No fuel coming out of injectors

[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.