Search results

  1. G

    Weird idol and no power when driving

    Put a vacuum gauge on the EGR solenoid port on the TBI. The solenoid shouldn't be trying to open at idle. Use a mighty vac to make sure lines aren't leaking and are holding vacuum. You can also measure voltage at the MAP sensor or use the aforementioned OBD1 cable and app to watch MAP values...
  2. G

    Weird idol and no power when driving

    All you need is an OBD1 blue tooth cable and thr ALDLDroid app on a phone or tablet to see what the computer seems from the sensors. Plus fuel trims, knock counts, etc. All in your looking around $100 or a little more. With the losing power on hills comment, I am guessing large vacuum leak...
  3. G

    Weird idol and no power when driving

    could be a big vac leak and the clicking sound is the stepper motor on the IAC bottoming out at 0 IAC counts and all the way closed. is it idling high?
  4. G

    S-10 2.8 TBI runs rough midway through warmup

    good point. stick to ac delco for all the sensors. even then, it's no guarantee...
  5. G

    Possessed Power Door Locks on '90 Burb

    the GM wiring diagrams, along with owners manuals, repair manuals, and service manuals, are in the reference library of this site
  6. G

    S-10 2.8 TBI runs rough midway through warmup

    it could also be the IAC hanging up if it is only midway in the idle down process?
  7. G

    Possessed Power Door Locks on '90 Burb

    I think the relay is by the fuse panel. does it ever do weird things when you use the windows? I had a strange issue one time with locks and windows and it was a mouse chewed harness under the dash. that's the only place the harness for those two things runs together. is there any aftermarket...
  8. G

    1987 350 TBI and 1990s 350 TBI interchangeable?

    I'm guessing very similar computer and sensors. 1990 has a serpentine belt setup.
  9. G

    Almost met Jesus this AM due to a faulty thermostat!

    not sure why the engine died, but definitely seems like the thermostat is stuck partially open.
  10. G

    tow rating - '90 2500 Suburban

    in the owners manual?
  11. G

    87 350 TBI running lean

    I'd first try to reset the IAC. jumper A and B on the ALDL and turn key to on for about 45-60 sec. that will force it all the way closed and the computer will know where 0 counts is. turn key to off, remove jumper, and start it and see how it does. if that doesn't help - are you on a stock...
  12. G

    87 350 TBI running lean

    if you are monitoring sensors, IAC counts at 0 would definitely point to a vacuum leak. do the IAC counts jump when you put it in park, and then come back down? BLM and INT at 128 is "perfect." higher is adding fuel and lower is taking away fuel. BLM would have to be up near 150 to be really...
  13. G

    1987 350 TBI code 42

    in the reference library of this site. it was the drivability and emissions manual, or really the TBI user manual. there are also repair and service manuals and also owners manuals and wiring manuals by year. they are .pdf and word searchable. an invaluable reference for free!
  14. G

    1987 350 TBI code 42

    I love an easy fix!
  15. G

    1987 350 TBI code 42

    hard to imagine its running well with code 42 set. this should help diagnose. if it isn't the ignition control module and the EST wire is plugged in, I'd expect to have to carefully evaluate the ICM and coil connectors and wires to look for the issue. a quick check on the EST wire would be to...
  16. G

    Options for tuning of Gen1 TBI in 2023

    I use my phone with ALDLDroid and a Bluetooth OBD1 connector. you can export the csv files to your email and open in excel and save as an excel file.
  17. G

    1986 gmc sierra classic c2500 aldl location

    not sure about the earlier years, but on my 1990 it is below the dash to the right of the e brake release
  18. G

    Options for tuning of Gen1 TBI in 2023

    I was just logging with ALDLDroid, which isn't as capable as other software.
  19. G

    Code thrown but not for my year/MAP issue

    ECM can't tell of the cat is clogged. I had a miss at idle and under low vac/low RPM situations. it went away after I replaced my exhaust system. it was driving me nuts. I can only assume it was the cat....
  20. G

    Code thrown but not for my year/MAP issue

    if the code 34 is intermittent, check the vacuum lines again and wiggle the harness around and see if you can get it to throw the code again. take the sensor out of the bracket and move/twist it to manipulate the harness. you might also consider running some ac delco top end engine cleaner...
  21. G

    Code 24, when going down hill.

    loss of VSS signal indicates a wire may be broken or mostly broken and going down hill moves it just right so it loses connection. I'd be looking at the harness to the VSS running alongside the transmission and/or transfer case as the most likely spot for an issue like that. just fyi - I had...
  22. G

    Lacking power, 87 Sierra 5.7l TBI

    if the tach is jumping around even though the engine seems to be at constant RPM, there could be extra references from a poor distributor (ICM) ground or interference from the plug wires being too close to distributor/coil wires.
  23. G

    Glove Box Latch 73-87 (91) Chevy GMC Trucks

    it's been a year or so since I've ordered from them, but I never had any issues with LMC across more than a dozen orders.
  24. G

    New TBI injectors causing surging

    are you running a stock engine and stock PROM chip? if not, maybe somebody has modded the engine and has tuned the PROM chip and installed different flow rate injectors. are there any numbers to compare on the old injectors to new injectors?
  25. G

    New TBI injectors causing surging

    save the money on throwing parts at it and use it to get ALDLDroid and a Bluetooth OBD1 cable to diagnose. it will save money on parts in the long run.

Latest posts

Forum statistics

Threads
44,164
Posts
950,695
Members
36,277
Latest member
chevyBlu
Top