Tbi runs strange

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Honky Kong jr

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I checked the plug wires. All look good. No holes in them. The fuse that blew was ecm 1


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Well if you need an ECM let me know. I have the one from the 87 which worked and one from the 89 which is an AC Delco reman.
 

87silveradok20

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I got the truck running again. It ended up being the plug for my egr fell down and was laying on the exhaust manifold causing the egr plug to short out. I still am having the problem with the truck stumbling tho. I got a fuel filter and am gonna give that a shot


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1987 GMC Jimmy

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That’s interesting. Glad it ended up being something non-invasive. Keep us posted.
 

87silveradok20

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Fuel filter wasn’t the problem took it for a drive and it’s still not running right. It sounds like it might be beck firing thru the intake.


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Billy

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I had a similar problem and it was the ecm ground . It's grounded with the cts
 

mikedgarage

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Well if you need an ECM let me know. I have the one from the 87 which worked and one from the 89 which is an AC Delco reman.

If you use an ‘87 ECM in make sure you use the ‘87 knock sensor. They changed it fo’89 and up.
 

87silveradok20

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If you use an ‘87 ECM in make sure you use the ‘87 knock sensor. They changed it fo’89 and up.
The ecm number was the same on both trucks. Do I still need to switch the knock sensor


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mikedgarage

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You may not need to if the Part numbers are the same. It could be a late '87 ECM, after the change.
 

Dan Brown

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Check the Idle Air Control motor. Sometimes they'll act up and not set a code. Take it out a clean the plunger and passages and see if that helps.
 

DBurns007

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Hi..

I would take a really close look at your throttle body gasket and ignition..Primary and secondary. Start the truck, let it warm up and bump a little carb spray at the throttle body gasket... listening for idle up witch would indicate a vacuum leak. Also would explain misfire and erratic idle... remember, carb spay is flammable. So.. actually. Disregard. I would say check all of your secondary ignition. Plugs, wires, cap and rotor..

And just change the throttle body gasket. I’ve seen the throttle body gasket cause your symptoms many times.

Have a look at it..

Also.. check vac. Leaks at the blocked off EGR.

Shoot us a pic of the engine if you can..

Assuming you still have the truck?


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