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88 Chevy Check Engine Light On All The Time.

HotdogMB

By HotdogMB
in Ask A GM Technician

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HotdogMB Enthusiast

HotdogMB

Posted
Posted

also has fast idle and won't let me read the codes. Battery is fully charged and charging system is at 14.1 volts. Could this be a bad ground somewhere or something else?? I have changed the TPS as this is what it was last time. It only has 398,000klms on it so what could it be??LOL

txab Senior Enthusiast

txab

Posted
Posted

Maybe the carb linkages need to be cleaned. That's one place to check if you haven't already

HotdogMB Enthusiast

HotdogMB

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Maybe the carb linkages need to be cleaned. That's one place to check if you haven't already
EFI, and cable is good with no tension.

 

Any help would be great.
txab Senior Enthusiast

txab

Posted
Posted
Maybe the carb linkages need to be cleaned. That's one place to check if you haven't already
EFI, and cable is good with no tension.

 

 

 

Actually I meant the throttle body and the plates. I wonder if they might be carboned up and hanging up and not closing. Also check your idle air selenoid

bill190 Enthusiast

bill190

Posted
Posted

I don't know how you are trying to read the codes?

 

If by the ALDL jumper method, it is possible this is not being done right.

 

Also it is possible the engine computer is toast.

 

Or wiring problem to ALDL connector. Bad terminal, etc.

 

Pretty much you would need to follow the troubleshooting instructions for testing the engine computer and ALDL test connector which would be in a GM Factory Service Manual set. (Order from helminc.com or a GM dealer.)

 

Also it is possible there is a problem with the wiring to the light itself (remote chance, but possible.) And the factory manual would list all situations where the light would stay on steady.

 

Also if you can, might want to take your vehicle to local auto parts store (Autozone?) and see if they can read your codes with their reader.

  • 2 weeks later...
HotdogMB Enthusiast

HotdogMB

Posted
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Hooked up the wires, the right way, as per the repair manual, and the light will not flash. It just stayes on all the time. I have changed the TPS and IAC with no good results. Seems like there is no power to the IAC because the plunger doesn't move with the key on. Is my ECU shot or what?? I by passed the fusable link in the power wire as well. Please help!! This is my hunting truck!!

bossier62guy Senior Enthusiast

bossier62guy

Posted
Posted
Hooked up the wires, the right way, as per the repair manual, and the light will not flash. It just stayes on all the time. I have changed the TPS and IAC with no good results. Seems like there is no power to the IAC because the plunger doesn't move with the key on. Is my ECU shot or what?? I by passed the fusable link in the power wire as well. Please help!! This is my hunting truck!!

 

How about telling us just what you did exactly to try and get the codes....w/o them it's going to hard to figure out what's going on....

HotdogMB Enthusiast

HotdogMB

Posted
  • Author
Posted

I grounded the dignostic terminal, as per my repair manual, and turned the key on. No, flashes nothin. Light just stayes on. I have checked for codes in the past and it fashed codes then.

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