kind of aftermarket replacement hose.

If the hose is stock/OEM and hasn't been stressed at all, then it should be fine. If it has been through a couple accumulator changes already though, then it's probably a good idea to change it out with a new piece of Gates fuel injection (high pressure) hose.

[Rich_NYS]

IMHO, it's much nice to work on the accumulator with the whole car up in the air. All you need is 4 jack stands set at (close to) equal height - 2 for the front and 2 for the rear. Doesn't take much more time/effort to put the whole car up in the air vs just the front or back and makes working on things underneath so much nicer/easier.

As simple a suggestion as it seems, I hadn't realized how much of a different it would make...much better! :thumbup:



I'm into something a bit odd with the hoses: the single hose connection on the rear of the accumulator (R. side of pic) appears to be 5/16 squeezed down on the accumulator, or 1/4 forced over the barb (in the top of the cubby.) In either case, the fitting on the accumulator is smaller than the barb fitting at the top of the cubby hole. There was no clamp at the top and I pulled it off without cutting it. The accumulator side was clamped.

Any thoughts on what size to use?

Also, what type of hose do I need? I haven't yet learned much about the accumulator, but I understand it maintains pressure in the system. I read some of the other threads & it appears this hose is low pressure so I'm thinking I should use regular fuel line: either 1/4 or 5/16.

Thanks!

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[Bill6298]

Any thoughts on what size to use?

25106

I have the complete kit with hoses/clamps from DMCMW in my garage. I can measure for you after work today if you don't get an answer sooner.

[Rich_NYS]

I have the complete kit with hoses/clamps from DMCMW in my garage. I can measure for you after work today if you don't get an answer sooner.


Thanks man...

[NightFlyer]

The fuel accumulator serves two purposes: 1) to maintain pressure on the fuel system during engine cool downs; and 2) to even out the flow of fuel from the pump and reduce fuel flow noise.

Inside, it's essentially a spring loaded diaphragm, and looks like this:

http://vnc.thewpp.ca/stuff/bentley/ep0niks.ctech.ca/vw/eva2/FU01/i21726.gif

The rear hose merely directs fuel that leaks around the internal diaphragm into the return feed line. If the accumulator is functioning perfectly, it should never expel fuel from that hose. As the springs rarely suffer a complete failure, the fuel that does manage to leak around the diaphragm isn't under very much pressure.

Use your Gate's fuel injection hose (what ever size fits best) and a couple clamps, knowing that this connection isn't super critical, but you still want to get it as snug as possible.

Have fun and best of luck!

[Rich_NYS]

Thanks!

[Bill6298]

My kit from DMCMW has a different size hose for the feed and return. I didn't have a ruler handy that will measure in 16ths so I used the millimeter side. FWIW, the clamps were also different sizes and part numbers. I also chose the "new" accumulator that is smaller than OEM although I understand the original size is available as "new" in limited production runs. Not sure if this makes a difference with the hoses.

The feed hose is larger with an inner diameter of ~5/16" (measured 7mm). The outside says "7, 5X3". Someone more knowledgable might be able to confirm that means 7mm ID.

The return has a smaller ID and clearly states "1/4 (6.35mm)" on the outside.

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Looks like 106997 is $11.70 and 106999 is $6.94 at DMC plus shipping. Clamps - SP10345 and SP10348 are $1.65.

[Rich_NYS]

The feed hose is larger with an inner diameter of ~5/16" (measured 7mm). The outside says "7, 5X3". Someone more knowledgable might be able to confirm that means 7mm ID.

The return has a smaller ID and clearly states "1/4 (6.35mm)" on the outside.



Thanks Bill,

1/4" is what I decided on and it fits well.

For the feed, I expected it to be 5/16 based on what I see in the parts manual (same hose used at the pump,) but it doesn't seem to fit so well on my car....not sure what to think about that yet.

Thanks for the confirmation on the sizes....very helpful!

[Bill6298]

Thanks Bill,

1/4" is what I decided on and it fits well.

For the feed, I expected it to be 5/16 based on what I see in the parts manual (same hose used at the pump,) but it doesn't seem to fit so well on my car....not sure what to think about that yet.

Thanks for the confirmation on the sizes....very helpful!

It might really need 7mm ID and that's the problem with using 5/16 which is 7.9375mm. I couldn't say if it matters or not. I think that's the cheaper of two hoses if you're already paying shipping for other stuff at DMCMW. Would probably double the cost to ship it unless they'll put it in a USPS envelope or something.

I haven't looked at the parts manual but if it calls for 5/16" at the accumulator, that could be for the original size accumulator. Just a guess.

[NightFlyer]

As long as the ID of the hose you're using isn't smaller than the ID of the steel hardlines, then it really shouldn't matter what size hose you use, as you won't be bottle-necking the system at all. Go with whatever fits on the barbs best and you feel comfortable with.

[Rich_NYS]

I haven't looked at the parts manual but if it calls for 5/16" at the accumulator, that could be for the original size accumulator. Just a guess.

I didn't see 5/16 in the manual, but the part# for both hoses is the same, and on my car the hoses on the pump end are 5/16". I think something is different about mine, possibly the barbs were changed...I don't think they're the same as what I found on the tank end.

I need more clamps....gonna have to finish tomorrow.

Thanks again for the info!

[Rich_NYS]

Definitely wasn't the 5/16 I have on the tank end. I tried 5/16, was able to completely close the clamp, and still was able to rotate the hose on the barb.

1/4 fits good; I could put it on & take it off, and it clamped nicely. Most importantly....no leaks! :rock_on:

Here's a pic of the inner portion of the hose I took off alongside a section of 1/4 and 5/16.

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[kings1527]

Definitely wasn't the 5/16 I have on the tank end. I tried 5/16, was able to completely close the clamp, and still was able to rotate the hose on the barb.

1/4 fits good; I could put it on & take it off, and it clamped nicely. Most importantly....no leaks! :rock_on:

Here's a pic of the inner portion of the hose I took off alongside a section of 1/4 and 5/16.

25135

Nice job, Rich!

I was right behind you on this. I ended up ordering my accumulator from a different source because I wanted the full size version. I fully support and believe that the smaller version will work just fine (maybe less time on holding rest pressure) but my biggest issue is keeping things as original as possible on my car. But that's my own personal problem.

Anyways, I completed the fuel accumulator replacement and I have to say that it's not as bad as some make it out to be. Now, that might be because I'm 6' and 160# with skinny arms and small hands, but it wasn't that bad for me. I did it with a high-lift jack, stands, long handled 17mm and 19mm, stubby 17mm and 19mm, and a 1/4" drive socket with a 10mm and super long extension. I'll detail everything in my blog when I write it up. I have to get back to that.

I decided to go ahead and replace the main feed line going to the accumulator. I used 1/4" ID line and everything fit well. One problem that I found was that the replacement hose that I got was a tad too short and it actually kinked slightly when making the turn towards the front of the car right off the nipple. I decided to go with it and then put everything back together and fired it up. Everything was great and rest pressure problem solved, too.

But then I waited a bit until everything was completely cold and rest pressure, I'm sure, was gone. Eight hours or so. I went to start it up and now I had a weird cold start problem. WTF? It took a solid five seconds to get it to go. So I pulled my cold start valve, put it in a jar, and turned it over and luckily there was fuel in it. :) but at the same time :confused0:

So I go back to thinking that maybe that kink in the new line is causing a slight delivery problem during a cold start. And mind you, after I installed my new accumulator I ran the car HARD (redlining a few times) just to be sure all was well. No problems at all. I swear, the PRV truly is awesome. I picked up a new fuel line, this one was about 4" longer than the other and pulled the accumulator AGAIN (getting real awesome very quickly at that) and this time things were perfect with the line. No kinks or anything like that at all.

So I go to start it again. Same thing. Real hard cold start, taking maybe five seconds or so worth of cranking. My car never did that beforehand. Maybe a second or two when cold. But I know my CSV is working.

So then I go back to, how does it go, RTFM when it comes to starting your vehicle and it states to depress the accelerator about 1/4 of the way to bypass the idle speed microswitch and BOOM it fired up in about 1/2 second. Interesting. But I really don't know why a bad accumulator wasn't causing cold start issues without depressing the accelerator. Maybe now that the diaphragm in the accumulator is good, it takes a certain amount of force from the fuel pump to push back the diaphragm on the spring and pressurize the rest of the system, whereas before fuel was always leaking past the diaphragm and the fuel pump and rest of the fuel system didn't know the difference. As a result, fuel traveled to the injectors faster since it didn't have to battle against a good diaphragm and spring? I really don't know.

Any ideas on that?

But anyways, an 18" section of 1/4" ID fuel injection hose (available for about $5 at Pep Boys or wherever) will take care of that one line. All and all, the fuel accumulator job really isn't that bad (depending on your physique). There are a couple of great writeups on it, including one that DMCH did. The fuel filter sucked way harder for me.

[jawn101]

So then I go back to, how does it go, RTFM when it comes to starting your vehicle and it states to depress the accelerator about 1/4 of the way to bypass the idle speed microswitch and BOOM it fired up in about 1/2 second. Interesting. But I really don't know why a bad accumulator wasn't causing cold start issues without depressing the accelerator. Maybe now that the diaphragm in the accumulator is good, it takes a certain amount of force from the fuel pump to push back the diaphragm on the spring and pressurize the rest of the system, whereas before fuel was always leaking past the diaphragm and the fuel pump and rest of the fuel system didn't know the difference. As a result, fuel traveled to the injectors faster since it didn't have to battle against a good diaphragm and spring? I really don't know.

Any ideas on that?



That's very weird. The only thing that depressing the pedal does is open the throttle body. You should try unplugging the idle microswitch and see if the cold start issue is gone without the pedal depressed.

[kings1527]

That's very weird. The only thing that depressing the pedal does is open the throttle body. You should try unplugging the idle microswitch and see if the cold start issue is gone without the pedal depressed.

My thought was that it deactivates the idle speed system and therefore keeps the ISM closed, which makes for a richer environment (once fuel from the CSV is introduced during a cold start) and easier to start. Not sure if I'm right on that.

[Bitsyncmaster]

Pressing the gas pedal during start does two things. Open the throttle plates and turns off the vacuum advance to the ignition distributor. I don't think you get much vacuum until the engine fires (may be wrong) the only change would be more throttle. The idle ECU (stock unit and mine) will open the idle motor to a set amount dependent on the engine temp sender feeding the idle ECU. A cold engine opens it more than a hot engine. Now the stock idle ECU will start to open the idle motor as soon as the key is turned to on even when your not cranking the engine. So depending on how long you wait to start cranking the engine will change the "throttle" opening amount. My idle ECU will not do that (it stays put until you crank the engine).

I have a habit with all my engine starts (daily drivers and the D) to crank the engine for a second or two with not "gas" and then if you don't get it to fire, give it some "gas". With my D, I wait till the fuel pump stops it initial prime.

So one variable to starting our engines is how long the driver waits to start cranking the engine after the key is turned to on. If you need to use "gas", try waiting a few seconds longer to see that helps.

[kings1527]

I have no idea why I'd be having this problem after putting in a fuel accumulator. I started it up this morning to come to work and it took about a solid five seconds with the accelerator slightly depressed. Before, it took about half that time, easily. And no accelerator. I'll try starting it in a bit without the accelerator and see how that goes.

There has to be something about the resistance a new accumulator provides. I took out my repro dash that same day and installed an original dash that's in great shape, but that was the only other thing. Can't imagine that had anything to do with it.

I also have a slight thumping that happens as the fuel system is running. It seems like it comes from somewhere between the pump and the accumulator. Kind of tough to place. I seem to remember that being normal from another thread.

And I'm not convinced that my starting issue isn't normal. Five seconds or so doesn't seem like a long time. It's just different from what I had before.

I welcome thoughts.

[kings1527]

And yes Dave, I completely wait for your rpm relay to prime before starting.

[Bitsyncmaster]

How fast is that thumping? My accumulator will thump as the rest pressure declines but that takes many hours after engine shutdown.

[kings1527]

How fast is that thumping? My accumulator will thump as the rest pressure declines but that takes many hours after engine shutdown.

It's as it's running and maybe once every 10 seconds or so.

[DMCMW Dave]

Pressing the gas pedal during start does two things. Open the throttle plates and turns off the vacuum advance to the ignition distributor. .

Vacuum advance is off when the engine is cold and when the throttle is closed. Opening the throttle on a hot engine will apply vacuum to the distributor, but with a delay since there is no vacuum when the engine isn't running, and with the throttle open there isn't much either.

[kings1527]

Vacuum advance is off when the engine is cold and when the throttle is closed. Opening the throttle on a hot engine will apply vacuum to the distributor, but with a delay since there is no vacuum when the engine isn't running, and with the throttle open there isn't much either.

Dave,

Does that thumping sound familiar to you?

Does it make sense that the car is a bit harder to start when completely cold just after installing a brand new fuel accumulator?

I have no idea what would've caused a significant change simply after installing an accumulator.

[Bitsyncmaster]

It's as it's running and maybe once every 10 seconds or so.

It must not be the same accumulator thump. The accumulator thump is the spring inside a the accumulator as it moves.

Have you done a rest pressure time check?

[kings1527]

It must not be the same accumulator thump. The accumulator thump is the spring inside a the accumulator as it moves.

Have you done a rest pressure time check?

It's tough for me to pinpoint exactly where it's coming from. It could be from the accumulator.

I've done a plate test to check the rest pressure and I'm good for well over an hour. I haven't checked past that. Before, I'd be back down to zero pressure on the plate easily by 25 minutes.

[kings1527]

Here's a video that I did just now. I have the DMCH fuel pump/sender combo, new fuel accumulator, and Dave's self-priming RPM relay.

I timed it around 4.5 to 5 seconds. If you listen closely in the background after it starts, you can hear that thumping that I was talking about.

Would you guys consider this normal or not as far as start up goes? Anyone elses car doing the same during a complete cold start up without any fuel system pressure? Anyone else have a thump like that?


http://www.youtube.com/watch?v=ZtaxNISrCWw&feature=youtu.be


Mods: if I'm spinning this thread out of control, we can start a new one. Thanks!

[NightFlyer]

What's a hot start like?

Ever since installing the check valve, I honestly don't notice much of a difference between a hot and a cold start, which is usually within a second or two of initiating the starter. Definitely don't have the audible thump that you're experiencing - are you able to localize where that thump is coming from?

[kings1527]

What's a hot start like?

Ever since installing the check valve, I honestly don't notice much of a difference between a hot and a cold start, which is usually within a second or two of initiating the starter. Definitely don't have the audible thump that you're experiencing - are you able to localize where that thump is coming from?

Hot starts are great, now. Since my accumulator replacement, the car will start easily within 1/2 second or so on a hot start. As far as the thump goes, I'll put it on a jack again and really pinpoint exactly where the thump is coming from.

So here's a video I just did since the last video. The car sat for about 12 hours so I can only assume zero rest pressure on top of a completely cold engine, but this time I'm depressing the accelerator about 1/4 of the way just like it states to do in the operator's manual. You can see how quickly the car starts and hopefully this wasn't just an anomaly.


http://www.youtube.com/watch?v=RAmOtDka6iU&feature=youtu.be

I'm going to call this good, except for the thumping which I'll figure out today.

[refugeefromcalif]

I'm going to add my issues.
I had a Hot start problem that turned out to be a Small part accumulator, and Big part check valve of the new fuel pump combo unit.
I replaced the accumulator and added an external check valve. Hot start problem fixed.
After a few months I started having a Cold start issue. (Winter hit).
My *Fix* was cycling the key 6-8 times in cold weather. Car would start within 2 seconds.
After reading about Alex's issue, I tried depressing the gas pedal as I try to start it the first time. It's worked like a Dream the past few mornings.? (Yesterday it was 34 deg., today it was 32).
When I don't depress the pedal, I have to go through the cycle method or, hit the gas pedal.?

George

[kings1527]

I'm going to add my issues.
I had a Hot start problem that turned out to be a Small part accumulator, and Big part check valve of the new fuel pump combo unit.
I replaced the accumulator and added an external check valve. Hot start problem fixed.
After a few months I started having a Cold start issue. (Winter hit).
My *Fix* was cycling the key 6-8 times in cold weather. Car would start within 2 seconds.
After reading about Alex's issue, I tried depressing the gas pedal as I try to start it the first time. It's worked like a Dream the past few mornings.? (Yesterday it was 34 deg., today it was 32).
When I don't depress the pedal, I have to go through the cycle method or, hit the gas pedal.?

George

So I'm not crazy. Thanks for posting this, George.

I'm still trying to troubleshoot this in my mind and the best I can come up with is this: if you had a bad accumulator, either the diaphragm was perforated and/or the spring wasn't working. That created a pretty static environment for fuel. When the car is off, the diaphragm should be pushed forward, towards the fuel connections. But since the accumulator isn't working correctly, fuel sort of 'bypasses' the accumulator's diaphragm and spring. The more static (and less movement of fuel within the accumulator), the faster pressure is built up in the system and the faster fuel is delivered to the injectors. Hence, a fast start up.

But if you have a good accumulator with a good diaphragm/spring, then the fuel situation becomes dynamic when you go to start the car. As you go to start it, the diaphragm and spring both compress and create more room for the fuel to travel, therefore taking more time for fuel pressure to build and to travel to the injectors. That'd be a slower start up.

Exactly where depressing the accelerator fits into all this, I'm not so sure. In fact, my whole theory may be a bunch of horsepucky and I'd be fine with that. But that's the best that I can come up with right now and the ONLY difference during this whole adventure has been a bad versus a good fuel accumulator. It's gotta be something with that.

[Jonathan]

I have no idea why I'd be having this problem after putting in a fuel accumulator. I started it up this morning to come to work and it took about a solid five seconds with the accelerator slightly depressed. Before, it took about half that time, easily. And no accelerator. I'll try starting it in a bit without the accelerator and see how that goes.

There has to be something about the resistance a new accumulator provides. I took out my repro dash that same day and installed an original dash that's in great shape, but that was the only other thing. Can't imagine that had anything to do with it.

I also have a slight thumping that happens as the fuel system is running. It seems like it comes from somewhere between the pump and the accumulator. Kind of tough to place. I seem to remember that being normal from another thread.

And I'm not convinced that my starting issue isn't normal. Five seconds or so doesn't seem like a long time. It's just different from what I had before.

I welcome thoughts.


Dave,

Does that thumping sound familiar to you?

Does it make sense that the car is a bit harder to start when completely cold just after installing a brand new fuel accumulator?

I have no idea what would've caused a significant change simply after installing an accumulator.


Here's a video that I did just now. I have the DMCH fuel pump/sender combo, new fuel accumulator, and Dave's self-priming RPM relay.

I timed it around 4.5 to 5 seconds. If you listen closely in the background after it starts, you can hear that thumping that I was talking about.

Would you guys consider this normal or not as far as start up goes? Anyone elses car doing the same during a complete cold start up without any fuel system pressure? Anyone else have a thump like that?


http://www.youtube.com/watch?v=ZtaxNISrCWw&feature=youtu.be

Alex,

Can I ask you if the flickering of your battery light when you start the car in your videos is normal? Is this just the camera lighting/frame rate doing this or does it really do this in person? I do not recall seeing my car or others have a flickering battery light like yours. It may be related to the RPM relay you are using perhaps, but I have not used one of those so can't say myself. Just thought I would mention it as it didn't seem "normal" to me and could be related to your issues.

[refugeefromcalif]

Alex,

Can I ask you if the flickering of your battery light when you start the car in your videos is normal? Is this just the camera lighting/frame rate doing this or does it really do this in person? I do not recall seeing my car or others have a flickering battery light like yours. It may be related to the RPM relay you are using perhaps, but I have not used one of those so can't say myself. Just thought I would mention it as it didn't seem "normal" to me and could be related to your issues.

It's because of his DMCH 140 amp alternator. Mine does it also.

I'm looking for a past Dave S. commment about it.

George

[Jonathan]

It's because of his DMCH 140 amp alternator. Mine does it also.

I'm looking for a past Dave S. commment about it.

George

Thanks George. I don't have the 140 Amp alternator either and didn't recognize that as a sign. Glad you pointed it out. Cheers.