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  1. G

    700R4 TCC Lockup Issues

    The service manuals are in the Reference Library of the forum
  2. G

    Vince's TBI woes, progressive revelations, and tbi mods.

    The IAC counts seem normal. Some folks like them on the low end to have more air through the throttle blades for better fuel delivery. IAC opens up when you are off idle. Mine are normally in the 90-100 range when cruising, and 120ish range with AC on. So blipping the throttle will open IAC. But...
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    700R4 TCC Lockup Issues

    I had a cracked TCC solenoid on my 1990 and it caused partial locking and unlocking. but on my 1990, I could use a scantool to check if the computer was commanding lockup and check to make sure the brake switch was working properly at the ALDL. guessing that your '86 might not have those options...
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    Vince's TBI woes, progressive revelations, and tbi mods.

    there is some sort of a stall-saver mode that will open the IAC to let in more air to bump idle. I don't know a lot about it, though. it kicks in when RPM drops below a certain target is my guess. the AC also affects IAC position. it opens up more when the compressor kicks on. when the idle...
  5. G

    Vince's TBI woes, progressive revelations, and tbi mods.

    you said the fuel pump and filter are new, but have you checked the fuel pressure? ideally with a gauge long enough to watch while you drive? or will it idle bad just in the driveway and you don't need to drive it to act up? or a vacuum leak that is worse under load...something like an intake...
  6. G

    1987 TBI fuel pump issue

    also check the fuel pressure on that pump....
  7. G

    Fluid Changes

    I am assuming I can clean them with a pipe cleaner or one of those stiff brushes meant to clean out straws if the crud isn't too hard?
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    Fluid Changes

    Nope, but that's on my list of things to check....I suspect I may have a combination of slow drain back holes and bad seals. Maybe worth popping off the driver side cover and investigating. I think it comes off without having to get any accessories out of the way...
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    Fluid Changes

    Not in consumption, because I lose all my oil through the valve stem seals :). I switched bc the oil pressure at hot idle was a little low compared to a few years ago. Used to idle around 28-30psi and was idling at 20-22psi this summer. After a couple oil change intervals, it does seem to be...
  10. G

    Fluid Changes

    That's what I started running a couple changes ago. I will say the oil comes out DIRTY at 3k miles.....it must be doing something
  11. G

    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    surprised it would run on fluid if ecmb has no power at the fuse panel? ecmb powers the ecm and the fuel pump, that's it. Orange wire in the harness, goes to ECM and fuel pump relay and splices into the oil pressure switch for a backup to the fuel pump relay. if the fuel pump is running, but...
  12. G

    1987 Silverado fuel issue

    87 might be different. My 90 burb has the oil pressure switch and the pressure reading for the gauge all in one behind the distributor.
  13. G

    1995 S10 est wire location?

    https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/timing-disable-wire-connection-84209/
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    1995 S10 est wire location?

    Didn't they move that inside the cab, maybe under the dash or behind the glove box, in the later TBIs?
  15. G

    Something killing battery

    it might be hooked to constant power instead of ignition power....
  16. G

    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    if it is the original cluster and the wiring hasn't been hacked to pieces there is a check engine light. on my 1990, it is bottom right on speedometer i think. it could be different on yours. use Chart A1 to diagnose the lack of a check engine light. it could be a bad bulb or maybe a PO got...
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    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    right here on this website! https://www.gmsquarebody.com/threads/1973-1991-service-manuals.14499/
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    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    I'd run through the diagnostics to be sure (i think you need chart A4 from the emissions and drivability manual). but my money is still on the ICM being bad.
  19. G

    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    I believe it is the reverse - 400rpm and below the ICM is controling the timing and above 400rpm the ECM is controling the timing.
  20. G

    ‘87 454 TBI, NO Fuel spray, HAS fuel pressure, has 12v @ injectors, has spark

    agree - you could run through the diagnostics, but it sure sounds like the ICM based on having spark and fuel pressure.
  21. G

    GMT400 wipers not returning to rest

    unless something is loose in the linkage, it is likely a park switch problem. not sure how they are set up on that style. but I bet it is somehow integral to the motor.
  22. G

    O2 Sensor Testing

    As far as I know PROMs are engine specific. Might be close enough to run, but certainly not as well as if the PROM is correct for the engine. TBI can only compensate so much also depends on if the injectors were swapped to 350 injectors, or if the 305 injectors were used. if a 350 was...
  23. G

    O2 Sensor Testing

    did you put in the correct PROM for the new engine in the ECM? if not. I'd start there. going from 305 to 350 and not changing thr PROM could cause all sorts of issues.
  24. G

    Bulb with black plastic wire

    might be for the HVAC controls if it has a bulb attached and doesn't have a spot in the cluster.
  25. G

    Intermittent wipers

    the intermittent is controlled by a pulse module that plugs into either side of the wiper harness at the base of the steering column. not sure if this can be readily added, depends on how PO modified the switch location. not parking sounds like a park switch issue in the motor itself.

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