Fuel System Cleaning Question

[Justin51982]

Now that I've gotten the boot open and the car is well on its way to being cleaned up, I am hoping to start one of the next well needed things which is cleaning the fuel system. I know John Hervy rebuilt the system, but that was back in 1999-00, and from what I can tell, the car has pretty much been sitting since; meaning that it needs to totally be gone through again.

I've seen and read multiple ways to clean the fuel system. I want to go the route of pulling the tank, having the injectors rebuilt and flushing the lines.

What are everyone's thoughts on this? What is the best way to pull the tank? and is there anything else I need to know/would you guys recommend?

Thanks!

[David T]

Now that I've gotten the boot open and the car is well on its way to being cleaned up, I am hoping to start one of the next well needed things which is cleaning the fuel system. I know John Hervy rebuilt the system, but that was back in 1999-00, and from what I can tell, the car has pretty much been sitting since; meaning that it needs to totally be gone through again.

I've seen and read multiple ways to clean the fuel system. I want to go the route of pulling the tank, having the injectors rebuilt and flushing the lines.

What are everyone's thoughts on this? What is the best way to pull the tank? and is there anything else I need to know/would you guys recommend?

Thanks!

You only really need to pull the tank if the master cylinder was leaking and brake fluid got all over the frame and lifted the paint. Removing the tank is not necessary to clean it. Get all of the old fuel out, take out the fuel pick-up and baffle and then wipe the inside with Acetone. Clean up the old parts. Replace anything broken and the rubber hoses if soft and/or swollen. If the boots are stiff and hard they should be replaced. If it is really bad in the tank the lines should be flushed, the metering unit rebuilt and the injectors cleaned and tested. If the car has been sitting that long you should also rebuild the brake system, clutch hydraulics, and cooling system. Change ALL of the fluids. If you insist on pulling the tank you undo everything on top, remove the bottom plate, and then stand on the tank to get it loose. Once it starts to move a 2 X 4 can be used to lever it out.

[Justin51982]

Thanks David. If you think I can get away without pulling the tank, then I'll go that route first. I was planning and re-doing the brake system and replacing the fluid with dot 5 (may be overkill through). Cooling system slipped my mind, but I would have likely got there. That's easy enough....Would you recommend pulling and having the radiator boiled or do you think that's not necessary?

Thanks again!

[djdogbone]

Alexander tells me you're going to hanging with us when we finish putting his engine back together...though that cooling system may take some effort. His is an auto and we were having issues with a fatter pipe....geez, that little coolant pipe is a bugger.

I'm no expert but I have done a few DIY things on my car.....always happy to help if I have the time.

[Justin51982]

Alexander tells me you're going to hanging with us when we finish putting his engine back together...though that cooling system may take some effort. His is an auto and we were having issues with a fatter pipe....geez, that little coolant pipe is a bugger.

I'm no expert but I have done a few DIY things on my car.....always happy to help if I have the time.

I tried to call Alex today, I'd love to come by and see his car (and yours now :) ) but I wasn't able to get a hold of him. What part of SA are you in?

[TTait]

http://dmctalk.org/showthread.php?637-How-to-clean-out-fuel-tank-and-flush-fuel-system-BEFORE-you-try-to-start-the-car

[David T]

Thanks David. If you think I can get away without pulling the tank, then I'll go that route first. I was planning and re-doing the brake system and replacing the fluid with dot 5 (may be overkill through). Cooling system slipped my mind, but I would have likely got there. That's easy enough....Would you recommend pulling and having the radiator boiled or do you think that's not necessary?

Thanks again!

Do NOT convert to DOT 5. Stay with Castrol DOT 4. There are a lot of reasons for it. If you pull the radiator and it has the plastic tanks it should be replaced. If it has green staining it should be replaced. Unless there are a lot of deposits in it you should not need to boil it out. Pull the hoses and peek inside.

[Justin51982]

After getting to the tank and draining it, it doesn't seem at all necessary to pull it. I'll just wipe it out and flush the system with SeaFoam (or similar) I went ahead and ordered a cheap fuel pump so once that's here I will flush that system.

I'll do brakes next....I would start that a lot sooner, but it's been cold. I may start it tonight anyway, I could at least blow air through the system to empty it.

After that, I'm sure I'll do the cooling system. So I'll keep everyone abreast of my progress and I'm sure I'll be asking for more advice soon.

[OverlandMan]

After getting to the tank and draining it, it doesn't seem at all necessary to pull it. I'll just wipe it out and flush the system with SeaFoam (or similar) I went ahead and ordered a cheap fuel pump so once that's here I will flush that system.

I'll do brakes next....I would start that a lot sooner, but it's been cold. I may start it tonight anyway, I could at least blow air through the system to empty it.

After that, I'm sure I'll do the cooling system. So I'll keep everyone abreast of my progress and I'm sure I'll be asking for more advice soon.

For cleaning the fuel tank. I bought a $1 small grill brush at home depot and scrubbed it with acetone on and off over a couple of days. Then wiped it out. I screwed-up and used paper towels, which left little paper debris in the tank. I waited another day for the acetone fumes to dissipate and then hit it with my shop vac to get rid of the paper towel debris. I used an iPhone, duck tape, and a paint stirrer to make a video camera for inspecting the inside of the tank.

[PJ Grady Inc.]

You only really need to pull the tank if the master cylinder was leaking and brake fluid got all over the frame and lifted the paint. Removing the tank is not necessary to clean it. Get all of the old fuel out, take out the fuel pick-up and baffle and then wipe the inside with Acetone. Clean up the old parts. Replace anything broken and the rubber hoses if soft and/or swollen. If the boots are stiff and hard they should be replaced. If it is really bad in the tank the lines should be flushed, the metering unit rebuilt and the injectors cleaned and tested. If the car has been sitting that long you should also rebuild the brake system, clutch hydraulics, and cooling system. Change ALL of the fluids. If you insist on pulling the tank you undo everything on top, remove the bottom plate, and then stand on the tank to get it loose. Once it starts to move a 2 X 4 can be used to lever it out.
I don't know Dave you must have the flexability of a teenager! I think it's easier (and safer from a fumes standpoint) to remove the tank to clean it properly if the fuel has left deposits from sitting. You can drain it easier, reach all the way in without straining, see into it better to moniter your progress, and can flush it with water and dry it after using the usual acetone bath & cotton rag treatment. But we're used to doing cars that have sat for ten years plus. If the tank isn't bad it's doable but still hard on the old back and lungs.
Rob Grady

[Justin51982]

Either way, seems like a bitch of a job......While we're on the subject, I am under the impression that the fuel filter is a nightmare of a job....Any tips there?

[OverlandMan]

Either way, seems like a bitch of a job......While we're on the subject, I am under the impression that the fuel filter is a nightmare of a job....Any tips there?

It's not that bad. You have to lift the car and pull the left rear wheel. I guess that was my biggest gripe. Installing it was pretty straightforward. Here's a URL to my blog entry for that job: http://dmctx.blogspot.com/2014/01/fuel-filter-change.html

Changing the accumulator was a bigger pain to me. All of this is much easier if you have access to a lift.

[Justin51982]

Seems a lot more straightforward than what I was understanding. Sounds like a tight fit, but should be easy enough.

[David T]

I don't know Dave you must have the flexability of a teenager! I think it's easier (and safer from a fumes standpoint) to remove the tank to clean it properly if the fuel has left deposits from sitting. You can drain it easier, reach all the way in without straining, see into it better to moniter your progress, and can flush it with water and dry it after using the usual acetone bath & cotton rag treatment. But we're used to doing cars that have sat for ten years plus. If the tank isn't bad it's doable but still hard on the old back and lungs.
Rob Grady

Yes, as we age we lose flexibility and it helps if you have long arms and the tank is not VERY bad. Pulling the tank is a job all by itself and unless you need to fix the frame or the epoxy because of a leaky master cylinder, I say suffer and try to clean it "in situ". All too often one job leads to another and then another and the project gets so big as to overwhelm and then nothing gets done. As for the fumes, if you do it outside and use a respirator and a fan, the fumes can be controlled. A Delorean is one of the very few cars where you can access the tank without having to remove it. On most of the cars where I had the honor of having to clean the tank, most of the fuel had evaporated or was used up and only the bottom inch or so was really bad. The inside sides and top are generally pretty clean. It is hard to reach all the way in to the "point" but you can always use a stick with a rag attached. Paper towels tend to break up because of the rough surface of the plastic and the Acetone. Good shop rags are the way to go, just dispose of them properly and take precautions for personal safety and fire.

[TTait]

Getting your arm in there is doable, but not particularly comfortable. If you have huge biceps it could be tough. I'd highly recommend giving it a try before pulling the tank out. I found the tough part getting back out as you lay down into the trunk with yoru arm down into the tank - good to have someone who can help pull you back out.

I've done two that way, with bad, thick sludge/tar in the bottom. Probably as bad as it can be as they sat for a dozen years with plenty of fuel in them - but it was still doable.

You might consider getting a tyvek suit and taping the sleeves to some good rubber/nitrile gloves - the tar can stain your clothes permanently and your skin for days.

[alexwolf1216]

Seems a lot more straightforward than what I was understanding. Sounds like a tight fit, but should be easy enough.

Its not that its hard, its just that you really dont want to break or strip the metal line. It runs through the frame, and not something you want to mess with. The hardest part of us messing with it was getting the banjo bolt back in from the top, there isnt a lot of clearance and there are some lines up there that caused us grief. Took well over an hour to get that stupid little bolt threaded without losing the crush washers.

[OverlandMan]

Its not that its hard, its just that you really dont want to break or strip the metal line. It runs through the frame, and not something you want to mess with. The hardest part of us messing with it was getting the banjo bolt back in from the top, there isnt a lot of clearance and there are some lines up there that caused us grief. Took well over an hour to get that stupid little bolt threaded without losing the crush washers.

I disconnected the top filter line from the fuel distributor side, then pulled the filter out and installed the line to the new filter on my workbench. This proved much easier than trying to get that connection made with the filter on the car. I do recall having to turn the filter once or twice to get everything lined-up properly.

[alexwolf1216]

I disconnected the top filter line from the fuel distributor side, then pulled the filter out and installed the line to the new filter on my workbench. This proved much easier than trying to get that connection made with the filter on the car. I do recall having to turn the filter once or twice to get everything lined-up properly.

Yeah we thought about that since we were replacing the lines with DPI's, but the connection at the bottom scared the pants off me. I would likely strip it out, then have to cry myself to sleep at night.

[OverlandMan]

Yeah we thought about that since we were replacing the lines with DPI's, but the connection at the bottom scared the pants off me. I would likely strip it out, then have to cry myself to sleep at night.

Yea, I've heard the horror stories about folks stripping that line out; however, mine came off without too much fuss so I didn't worry too much when I was re-installing.

[TTait]

Now the fuel accumulator - that one is a PITA...

[David T]

Now the fuel accumulator - that one is a PITA...

Yes it is. Small hands are useful as are flare nut wrenches (and a LOT of patience and colorful language).

[TTait]

Is there a reason the fuel accumulator could not have been near the fuel pump? Even a little lump in the access cover would have been preferable to dealing with where it is now.

[DMCMW Dave]

Is there a reason the fuel accumulator could not have been near the fuel pump? Even a little lump in the access cover would have been preferable to dealing with where it is now.

None at all. It was just packaging. We worked a bit on an 82 Ferrari Mondial last year and found that the fuel pump, filter and accumulator looked to be almost the same parts as the DeLorean (albeit about 4x the price!). They were mounted side by side next to, but outside of, the fuel tanks, just forward of the right rear tire. Which make for some unpleasant exposure to the elements, but some wonderfully short fuel lines.

[Justin51982]

None at all. It was just packaging. We worked a bit on an 82 Ferrari Mondial last year and found that the fuel pump, filter and accumulator looked to be almost the same parts as the DeLorean (albeit about 4x the price!). They were mounted side by side next to, but outside of, the fuel tanks, just forward of the right rear tire. Which make for some unpleasant exposure to the elements, but some wonderfully short fuel lines.

As ingenious as JZD was, some of what I discover leaves my scratching my head....Anything that doesn't make sense to me, I just chalk it up to the British engineering of Colin Chapman....Every English car I've had has something quirky with it...well a lot quirky.

[David T]

As ingenious as JZD was, some of what I discover leaves my scratching my head....Anything that doesn't make sense to me, I just chalk it up to the British engineering of Colin Chapman....Every English car I've had has something quirky with it...well a lot quirky.

You have to think back to when and how the car is assembled. Much of what is called "packaging" is done for the convenience of assembly or to reduce assembly costs. Most of the time little thought is given to how things will be serviced or to make things easier. For this instance, the fuel accumulator, if they figured it should not have to be changed for 5 years, then they couldn't care AT ALL how it would be serviced. Look at more modern cars with fuel injection. Have you ever had to replace the fuel pump? You have to drop the tank. With all of the plumbing and electrical it is no easy task! Some jobs in a Delorean are comparatively easy. Some you don't have to do often. When you get a 34 year old car you have to figure you will be doing a lot. Even if some things were done in the past, they may have been done so long ago as to be needed to be done again. And then there is all of the stuff that WAS done but done improperly. It is all part of the classic car experience. At least it is more affordable if you can do a lot of the work yourself even if the parts are expensive, at least you can get them easy enough!

[DMCMW Dave]

I always find it amusing that people put the blame for some of the quirky engineering designs on JZD himself. He didn't engineer the car, and I'd bet that he didn't personally have any idea where the accumulator was positioned!

[Justin51982]

I always find it amusing that people put the blame for some of the quirky engineering designs on JZD himself. He didn't engineer the car, and I'd bet that he didn't personally have any idea where the accumulator was positioned!


I didn't blame JZD....

"I just chalk it up to the British engineering of Colin Chapman....Every English car I've had has something quirky with it...well a lot quirky."

[TTait]

I always find it amusing that people put the blame for some of the quirky engineering designs on JZD himself. He didn't engineer the car, and I'd bet that he didn't personally have any idea where the accumulator was positioned!

You know, if he was still around somebody would have tried to get him to do a reality show where he actually helps rebuild and update a Delorean. If we are willing to watch Darryl Hall rebuild a farmhouse - Watching John consult on the rebuild of a Delorean and GTO would be damned good TV.

Come to think of it - imagine a show based around Ed and D1? Not good for the marquee, but you could sell a lot of "Whats your Vin?" T shirts.

[PJ Grady Inc.]

You know, if he was still around somebody would have tried to get him to do a reality show where he actually helps rebuild and update a Delorean. If we are willing to watch Darryl Hall rebuild a farmhouse - Watching John consult on the rebuild of a Delorean and GTO would be damned good TV.

Come to think of it - imagine a show based around Ed and D1? Not good for the marquee, but you could sell a lot of "Whats your Vin?" T shirts.

I must agree Ed would always put on a good show in between VIN request's and marking black X's next to names!

[TTait]

None at all. It was just packaging. We worked a bit on an 82 Ferrari Mondial last year and found that the fuel pump, filter and accumulator looked to be almost the same parts as the DeLorean (albeit about 4x the price!). They were mounted side by side next to, but outside of, the fuel tanks, just forward of the right rear tire. Which make for some unpleasant exposure to the elements, but some wonderfully short fuel lines.

So... would it be that tough to put together a fuel accumulator kit that added a good working fuel accumulator by the pump, or in another easy to reach place? You could include the parts to bypass the existing FA in the kit, but they would actually be optional in most cases - you could leave the failed one in place with no real detriment for many, many years I would think.

My FA is good right now, but next time I need to replace one...

[David T]

It doesn't make a lot of sense to create a special kit for something pretty rare. The accumulator lasts for years and even if it fails you can still get the car started. Even if such a kit was created you still have to go through the effort of putting it in which would be as much, if not more, work as just replacing the accumulator. I have replaced many accumulators, some come out pretty easy and some are more "uncooperative". Point being they are not all difficult and even the difficult ones are not impossible. I have also had trouble with the fuel filters and they are much easier to access. But, again, it is not done often so you just do it. In the process you create new curse words so don't have the children around when you do it!

[PJ Grady Inc.]

It doesn't make a lot of sense to create a special kit for something pretty rare. The accumulator lasts for years and even if it fails you can still get the car started. Even if such a kit was created you still have to go through the effort of putting it in which would be as much, if not more, work as just replacing the accumulator. I have replaced many accumulators, some come out pretty easy and some are more "uncooperative". Point being they are not all difficult and even the difficult ones are not impossible. I have also had trouble with the fuel filters and they are much easier to access. But, again, it is not done often so you just do it. In the process you create new curse words so don't have the children around when you do it!

Totally agree with you here David.

[TTait]

I've never been able to get it done at home, can't get the car up high enough to work comfortably, and the risk to the hard lines was too great, so this is one job I've consigned to pay professionals to do. Admittedly I gave up. Perhaps I should have just pushed through. Have now paid to have it done 3 times though on the two cars - one accumulator from a "budget" vendor only lasted a few years.

I understand it can be done, even at home. Probably a lot easier the second and third time. I suspect though its a tough job for a lot of owners either really struggle with it, or throw in the towel as I did and pay to have it changed out of fear of tweaking the hard lines.

My thinking was to simply supply new feed and return lines for the pump, along with proper clamps, that already had an accumulator tied in. At that point it would be a 45 minute job start to finish with no risk of damaging hard lines and no requirement to even lift the car, much less remove the center console. The old accumulator would simply be abandoned in place. The only tools required would be a screwdriver and a razor knife - and little risk of screwing anything up.

I respect the idea of keeping things original, but this is a mod I'd consider if (and when) I have to do the job again.

[OverlandMan]

I've never been able to get it done at home, can't get the car up high enough to work comfortably, and the risk to the hard lines was too great, so this is one job I've consigned to pay professionals to do. Admittedly I gave up. Perhaps I should have just pushed through. Have now paid to have it done 3 times though on the two cars - one accumulator from a "budget" vendor only lasted a few years.

I understand it can be done, even at home. Probably a lot easier the second and third time. I suspect though its a tough job for a lot of owners either really struggle with it, or throw in the towel as I did and pay to have it changed out of fear of tweaking the hard lines.

My thinking was to simply supply new feed and return lines for the pump, along with proper clamps, that already had an accumulator tied in. At that point it would be a 45 minute job start to finish with no risk of damaging hard lines and no requirement to even lift the car, much less remove the center console. The old accumulator would simply be abandoned in place. The only tools required would be a screwdriver and a razor knife - and little risk of screwing anything up.

I respect the idea of keeping things original, but this is a mod I'd consider if (and when) I have to do the job again.

When I did mine a year or so ago, the DMCH accumulator kit came with a set of motivational instructions that really helped me knock it out. I read over it a couple of times before I lifted the car on jack stands and started the process. For me, it was probably a 2-3 hour job. I had to go back and tighten the metal line after installing the accumulator because mine was leaking. Once I tightened it up, the leak was gone and the job was done. My advice would be to leave the car on jack stands and run the engine for a minute or two before you lower it back down and call it done.

It definitely was a pain, mostly just due to the location and small access area. But it is a doable DIY job even without a car lift.

[DMCMW Dave]

My thinking was to simply supply new feed and return lines for the pump, along with proper clamps, that already had an accumulator tied in. At that point it would be a 45 minute job start to finish with no risk of damaging hard lines and no requirement to even lift the car, much less remove the center console. The old accumulator would simply be abandoned in place. .

You would have to remove or at least block off the original accumulator. When it fails it has an internal pressure leak, and if you put in a second accumulator the leak would still be there (unless you capped off the small line that is tee'd to the return line). They also tend to fall apart inside so you really want the old one gone before it starts releasing bits of old rubber into the system.

You'd still need to find a place to put the new one. Functionally it can be anywhere in the pressure side of the system with a line tee'd into the return side, for convenience you'd want it near the engine or near the fuel tank, and in a somewhat protected location (from road debris). This is, I'm sure, why the current location made so much sense to the designers.

A good location might be right next to the fuel filter, but other than being outside the frame it would still be a pain to get to, and the relief line would be long. I can't think of somewhere near the tank that meets these requirements. It could, for example, be on the side of the frame opposite the A/C accumulator, but being right behind the tire seems a bit sketchy.

But in either case you'd want to remove the old one.

[Delorean Industries]

One of the many perks associated with our EFI system. The accumulator is no longer required and can be either left in place or removed completely depending on preference.

[TTait]

I guess I knew at some level if it was that simple someone would have figured it out in the 80's.

Chalk up another point for EFI maybe?

[BABIS]

One of the many perks associated with our EFI system. The accumulator is no longer required and can be either left in place or removed completely depending on preference.

Hello Josh,
the removal of the accumulator in your efi kit is applicable due to new direct fuel lines or do you supply an elimination "kit" for the original lines?

[Delorean Industries]

Hello Josh,
the removal of the accumulator in your efi kit is applicable due to new direct fuel lines or do you supply an elimination "kit" for the original lines?

removal kit for the original lines is available. Takes a bit of work but gets the POS out of the system completely.

[David T]

removal kit for the original lines is available. Takes a bit of work but gets the POS out of the system completely.

Does that "bit of work" include lifting the body off the chassis? Or do you abandon the old lines and run new ones underneath?

[Delorean Industries]

Does that "bit of work" include lifting the body off the chassis? Or do you abandon the old lines and run new ones underneath?

body comes off unless you already have our stainless lines installed which makes it very easy compared to using the stock compression fittings.