FRAMING JOHN DELOREAN - ON VOD www.framingjohndeloreanfilm.com
Page 5 of 6 FirstFirst ... 3 4 5 6 LastLast
Results 41 to 50 of 52

Thread: Proofing my work after fuel distribution re-assembly?

  1. #41
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,000

    My VIN:    03572

    I have checked many cars for primary pressure and they always seem to run at 68 to 70 PSI. Mine was the same way. I shimmed it up to 75 PSI also. I did not notice any improvement but I'm running a stock (mechanical wise) engine.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  2. #42
    Senior Member
    Join Date:  Mar 2016

    Posts:    182

    SUCCESS! SHE'S IDLING!

    The o-ring provided with the intake rebuild kit didn't seat very well between the fuel distributor and the mixture unit body. I suspected it wasn't quite right upon installation, but didn't think much of it. It had about 1/4" of play. Luckily, I had a spare o-ring laying around that provided a nice snug fit there. Whew!!! Now, all I need to do is tune in my mixture/lambda setting, and I should be good to go for the foreseeable future, knock on wood!

    Thanks to this whole community. You guys are the best!!!!! I don't think I would have solved this without you!!!

  3. #43
    Senior Member NckT's Avatar
    Join Date:  Jun 2011

    Location:  Yorkshire UK

    Posts:    198

    My VIN:    No. 4068

    Well done!

    I'd still look into that fuel pressure again now the engine is running etc to make sure all is within spec etc
    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....

  4. #44
    Senior Member NckT's Avatar
    Join Date:  Jun 2011

    Location:  Yorkshire UK

    Posts:    198

    My VIN:    No. 4068

    Quote Originally Posted by Bitsyncmaster View Post
    I have checked many cars for primary pressure and they always seem to run at 68 to 70 PSI. Mine was the same way. I shimmed it up to 75 PSI also. I did not notice any improvement but I'm running a stock (mechanical wise) engine.
    I noted that it affected the air to fuel ratio at the higher end of the rev range under load on a rolling road in 2009 at a "Euro tec" event here in UK that was repeatable on 10+ cars (oxygen sensor signal wire disconnected disconnected to negate closed loop feedback).

    Adding the shims to spec was the best result for power / torque AFR compromise.

    For stock k jet with a performance exhaust, it was found that increasing the primary pressure to 5.3 to 5.4 bar corrected the leaning out at the higher revs from 3500 to 6000 with standard fuel adjustment, both for lambda and non lambda k jet (for the 5 cars at the time of test on the dyno day). These have had repeatable results too since then, so the re shimming is worthwhile for sure. We've had to get the shims specially made though in 0.25mm .5mm 1.0mm thicknesses so that the pressure can be done within the spec.
    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....

  5. #45
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,000

    My VIN:    03572

    Quote Originally Posted by NckT View Post
    I noted that it affected the air to fuel ratio at the higher end of the rev range under load on a rolling road in 2009 at a "Euro tec" event here in UK that was repeatable on 10+ cars (oxygen sensor signal wire disconnected disconnected to negate closed loop feedback).

    Adding the shims to spec was the best result for power / torque AFR compromise.

    For stock k jet with a performance exhaust, it was found that increasing the primary pressure to 5.3 to 5.4 bar corrected the leaning out at the higher revs from 3500 to 6000 with standard fuel adjustment, both for lambda and non lambda k jet (for the 5 cars at the time of test on the dyno day). These have had repeatable results too since then, so the re shimming is worthwhile for sure. We've had to get the shims specially made though in 0.25mm .5mm 1.0mm thicknesses so that the pressure can be done within the spec.
    +1...good info.

    I had to add quite a lot of shim to get mine up to 75 PSI.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  6. #46
    Senior Member
    Join Date:  Mar 2016

    Posts:    182

    Quote Originally Posted by NckT View Post
    Well done!

    I'd still look into that fuel pressure again now the engine is running etc to make sure all is within spec etc
    yea, i probably need to. i left the fuel pressure gauge on after i got it to idle, and the at rest/off PSI was around 40; it held there basically indefinitely once the engine was off.

  7. #47
    Senior Member
    Join Date:  Mar 2016

    Posts:    182

    Reporting back after further shakedown. Here's where I'm at:

    -fuel pressure= ~40 at rest, ~65 at run, and stable.
    -dwell looks solid right around 40-42 degrees.

    the only strange thing i'm seeing is this: I took it out for a 30 minute shakedown. the idle was solidly in the 750-ish range, EXCEPT for about a 2 minute period in which it was goosed to about 3000RPM. I'd never seen it pegged this high. It gets stranger-it went away after about 2 minutes, and went back to 750-ish for the rest of the trip. To recap, new CPR, new thermister, new gaskets, new fuel lines. My hunch here is something physically sticking in the throttle linkage somewhere, intermittently. I don't really know where else to check, other than right at the spindle. The spindle, and the bar that links off of it, seem to operate normally; I can manually check the throw of it when it's running, and it gooses the RPM's. Any ideas? Where do I physically check for any possible throttle cable stickiness? Thanks!

  8. #48
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,000

    My VIN:    03572

    Quote Originally Posted by rjd2 View Post
    Reporting back after further shakedown. Here's where I'm at:

    -fuel pressure= ~40 at rest, ~65 at run, and stable.
    -dwell looks solid right around 40-42 degrees.

    the only strange thing i'm seeing is this: I took it out for a 30 minute shakedown. the idle was solidly in the 750-ish range, EXCEPT for about a 2 minute period in which it was goosed to about 3000RPM. I'd never seen it pegged this high. It gets stranger-it went away after about 2 minutes, and went back to 750-ish for the rest of the trip. To recap, new CPR, new thermister, new gaskets, new fuel lines. My hunch here is something physically sticking in the throttle linkage somewhere, intermittently. I don't really know where else to check, other than right at the spindle. The spindle, and the bar that links off of it, seem to operate normally; I can manually check the throw of it when it's running, and it gooses the RPM's. Any ideas? Where do I physically check for any possible throttle cable stickiness? Thanks!
    Fuel pressures look acceptable. You should have more primary pressure but that is not causing your problem.

    Dwell on a warmed up engine should be swinging back and forth pretty quickly about 30 to 40 degrees or more. If it's solid around 41 degrees something is wrong with the lambda circuit.

    You can set your throttle spool spring to the tighter selection. On my car where the throttle cable was clamped on the passenger side valve cover, that clamp had worn through the rubber cover on the cable and rusted the metal shield causing sticking. Also put some grease on that throttle spool spring and it's less sticky.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  9. #49
    Senior Member
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    8,570

    My VIN:    10757 1st place Concourse 1998

    Lubricate the throttle cable as per the recall. Take the throttle spool apart, clean up all of the old grease and relubricate it. If the quadrant link is very worn readjust it so it solidly pushes the throttle arm to idle. You will have more play in the throttle but you will always get back to idle. Tighten the spring as a last resort. Long drives with a heavy spring is hard on the feet. The system already has 3 springs in it and if it is working correctly they should be enough.
    David Teitelbaum

  10. #50
    Senior Member
    Join Date:  Mar 2016

    Posts:    182

    Further shakedown has been done over the last few weeks. Problem persists. Here's where it is, and what I've done:

    the problem: when the engine reaches a certain temperature, it will kick the idle VERY high. It usually pegs around 3k. I've done 4 shakedown drives now, and it always does it about 10-12 minutes in. I let the car idle in my driveway for the same period of time, and it did not go high. I have had the problem alleviated 2 times; once, it stayed high for a few minutes, and then came down on it's on mid-drive(I did not turn the engine off). The 2nd time, I stopped the car>shut the engine off>inspected the spool>restarted it-the idle went back to normal(with a wider hunt than I'd expect, but still averaging ~750-ish).

    Per you guys' advice, I went over the spool, and the cable, lubricating the cable, and tightening the spool. It seems to have no corrosion, and we've checked its' motion visually-the spool and cable are almost surely working properly.

    Any ideas where to check next? O2 sensor? ECU unit? I'm kind of at a loss. (Not sure if this is helpful, but the engine bay seems to get fairly hot after a 10-15 minute drive; hotter than I'd expect.) Thanks for the help!

Page 5 of 6 FirstFirst ... 3 4 5 6 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •