Fuel pump awesomeness! (Sarcasm)

[OverlandMan]

http://dmctx.blogspot.com/2014/09/fuel-pump-surprise.html

Forgive me but I didn't want to type the same story out twice thus the link. Figured I'd share and welcome any comments or thoughts. Seems fairly straight forward in replacing the rubber components except for the return line in the tank. I haven't looked at a diagram yet but where does that connect? Hopefully it's not a booger to get out.

At this point I'm thinking I should be concerned with rubber debris/breakdown inside the tank. Is that concern confirmed with the fellow DIY owners? I'm open to suggestions.

[DMC5180]

The in-tank rubber return line clips to the inside edge of the Baffle cup so that it dumps the fuel inside the cup. The other end connects to the Metal tube that passes through the FP boot.

[Henrik]

Jeff,
Everything comes apart and out of the tank just fine. That's not an issue.

It is extermely important that you clean out the tank though. I can't remember what I used in terms of liquid but I do remember putting a flashlight in there and then wiping it meticuously with a rag. You will need a longer handle, like a ruler or whatever to shove the rag all the way to the back of the tank. It's a good idea to use a white rag, like an old pillow case to make sure you get rid of the little black, tarry chunks of rubber remnants. They're easy to miss since the tank is black color. For inspection purposes I also shot a video with my phone of the inside of the tank. You kinda have to move it around in unison with the flash light, but it worked great.

My MAIN GRIPE with the Delorean is the stock fuel pump arrangement. As you can see in this link I had major problems sealing off the nipple for the return line going through the rubber boot three years ago.
http://dmctalk.org/showthread.php?2084-Fuel-tank-overflow-issue
Actually, I never found a way to seal it so instead I just made sure I never filled the tank 100%. To add to the problem, my fuel sender was messed up so I never knew exactly how much was in there - which resulted in overflows at the gas stations numerous times. A river of gasoline tends to make other people, including the owner, very nervous.

The rubber boot in the picture of the link was brand new when I took the photo. Well, within a year or two when I pulled it out to inspect it was as gooey as yours is.

I'm telling ya, ditch the darrn thing and buy DMCH's all-in-one unit :)

[David T]

Acetone is used to clean the tank. You must use caution and personal safety equipment since it is very flammable and toxic. I agree the original set-up is kind of a mess but with good, fresh parts properly installed, it works. The new unit looks very nice and easy to install but it is getting mixed reviews. Some have had problems with the fuel gauge and some have had hard hot restart problems.

[OverlandMan]

Jeff,
Everything comes apart and out of the tank just fine. That's not an issue.

It is extermely important that you clean out the tank though. I can't remember what I used in terms of liquid but I do remember putting a flashlight in there and then wiping it meticuously with a rag. You will need a longer handle, like a ruler or whatever to shove the rag all the way to the back of the tank. It's a good idea to use a white rag, like an old pillow case to make sure you get rid of the little black, tarry chunks of rubber remnants. They're easy to miss since the tank is black color. For inspection purposes I also shot a video with my phone of the inside of the tank. You kinda have to move it around in unison with the flash light, but it worked great.

My MAIN GRIPE with the Delorean is the stock fuel pump arrangement. As you can see in this link I had major problems sealing off the nipple for the return line going through the rubber boot three years ago.
http://dmctalk.org/showthread.php?2084-Fuel-tank-overflow-issue
Actually, I never found a way to seal it so instead I just made sure I never filled the tank 100%. To add to the problem, my fuel sender was messed up so I never knew exactly how much was in there - which resulted in overflows at the gas stations numerous times. A river of gasoline tends to make other people, including the owner, very nervous.

The rubber boot in the picture of the link was brand new when I took the photo. Well, within a year or two when I pulled it out to inspect it was as gooey as yours is.

I'm telling ya, ditch the darrn thing and buy DMCH's all-in-one unit :)

Hey Henrik, thanks for the insight. So did the 45 cent clip not fix your leaky overfill issue? That's discouraging about your rubber boot turning to goo that quickly. It seems like rubber products are not what they were years ago and contain more synthetics, which makes them more brittle and prone to temperature change apparently as well as turning to goo when around gasoline and I'm sure other chemicals.

I already ordered a replacement boot along with some new hoses and such. They should be here today and I plan to work on this tomorrow. I'll try to make this work for a year or two but inspect it down the road like you did to see if mine new replacement degrades that quickly.

Again - appreciate the tips.

[OverlandMan]

Acetone is used to clean the tank. You must use caution and personal safety equipment since it is very flammable and toxic. I agree the original set-up is kind of a mess but with good, fresh parts properly installed, it works. The new unit looks very nice and easy to install but it is getting mixed reviews. Some have had problems with the fuel gauge and some have had hard hot restart problems.

Thanks David. I'll try cleaning with acetone using caution. I've also seen the mixed reviews on the new all-in-one unit. Those combined with the $400+ price tag led me back to fixing the stock setup instead. My sender unit and pump both work fine. It was just this perished rubber boot that surprised me last weekend.

[Henrik]

Hey Henrik, thanks for the insight. So did the 45 cent clip not fix your leaky overfill issue? That's discouraging about your rubber boot turning to goo that quickly. It seems like rubber products are not what they were years ago and contain more synthetics, which makes them more brittle and prone to temperature change apparently as well as turning to goo when around gasoline and I'm sure other chemicals.

I already ordered a replacement boot along with some new hoses and such. They should be here today and I plan to work on this tomorrow. I'll try to make this work for a year or two but inspect it down the road like you did to see if mine new replacement degrades that quickly.

Again - appreciate the tips.

Hi Jeff,
No, I never was able to make the 45 cent clip work. If you look at the picture the rubber nipple was too short for it to go on it, and - to boot - the ID of the nipple thru-hole was way larger than the OD of the pipe. So no matter how much I fiddled with that clip, I never was able to make it clamp on let alone make any kind of seal.

As far as the issues with the DMCH $400+ unit. The gas gauge is very accurate as far as I can tell, and the re-start issue (the check valve to prevent the gas line from emptying itself back into the tank when not running was faulty) has been fixed. My unit had a brass check-valve already crimped in when I received my unit.

[David T]

Thanks David. I'll try cleaning with acetone using caution. I've also seen the mixed reviews on the new all-in-one unit. Those combined with the $400+ price tag led me back to fixing the stock setup instead. My sender unit and pump both work fine. It was just this perished rubber boot that surprised me last weekend.

Not only is the rubber not made like it used to be, the fuel is a lot more corrosive on all of the components too. On top of all of that nothing seems to last anymore. If you can't get the parts for the original set-up (and eventually you won't) you will have no choice but to go for the new one.

[OverlandMan]

Not only is the rubber not made like it used to be, the fuel is a lot more corrosive on all of the components too. On top of all of that nothing seems to last anymore. If you can't get the parts for the original set-up (and eventually you won't) you will have no choice but to go for the new one.

But probably until then I'll continue with the OEM-type solution.

[DL4567]

The modern DMCH pump seems to be popular in all sorts of cars. I was recently watching "How It's Made: Dream Cars" and they were showing the assembly of a Caterham 7 in England.

https://lh6.googleusercontent.com/-dcAz_egIGXU/VAp7ekiN_VI/AAAAAAAABJ8/FgIrTxQ6q1I/w800-h450-no/20140904_232602.jpg

https://lh6.googleusercontent.com/-X42tjGApnos/VAp7d470Q2I/AAAAAAAABJg/rge_8mYjsDc/w800-h450-no/20140904_232626.jpg

https://lh4.googleusercontent.com/-gq-AKKivVKg/VAp7d9_2QsI/AAAAAAAABJ4/QvRskf-I9b8/w800-h450-no/20140904_232751.jpg

https://lh3.googleusercontent.com/-kZGBevKILMg/VAp7eZ9Do9I/AAAAAAAABJw/wgGhzFki6Tw/w800-h450-no/20140904_232844.jpg

https://lh4.googleusercontent.com/-1GGzsmgcdII/VAp7eyzmOYI/AAAAAAAABJ0/8SE8hEN3Lqc/w800-h450-no/20140904_232941.jpg

[OverlandMan]

So what's the trick to getting the baffle/basket out of the tank. I was reading the instructions on the fuel pump removal and it said something about releasing a tab and the assembly comes apart in two... what am I missing here?

[Henrik]

Howdy Jeff,
There is a little molded-in stud inside the tank that the innards of the tank components (baffle etc) are mounted to. Just undo the little nut and eveything will come loose. All parts can be gently compressed to fit through the hole to get them out of the tank.

[OverlandMan]

Howdy Jeff,
There is a little molded-in stud inside the tank that the innards of the tank components (baffle etc) are mounted to. Just undo the little nut and eveything will come loose. All parts can be gently compressed to fit through the hole to get them out of the tank.

I already took the 10mm nut off the stud and the assembly is loose. It just felt like I was going to break something when I was trying to pull it out. The tank access hole is too small and the assembly too large (ship-in-a-bottle anyone?). I saw something about a tab to separate the assembly into 2 pieces but I haven't solved this puzzle yet.

[David T]

I already took the 10mm nut off the stud and the assembly is loose. It just felt like I was going to break something when I was trying to pull it out. The tank access hole is too small and the assembly too large (ship-in-a-bottle anyone?). I saw something about a tab to separate the assembly into 2 pieces but I haven't solved this puzzle yet.

You have to disassemble the baffle into it's parts so you can bend the parts to fit through the hole to get them out of the tank. The real fun is putting it all back together inside the tank with one hand by feel only! That is a big reason to go with the newer design. It plops right in. No muss, no fuss, no drama, really simple.

[OverlandMan]

I started cleaning out the tank this weekend. It wasn't nearly as bad as I initially thought but still certainly in need of a good scrubbing. Here's a link to my repair blog: http://dmctx.blogspot.com/2014/09/cleaning-fuel-tank-and-components-part.html

[Szabi]

There is a little molded-in stud inside the tank that the innards of the tank components (baffle etc) are mounted to.
Hello Delorean owners, what would you do if that molded-in stud separated from the bottom of the tank? I do not really want to have it melted back to the original place, because knowing the local `experts` it can only go wrong. Shall I just leave the baffle moving freely in the tank or is there a more modern solution to replace this whole antique fuel pick-up/baffle stuff? I see Specialtauto has an alternative solution but I also found negative comments about it.

[David T]

Hello Delorean owners, what would you do if that molded-in stud separated from the bottom of the tank? I do not really want to have it melted back to the original place, because knowing the local `experts` it can only go wrong. Shall I just leave the baffle moving freely in the tank or is there a more modern solution to replace this whole antique fuel pick-up/baffle stuff? I see Specialtauto has an alternative solution but I also found negative comments about it.

You get that stud hot and melt it back into the bottom of the tank being careful not to make a hole. Or you can try epoxy but I doubt if you will have good results that way.

[Bitsyncmaster]

I think the new DMCH fuel pump with sender has it's own baffle so would not need that stud.

[burch]

The new DMCH and the new integrated SpecialTAuto units don't utilize external baffles at all. The fuel pickup (at least on SpecialT) is attached to the unit directly, and has a small mesh screen, not dissimilar from the original filter at the end of the pickup line. You don't use the old stud with the new units at all, as they are only secured from the top.

I've been running the SpecialT one for a few days now, and so far so good. Using the old baffle as a jaunty hat when I go out.

[PJ Grady Inc.]

The Hervey "tuna can" is easier to install but I still prefer the original setup to either of the aformentioned "New" designs. We only use the original style components in my shop but I am considering a new design by an American supplier. It's not on the front burner however.
Rob


The new DMCH and the new integrated SpecialTAuto units don't utilize external baffles at all. The fuel pickup (at least on SpecialT) is attached to the unit directly, and has a small mesh screen, not dissimilar from the original filter at the end of the pickup line. You don't use the old stud with the new units at all, as they are only secured from the top.

I've been running the SpecialT one for a few days now, and so far so good. Using the old baffle as a jaunty hat when I go out.

[burch]

Rob, is the original design just better at getting to the tank bottom? Seems like it would be...


The Hervey "tuna can" is easier to install but I still prefer the original setup to either of the aformentioned "New" designs. We only use the original style components in my shop but I am considering a new design by an American supplier. It's not on the front burner however.
Rob

[Szabi]

My original parts are in good condition, so maybe I`ll first try to put the stud back. I wouldn`t risk making a hole on the bottom of the tank, so I`ll look if there is a fuel resistant glue.

By the way, can someone explain what happens when the fuel level is lower than the top of the baffle? I understand the return pipe always fills the baffle, but it does not help when the fuel level in the tank is lower than the height of baffle. But then there is still much fuel in the tank, outside the baffle.

[OverlandMan]

My original parts are in good condition, so maybe I`ll first try to put the stud back. I wouldn`t risk making a hole on the bottom of the tank, so I`ll look if there is a fuel resistant glue.

By the way, can someone explain what happens when the fuel level is lower than the top of the baffle? I understand the return pipe always fills the baffle, but it does not help when the fuel level in the tank is lower than the height of baffle. But then there is still much fuel in the tank, outside the baffle.

The baffle has those little holes in it around the sides that sit maybe 1/16" or less off the bottom of the tank. If I recall, the area where the baffle attaches via the aforementioned stud, is the lowest in the tank so the gas will pool there first. If it gets below the baffle line, you're on fumes anyways and are going to be on the side of the road.

If your low-fuel light works, you'll be warned far in advance of this event.

[Bitsyncmaster]

The nice thing with the OEM setup is the fuel pickup is near the back of the tank. So when you need a lot of fuel going up hills it should have the most fuel there.

[DMCMW Dave]

I was skeptical about the sump location on the new design (closer to the front of the tank), but it's much deeper and somewhat more "leak-proof" than the original baffle so it has not been an issue. Maybe on a long hill climb with an empty tank, but we've not heard of issues.

The original baffle is centered in the tank, it's is not near the back, although the shape of the tank helps a bit.

There is a check valve in the sump to let fuel in and not out, the return line is constantly overfilling the sump, and the sump bottom is essentially sealed other than the inlet valve. If you want to see an interesting phenomenon on the new one, before you close things up, power it up. No matter how empty the tank is, all the way to almost dry, the sump will fill up and overflow immediately. The original baffle counts on the small holes to let fuel in when the tank is near empty, but they can also let the fuel out.

One criticism of this design is that (other than the gauge and low fuel light) is that you don't get any warning on running out of gas, i.e. where the original will starve on a corner and make the engine cough, the new one does a great job of really emptying the tank, so when it runs dry it's DRY.

[ccurzio]

One criticism of this design is that (other than the gauge and low fuel light) is that you don't get any warning on running out of gas, i.e. where the original will starve on a corner and make the engine cough, the new one does a great job of really emptying the tank, so when it runs dry it's DRY.

And let's face it, that's not even a valid criticism. If you're driving your car to this level, any resulting problems are your fault and yours alone.

Even if your fuel gauge is inoperative and your fuel light is burnt out, any reasonable person can still ballpark the amount of gas in the tank based on when they last filled it and how much they've driven.

[David T]

And let's face it, that's not even a valid criticism. If you're driving your car to this level, any resulting problems are your fault and yours alone.

Even if your fuel gauge is inoperative and your fuel light is burnt out, any reasonable person can still ballpark the amount of gas in the tank based on when they last filled it and how much they've driven.

It is only on more modern cars that you even get a low fuel light. On many older cars the fuel gauge was never accurate enough to run dry. You always cross-checked your trip odometer against the fuel gauge if you were going to run that low. On most cars the fuel gauge is only accurate if you are level and are either stopped or moving at a constant speed in a straight line. The Delorean was ahead of it's time on a lot of things like that low fuel light. The OEM fuel tank set-up is pretty good BUT it has to be kept clean and properly installed. This advice is also applicable to the newer DMCH fuel pump, we have yet to see what it would be like after being left stored for a lot of years with stale fuel! I doubt it would clean up as well!

[Jack]

As anyone tried this in the tank yet?
https://www.holley.com/products/fuel_systems/hydramat/parts/16-102
33596

[PJ Grady Inc.]

The pickup is more centralized with the original pickup than with the newer designs and works fine as long as the boots don't deteriorate as they will do when sitting. Modern gas formulations add further strain to the rubber parts. Additionally the cover is prone to shrinking so there can be issues. At this point in time I still prefer the original setup with those reservations but that may change as things develop.
Rob


Rob, is the original design just better at getting to the tank bottom? Seems like it would be...