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Thread: Deciphering Fuel Enrichment Relay Setup

  1. #11
    Senior Member NckT's Avatar
    Join Date:  Jun 2011

    Location:  Yorkshire UK

    Posts:    198

    My VIN:    No. 4068

    It's too lean.
    RIP Rob van de Veer Top bloke

    I say Sir, I must be mad, one loves fixing K-Jet !

    Make sure there's plenty in the tank for the weekend chaps....

  2. #12
    Senior Member
    Join Date:  May 2011

    Location:  Northern NJ

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    My VIN:    10757 1st place Concourse 1998

    It could be too lean but do you really trust the O2 sensor? It could be contaminated and isn't putting out enough voltage for the gauge to get a good reading. I would try a new O2 sensor. BTW, it doesn't have a heater in it so it takes a while for it to start outputting a voltage.
    David Teitelbaum

  3. #13
    Member
    Join Date:  Feb 2017

    Location:  Madison, MS

    Posts:    87

    My VIN:    3455

    Too lean crossed my mind, given the gauge reading, but I don't really trust the gauge since it came with the car and I'd never seen it actually working. I searched for symptoms of running too lean, but surprisingly couldn't find much. The O2 sensor is relatively new from Autozone, but could be bad. I've driven it as much as 30 min without seeing a reading on the gauge, so think it's warmed up enough to supply a signal. It has been connected but hasnt been installed in the bung until last weekend. I'm willing to spend $20 and try a new one. I ordered a dwell meter earlier today to see if I need to adjust the mixture, but I've read enough on here to know I need to verify several other system components are in order first.

    I also ordered new silicone vac lines just to be thorough, as I'm also trying to get the vacuum system back to the island turbo specs. I don't have a vacuum delay valve (ordered that too) and instead of the hose that would connect to it, the CPR is capped off on that side.

  4. #14
    Senior Member
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    Well, you are correct in trying to get back to "stock" configuration as far as the Island Turbo set-up is concerned. The CPR may have been disconnected/modified so as to give an additional bit of fuel. It may not function correctly so check it with a pressure gauge as the car warms up once you get it reconnected. I would also confirm timing and advance to make sure it was modified for the Island set-up. Many of the Island cars were modified over and above what the documentation said in order to get more fuel out of the K-Jet system. Some also tried water/meth injection to get more boost with the stock pistons. if you go with cats you don't want to run too rich, you will burn them up.
    David Teitelbaum

  5. #15
    Member
    Join Date:  Feb 2017

    Location:  Madison, MS

    Posts:    87

    My VIN:    3455

    I got a dwell meter this weekend, set it to 4 cyl, and hooked it up. With the engine off, it read 87. With the engine on and warmed up, it pretty much just sat on 58. I swapped in a new O2 sensor and no change. I read somewhere that if it doesn't bounce around, the O2 sensor is disconnected. I now have the ECU/O2 on the relay i mentioned at the start of this thread, so to rule that out I removed it and connected the O2 sensor straight to the ECU; still no change. I did some reading on here and cleaned the contacts on the ground near the RH intake runner near the FV, and that didn't make any difference either.

    Should I suspect the lambda ECU might be bad or is there something else I should rule out first? I'll also note that the A/F meter behavior didn't change with the new O2 sensor. The LEDs are still very dim and read in the lean range.

    Also, in reading up on the ECU, it seems there's a silver (10106 and a black one (110067). Mine is silver, but what's the difference?

    In the meantime, everything seems to be running fine again. I'm not planning to change anything while I'm waiting on new silicone vacuum hoses and injector seals to come in at which point I'll start ruling stuff out from the valley up.

  6. #16
    Senior Member
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    Location:  Northern NJ

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    You need to figure out why you aren't getting into "Closed Loop". Doubtful the ECU is bad, more likely it isn't getting a good O2 signal or the ground is not good. The O2 signal is very low voltage so any problems getting it to the ECU (or the ground) and the ECU can't "see" it. Probably why the A/F meter isn't working right either.
    David Teitelbaum

  7. #17
    Member
    Join Date:  Feb 2017

    Location:  Madison, MS

    Posts:    87

    My VIN:    3455

    Problem solved! Well, the most recent problem anyway...

    I've probably noticed this a dozen times and never though anything of it. There was an old vampire tap on the SHIELDED O2 sensor wire running to the ECU. I popped it off, massaged the wire and 'bandaged' it with some electrical tape. Now the A/F gauge is working perfectly and I'm getting ~40-44 on the digital dwell meter. Idle sounds good and car is running well. I'm guessing someone tried to tap the AF meter here instead of closer to the O2 sensor, it didn't work, and that's why i found the signal wire tucked under the dash.

  8. #18
    Senior Member NckT's Avatar
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    Location:  Yorkshire UK

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    We call them scotch-locks. ... and I HATE them

    Well done in sorting the problem out. I hope it runs nice now
    RIP Rob van de Veer Top bloke

    I say Sir, I must be mad, one loves fixing K-Jet !

    Make sure there's plenty in the tank for the weekend chaps....

  9. #19
    Senior Member
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    8,570

    My VIN:    10757 1st place Concourse 1998

    You need to wire up the A/F gauge correctly so it can work. Small problem now that the motor is running better. You should go over the whole "system" wire by wire as to what was modified and how for the Island Turbo set-up and try to get it working as it should.
    David Teitelbaum

  10. #20
    Member
    Join Date:  Feb 2017

    Location:  Madison, MS

    Posts:    87

    My VIN:    3455

    Quick update to close the loop - it’s been a busy few weeks but I finally had time to sort everything out and install a new fuel pump while I was at it. For some reason or another I was getting suspicious that I was losing fuel pressure shortly after my last post. I know the accumulator was replaced by the previous owner, so I decided to take a look at the fuel pump and found there was no pump cover and the boot was filled with gas or water...or water that smelled like gas. I wicked it out with a rag, but decided to just replace the pump as it was original and the electrical contacts were rusted beyond repair. While I was waiting on that, I decided to dig into the valley to install my new silicone vacuum hoses. It wasn’t too bad down there but I did need a new heater pipe and a few new hoses. Took the plunge on a new water pump too, again b/c I figured the original was on borrowed time. Got everything back together last weekend, including the new fuel pump. The old vac lines were pretty brittle in the valley and I must have had a leak somewhere b/c the car now idles better than ever. I now have the vac lines routed according to the turbo manual. Even though the idle sounded good and the dwell was between 35-45, I noticed the engine stuttered on acceleration up to 25k rpms in all gears. Double checked everything - wires, injectors, plugs, fuel pump hoses and connections. Ultimately, an ever so slight adjustment to the mixture seems to have cleared things up.

    For now, everything seems good - fingers crossed things stay that way!

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