No fuel coming out of injectors

[MonkeyFella95]

Hi, hope someone here can help point me in the right direction, this is driving me crazy.

I've recently replaced all injectors, fuel lines and put in a professionally rebuilt fuel distributor. I jumped the RPM relay to test it, put the injectors in jars and pushed down on the intake and... nothing. After about a minute of the fuel pump running one of the fuel lines for the accumulator ruptured... F***.

So after replacing the fuel lines there, and put in a new accumulator while I was at it, I'm back to trying to figure out why the injectors aren't spraying at all. I've ran the pump since then (making sure not to leave it running for long this time so I don't explode the new fuel lines) and the same thing. Clearly I'm not getting low pressure from the pump because it had enough pressure to rupture the fuel line, but I'm totally at a loss for how to figure out why not enough pressure is getting to the injectors. I can feel the resistance when pressing down on the air intake when the pump is running and I know fuel is getting to the distributor.

When I got the car the engine ran but had an over-fueling issue because of the distributor being stuck in the fully open position. Clearly I've messed something up here but I have no idea how to diagnose what the issue is. Any help would be appreciated!

[82DMC12]

Probably have the lines backwards with the check valve blocking flow

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[MonkeyFella95]

Probably have the lines backwards with the check valve blocking flow

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Thanks for the reply. I've not replaced the lines at the fuel pump (yet) where the check return valve is, the fuel pump was clearly serviced at some point in the 2000's so isn't original and worked a year ago so there's no chance I've messed that up unless I'm not understanding something

[Bitsyncmaster]

So this is the first time you tried the new fuel distributor? Since your line ruptured, my guess would be a problem with the PPR not releasing any back flow. That would also explain why your not getting any flow at the injectors (it can't prime the FD).

[MonkeyFella95]

So this is the first time you tried the new fuel distributor? Since your line ruptured, my guess would be a problem with the PPR not releasing any back flow. That would also explain why your not getting any flow at the injectors (it can't prime the FD).

Yes this is the first time I’ve tried the new distributor. I’d assumed this was something I’d caused as the distributor was professionally rebuilt and supposedly tested before receiving it. I’ll look into the PPR. Really appreciate your reply.

I’ve been reading to try and understand exactly how the PPR works, it sounds like your saying that the regulator isn’t opening to allow fuel to return to the tank causing pressure to build up between the pump and the distributor which makes sense but I’m not clear on why that would cause the distributor to not prime, would that be because air is stuck in the system? Do you have any idea what might be causing the PPR to not be releasing any flow back? Sorry for all the questions, really appreciate you taking the time to reply to my post.

[MonkeyFella95]

Taken out the PPR and all looks okay

70726

Then I put a endoscope in to see if I could see anything, and this doesn’t look right to me. I’m not sure what that is in the end there but it doesn’t look like it should be there.

70727

[Bitsyncmaster]

That endoscope photo does look like something is broken off in the FD. The PPR photo does look normal as far as I can remember.

[MonkeyFella95]

Well time to complain to DeLorean GO about this. Anyone reading this my advice is do not ever buy a rebuilt distributor from them!

[Bitsyncmaster]

Well time to complain to DeLorean GO about this. Anyone reading this my advice is do not ever buy a rebuilt distributor from them!

If you have a compressor, try to blow it out with air into the return port.

[MonkeyFella95]

Well time to complain to DeLorean GO about this. Anyone reading this my advice is do not ever buy a rebuilt distributor from them!

I retract that completely. After emailing Arran from DeLorean GO he replied within minutes, on a Sunday, saying he will send out a new unit tomorrow for me.

[David T]

Recheck that you have correctly attached all of the fuel lines to the fuel distributor properly. I doubt the problem is with the F/D. When they are rebuilt they are tested. You say you had an "overfueling" problem originally. One possible cause is a blocked return line to the tank. Do not go by how the lines were, get a diagram and make sure each line goes where it is supposed to. A PO could have incorrectly installed the fuel lines. Next, get a fuel pressure gauge on the fuel system so you can see what is happening. This should be done before you put another F/D in and possibly damage that one too or another accumulator or hoses.

[dmcman73]

First: If you replaced the lines at the fuel pump, make sure you didn't accidently swap them around. A quick check would be to remove the line coming off the fuel filter going to the fuel distributor and place it in a bucket then remove the hose going from the fuel distributor to the return of the tank (it's one of the double banjo fittings on the right side of the FD) and place that in the same bucket. You'll want two people for this, have someone jump the RPM relay and note where the fuel comes spraying out, if it's spraying out from the return line, you'll need to swap the hoses up front.

Also, anytime you replace the fuel distributor with a rebuilt or new one, you have to set the base mixture adjustment using the CO adjuster screw. It's simple to do but everyone always overlooks this part and struggles getting their car to start.

IMPORTANT: THERE IS NO STOPPER ON THE co ADJUSTER SCREW WHICH MEANS YOU CAN UNSCREW IT TOO FAR OUT OR IN AND IT CAN FALL INTO THE MIXTURE UNIT, TAKE CARE NOT TO TURNT HE SCREW TOO FAR OUT OR IN.

1. After attaching all lines to the fuel distributor, rap a large rag around the FD to absorb an fuel coming out then remove a hose from the FD that goes to a fuel injector (I usually remove the one going to injector 1 since it's easier to contain the fuel coming out of it. Don't worry, the fuel will not come spraying out of the port unless you press the air meter flap down all the way.

2. Have someone jump the RPM relay to turn on the pump. I highly suggest you have a second person doing this so if there is any fuel related issues they can pull the jumper off quickly.

3a. NOTE: WHILE DOING THIS STEP MAKE SURE YOU ARE NOT PUSHING DOWN ON THE ALLEN KEY AS YOU WILL BE PRESSING DOWN THE AIR METER FLAP THROWING OFF ALL MEASUREMENTS. If there is no fuel dribbling out after turning on the fuel pump, keep going with step 3a, if there is fuel dribbling out, skip down to 4. Use a long 3mm allen key to turn the CO adjustment clockwise (richen the fuel) slowly until it begins to dribble out, take your hand off the allen key to make sure you are not applying any pressure down on the CO screw and dab the port with a rag to wipe away fuel, if the fuel is still dribbling out, then go to the next step.

3b. Once the fuel begins to dribble out, slowly back off (counter clockwise to lean the fuel mixture) until it just about stops. Take your hand off the allen key again, dab the port with a rag to wipe fuel away and monitor it. If the fuel just stopped dribbling out, pull the jumper off the RPM relay, reattach the hose to the FD and clean up any spilled fuel. and you can skip steps 4a below.

4. If fuel is dribbling out as soon as you jump the RPM relay, back off the CO adjustment by turning it counterclockwise to lean the fuel out just until it stops. Once it stops, turn it clockwise until it begins to dribble out again and then back off counterclockwise until it just stops, again. reattach the hose and clean up any fuel spilled.

5. Reattach the RPM relay

That's it, once you make the above adjustments, you should be able to start the car and let it run to warm up to operating temps. Once it does, you can attach a DWELL meter up to the car are precisely set the CO adjustment. If you need instructions on how to set the CO with a DWELL meter, Chris Miles made an excellent video on how to do that here: https://www.youtube.com/watch?v=HKT_i82VtIo

Also, if you feel that you may have flooded the engine during the adjustments, pop the inertia switch under the dash to cut off the fuel pump, crank the engine until you start to hear it about to start, stop cranking and rest the inertia switch. That will clear out all the fuel that flooded the engine.

[dn010]

I retract that completely. After emailing Arran from DeLorean GO he replied within minutes, on a Sunday, saying he will send out a new unit tomorrow for me.

You might also consider that DeLorean Go is not the company rebuilding or testing these before shipping them out. If anyone, blame the rebuilder.

[ssdelorean]

You might also consider that DeLorean Go is not the company rebuilding or testing these before shipping them out. If anyone, blame the rebuilder.

On a similar note...
If you got a part that was recently cleaned, coated, refurbished, etc., check it for other tiny parts lodged inside. My friend had a teeny-tiny screw jammed inside of a fuel line end fitting. It had been cleaned and zinc coated along with a bunch of other parts. Often everything is in one pot/pan when cleaning/coating.

[Michael]

I for one got a rebuilt FD and CPR from DeLoreanGo about 3 or 4 years ago and it's been flawless since.

Have you set the base mixture on the air meter yet? You replaced the FD so chances are, your mixture is way off now.

Loosen and remove one of the injectors. Set your Allen wrench in the mixture set screw and jump the RPM relay. Slowly richen the mixture until you see fuel coming from the loose injector. That should get you close enough to run and dial in the mixture once you are at temp.

[MonkeyFella95]

So to update everyone I realised I really rushed to judgement on the FD and PPR (Sorry Arran). I've not sent mine back for a replacement because I wanted to test to know definitively what the cause is, so far I really don't know what to make of the results.

With the fuel supply line disconnected from the FD I get good flow from the pump. With the fuel supply connected and the fuel return disconnected from the hardline I get good flow out of the FD (although after 20 seconds I started hearing strange metal sounds and the pump get louder so I disconnected the pump quickly to avoid blowing anything else up). If I disconnect one of the injectors completely I get no flow at all and when I press down on the intake I get progressively more fuel, so not an issue of the CO adjustment.

All of this is exactly what I would expect if everything is functioning except the injectors still never open and it seems that when the supply line is connected to the FD pressure starts building up. I'm going to replace the fuel pump lines, which I've not touched yet, over the weekend and test the flow out there back to the tank. Although because of the noises it made with the return line disconnected from the hardline it seems like the issue must be something in the engine bay.

Totally out of ideas on the cause of this, doesn't seem to make any sense. It could still be the FD / PPR. I'm going to test with a fuel pressure tester over the weekend as well so will have more data then.

[dmcman73]

So to update everyone I realised I really rushed to judgement on the FD and PPR (Sorry Arran). I've not sent mine back for a replacement because I wanted to test to know definitively what the cause is, so far I really don't know what to make of the results.

With the fuel supply line disconnected from the FD I get good flow from the pump. With the fuel supply connected and the fuel return disconnected from the hardline I get good flow out of the FD (although after 20 seconds I started hearing strange metal sounds and the pump get louder so I disconnected the pump quickly to avoid blowing anything else up). If I disconnect one of the injectors completely I get no flow at all and when I press down on the intake I get progressively more fuel, so not an issue of the CO adjustment.

All of this is exactly what I would expect if everything is functioning except the injectors still never open and it seems that when the supply line is connected to the FD pressure starts building up. I'm going to replace the fuel pump lines, which I've not touched yet, over the weekend and test the flow out there back to the tank. Although because of the noises it made with the return line disconnected from the hardline it seems like the issue must be something in the engine bay.

Totally out of ideas on the cause of this, doesn't seem to make any sense. It could still be the FD / PPR. I'm going to test with a fuel pressure tester over the weekend as well so will have more data then.

Did you set your base mixture as I described in post #12? If you don't your mixture will be way off which means (depending where the mixture is off) your injectors will not open or they will spray/drip no matter what.

Also, have you connected a fuel gauge up to test you working and system pressure?

If you did not do either of those, then you're not out of ideas, you need to perform the above two any time you install a different or rebuilt fuel distributor.

[MonkeyFella95]

Did you set your base mixture as I described in post #12? If you don't your mixture will be way off which means (depending where the mixture is off) your injectors will not open or they will spray/drip no matter what.

Also, have you connected a fuel gauge up to test you working and system pressure?

If you did not do either of those, then you're not out of ideas, you need to perform the above two any time you install a different or rebuilt fuel distributor.

At this point I'm mainly concerned about the pressure building up. If I don't sort that out I don't have the time to calibrate the mixture. The injectors don't spray at all even with the flap fully down and with the injectors off fuel starts flowing as soon as any pressure is put on it. Maybe I've put too much focus on that, if it's unrelated to the issue of pressure building up then I'll deal with it later.

By out of ideas I meant out of ideas on the cause, not out of ideas for tests. I'm going to do a working and system pressure test this weekend which should be telling, I've not had a test kit until recently. I certainly should have done that before my fuel lines exploded but I didn't expect that to happen, expensive lesson learnt!

[dmcman73]

At this point I'm mainly concerned about the pressure building up. If I don't sort that out I don't have the time to calibrate the mixture. The injectors don't spray at all even with the flap fully down and with the injectors off fuel starts flowing as soon as any pressure is put on it. Maybe I've put too much focus on that, if it's unrelated to the issue of pressure building up then I'll deal with it later.

By out of ideas I meant out of ideas on the cause, not out of ideas for tests. I'm going to do a working and system pressure test this weekend which should be telling, I've not had a test kit until recently. I certainly should have done that before my fuel lines exploded but I didn't expect that to happen, expensive lesson learnt!

Then connect a fuel gauge on your system and test the pressures. You should see 60-75PSI with the valve closed on the fuel pressure tester.

One place to look at is the fuel accumulator. Pull the small hose off the end of it (leave the two larger connections alone), some fuel should come out from there, that's normal. If you have another piece of hose that is the same diameter, slip it over the nipple of the accumulator and point it downwards into a pail. Jump start the RPM relay to get the fuel pump going. You should see some fuel come out of that nipple for a few seconds and then stop. If it does not stop and it is coming out like a garden hose after about 5 seconds, then the diaphragm inside the accumulator is damaged and it needs to be replaced.

Also, did you pull all the injectors off, jump the fuel pump, press down on the flap and see if fuel is coming out from the ends of the fuel inject hoses? If so, was fuel coming from all of them?

[Bitsyncmaster]

I'm pretty sure the accumulator has an orifice to limit fuel flowing back to the tank if the bladder inside leaks. So even if it ruptures it should not stop the engine from running.

You do need to put a gauge on the system to read primary pressure. I once tested pressure at the pump supply hose so it did not have the PPR limiting it. When I did that the pressure instantly pegged my 100 PSI gauge so I think your PPR must be limiting it somewhat.

[MonkeyFella95]

Then connect a fuel gauge on your system and test the pressures. You should see 60-75PSI with the valve closed on the fuel pressure tester.

One place to look at is the fuel accumulator. Pull the small hose off the end of it (leave the two larger connections alone), some fuel should come out from there, that's normal. If you have another piece of hose that is the same diameter, slip it over the nipple of the accumulator and point it downwards into a pail. Jump start the RPM relay to get the fuel pump going. You should see some fuel come out of that nipple for a few seconds and then stop. If it does not stop and it is coming out like a garden hose after about 5 seconds, then the diaphragm inside the accumulator is damaged and it needs to be replaced.

Also, did you pull all the injectors off, jump the fuel pump, press down on the flap and see if fuel is coming out from the ends of the fuel inject hoses? If so, was fuel coming from all of them?

I've replaced the fuel accumulator with a brand new one after this issue started so it's not the accumulator. Yes pulled all the injectors off and get good flow out of all of the hoses.

I'll update on Sunday after I've done the pressure test

[MonkeyFella95]

Okay so measured the control pressure, cold obviously as I can't get the engine to run.

On the first run the pressure was 1.5 bar which is too low obviously which I knew it would be given the injectors aren't opening. Pressure was no different with the valve closed or open which is to be expected with the engine being cold. The second test I did it was 1 bar and on the third, and every time I've tried to test it since, it was 0. No leaks anywhere and I could tell that fuel was still getting to it because fuel came out when the release valve was pressed, just not enough pressure to register on the gauge. Through this the pump noises have got worse and worse.

I turned to testing the pressure directly out of the pump and it wouldn't get any higher than 2 bar so I know there is an issue with the pump and that needs to be replaced.

It doesn't explain why the fuel line exploded before, but my working assumption currently is that there was a blockage in the accumulator that's since been replaced that caused the pressure to build up. And the only reason my FD and injectors "worked" before I replaced them was because the FD had the pin stuck in the fully open position and the injectors were also leaking at lower pressure.

If anyone else has a different interpretation of the results I'd be interested to hear them but I'll put in an order for a new pump next week.

[dmcman73]

Okay so measured the control pressure, cold obviously as I can't get the engine to run.

On the first run the pressure was 1.5 bar which is too low obviously which I knew it would be given the injectors aren't opening. Pressure was no different with the valve closed or open which is to be expected with the engine being cold. The second test I did it was 1 bar and on the third, and every time I've tried to test it since, it was 0. No leaks anywhere and I could tell that fuel was still getting to it because fuel came out when the release valve was pressed, just not enough pressure to register on the gauge. Through this the pump noises have got worse and worse.

I turned to testing the pressure directly out of the pump and it wouldn't get any higher than 2 bar so I know there is an issue with the pump and that needs to be replaced.

It doesn't explain why the fuel line exploded before, but my working assumption currently is that there was a blockage in the accumulator that's since been replaced that caused the pressure to build up. And the only reason my FD and injectors "worked" before I replaced them was because the FD had the pin stuck in the fully open position and the injectors were also leaking at lower pressure.

If anyone else has a different interpretation of the results I'd be interested to hear them but I'll put in an order for a new pump next week.

Do you have the original pump setup or the new GM all in one pump? If you have an original setup, the pump could be bad or the fuel line going from the inlet of the pump in the tank to the filter at the bottom of the tank is either kinked or it split open which would explain your fuel pressure issues.

[MonkeyFella95]

Do you have the original pump setup or the new GM all in one pump? If you have an original setup, the pump could be bad or the fuel line going from the inlet of the pump in the tank to the filter at the bottom of the tank is either kinked or it split open which would explain your fuel pressure issues.

I have the original pump setup. Would quite like one of the new ones but DeLorean Texas is out of stock and the DeLorean industries one is $600.

I did think of that as I?ve heard other people having that issue. The baffle in my tank is gone and the filter screen is at the end of a short hard hose that has it just about touching the bottom of the tank, not an ideal setup but the hose is definitely not kinked and I can?t see any cracks in it so I?m fairly sure it?s the pump itself.

Either way I?m going to get a baffle and a proper hose with a stainless spring insert to replace the hacky setup.

[dn010]

These pumps are not all that expensive, just search 0 580 254 909 fuel pump. I think I got mine on Amazon, got two of them actually just to be safe. I'm also still using the original setup with the "updated" (hardened) weird pickup hose going to the baffle, I don't use a spring inside mine and it has been fine for decades. I'm sure you can find a baffle setup easily from someone who converted otherwise you can find everything at D-Go.

[MonkeyFella95]

These pumps are not all that expensive, just search 0 580 254 909 fuel pump. I think I got mine on Amazon, got two of them actually just to be safe. I'm also still using the original setup with the "updated" (hardened) weird pickup hose going to the baffle, I don't use a spring inside mine and it has been fine for decades. I'm sure you can find a baffle setup easily from someone who converted otherwise you can find everything at D-Go.

I meant it would be nice to have one of the new all in one style pumps like 107000 from DeLorean Texas. Good to know the part number but DeLorean GO it?s a similar price and I feel like I owe them after wrongfully blaming their FD 😅

[dn010]

I know what you meant, all I was trying to say is that the original setup, although for some can be finicky at times, works just fine. Let us know how what happens with the new pump installed.

[MonkeyFella95]

Sorry for the delayed update, it’s been a very hectic month. I’ve installed the new pump and baffle and it works and the engine starts! So it was the pump the entire time.

My profound apologies to DeLorean GO for blaming their FD. I really should realise that it’s far more likely I’ve missed something than a professionally rebuilt part isn’t working.

Engine running the best since I’ve had it now, although still not running quite right. While cold it gets close to stalling unless I rev it a bit and when warm, although stable, it idles at about 1000RPM. More investigation needed but it’s such a relief to see it running again and no more smoke out of the exhaust or an overwhelming smell of petrol like before. Thanks everyone for your help!

[AugustneverEnds]

Sorry for the delayed update, it?s been a very hectic month. I?ve installed the new pump and baffle and it works and the engine starts! So it was the pump the entire time.

My profound apologies to DeLorean GO for blaming their FD. I really should realise that it?s far more likely I?ve missed something than a professionally rebuilt part isn?t working.

Engine running the best since I?ve had it now, although still not running quite right. While cold it gets close to stalling unless I rev it a bit and when warm, although stable, it idles at about 1000RPM. More investigation needed but it?s such a relief to see it running again and no more smoke out of the exhaust or an overwhelming smell of petrol like before. Thanks everyone for your help!

Bravo! Glad to hear you solved your problem and it wasn't too terrible.

You had your fuel distributor rebuilt, how about the control pressure regulator (warm up regulator)? If it's original and hasn't been rebuilt that's where I would start looking.

[David T]

Bravo! Glad to hear you solved your problem and it wasn't too terrible.

You had your fuel distributor rebuilt, how about the control pressure regulator (warm up regulator)? If it's original and hasn't been rebuilt that's where I would start looking.

Since you installed a rebuilt F/D did you properly adjust the mixture screw? The rebuilder can't set that for you, it must be adjusted on YOUR running car. You could also have a bunch of small air leaks that must be fixed before you can adjust the mixture properly. You could also have a problem with the CPR. Best way to figure that out is to get a pressure gauge on the fuel system and watch the pressures as the motor warms up. If it has been a long time since the last tune-up, you may need one. Same goes for the O2 sensor and the valve adjustment.

[MonkeyFella95]

I've already replaced all the vacuum lines and the O2 sensor. I think it's likely the CPR, that and the frequency valve are the only original parts in the fuel system now. I'll connect a pressure gauge and test it in the next few days. I've not adjusted the CO mixture yet, I want to be sure that everything else is working correctly before doing that, my car still had the original factory seal on it when I got it, I've already drilled it out and replaced it with a bung ready to do the adjustment after I know everything else is in spec. Out of curiosity I did connect a dwell meter to see what the measurement was but the dwell was stuck at 87-90, not sure if its because I'm using a digital meter or because there's an issue with the lambda system but I'll look at that more when I've tested the CPR properly.

[David T]

I've already replaced all the vacuum lines and the O2 sensor. I think it's likely the CPR, that and the frequency valve are the only original parts in the fuel system now. I'll connect a pressure gauge and test it in the next few days. I've not adjusted the CO mixture yet, I want to be sure that everything else is working correctly before doing that, my car still had the original factory seal on it when I got it, I've already drilled it out and replaced it with a bung ready to do the adjustment after I know everything else is in spec. Out of curiosity I did connect a dwell meter to see what the measurement was but the dwell was stuck at 87-90, not sure if its because I'm using a digital meter or because there's an issue with the lambda system but I'll look at that more when I've tested the CPR properly.

There are a LOT more places for vacuum leaks besides the hoses. Injector seals, gaskets, screws, "O" rings, etc. The only sure way to know is to do a smoke test.

[cis6409]

when the dwell is reading 87-90 it usually means it's too rich and needs to be leaned out (counter clockwise turn) when the time comes to adjust it.
Definitely fixing and getting everything else checked out is the way to go before adjusting it.

I had a similar issue on mine but when it came to leaning it out it still read 87-90 no matter what.
After a bit of head scratching and conversations with others found I had a short to ground on the lambda ecu which was causing the high steady reading. Replaced the lambda ecu and everything started working again

Good luck with the diagnosing

Shane

[82DMC12]

Just do a smoke test to rule out vacuum leaks. This smoke machine works great -

https://www.amazon.com/AutoLine-Pro-Automotive-Detector-Diagnostic/dp/B07JVT1NG2

You have to seal up the air meter plate before using the smoke machine. I've done this using a latex balloon and a very large zip tie. With the air cleaner cover off, inject the smoke into the hose that goes between the air cleaner cover and the oil filler / PCV mesh. If you have no leaks, eventually all you will find is smoke coming out of the dip stick tube (not an issue).

Technically you could have a vacuum leak that only occurs when the engine is hot, so you might do a cold test and a hot test just to be 100% if you don't really know how the vacuum routing works when hot vs cold.

[MonkeyFella95]

Thanks for the advice, I'll order a smoke testing machine to check for vacuum leaks.

Tested the primary and control pressure cold, primary pressure was low (about 58PSI / 4 bar ) which explains why it struggles during warmup so I checked the voltage at the pump and it's only 9.5V so I'm losing about 4V somewhere which would explain the low primary pressure. My plan is to replace all the grounding bolts I've already cleaned with new brass bolts and add a new grounding point to the frame by the interia switch.

[Bitsyncmaster]

Thanks for the advice, I'll order a smoke testing machine to check for vacuum leaks.

Tested the primary and control pressure cold, primary pressure was low (about 58PSI / 4 bar ) which explains why it struggles during warmup so I checked the voltage at the pump and it's only 9.5V so I'm losing about 4V somewhere which would explain the low primary pressure. My plan is to replace all the grounding bolts I've already cleaned with new brass bolts and add a new grounding point to the frame by the interia switch.

Check that two pin connect near the fuel pump. You can also check the voltage at the RPM relay.