89 won't restart, weak noid light
Thread Starter
Instructor
Joined: Apr 2003
Posts: 197
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89 won't restart, weak noid light
My 89 will start fine but when you shut it off, won't restart for a few hours. The car cranks fine so its not the starter. There is spark and fuel. When a noid light is placed on the injector its a weak light.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Check the resistance of your injectors both hot and cold. The readings on all eight injectors should be very close to each other and between 16 to 17 ohms while hot or cold. Your (and my year) year car has a high failure rate on the stock injectors. When an injector shorts out the resistance drops and that injector will draw higher current. Let me know if you need more info on this.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
I agree with ohming the injectors...but what would cause a weak light on the noid light...since you do that on the injector pigtail, while disconnected from the injectors...better check connections too.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
So the injector pulses are good when the engine is cold and weak when the engine is hot. You have confirmed there is fuel pressure and spark are good at this point. Have you pulled some spark plugs to see if they are gas soaked? Also have you seen if the injectors are leaking? The distrubitor sends reference pulses to the ECM, then the ECM calculates these and sends injector pulses to the injectors by grounding them. They are batch fire in the L98, so one side recieves signal at a time. May want to have the ignition control module check out.
Thread Starter
Instructor
Joined: Apr 2003
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The ICM was tested. It was having another problem so its been replaced but problem still exist. Having injectors tested like Sam Lam suggested. Looking at having stock injectors replaced with Bosch since the stock are a POS and will eventually fail.
Thinking electrical (short) since the noid light is weak on attempted restart
Thinking electrical (short) since the noid light is weak on attempted restart
Thread Starter
Instructor
Joined: Apr 2003
Posts: 197
Likes: 0
One injector in each bank is bad. With the bad ones disconnected the engine restarted with no problem.
Having all 8 replaced with "Standard" mfg injectors.
GM wonders why its going bankrupt. Designes a decent product but then buys the cheapest components.
Thanks for the help, my mechanic was scratching his head.
Having all 8 replaced with "Standard" mfg injectors.
GM wonders why its going bankrupt. Designes a decent product but then buys the cheapest components.
Thanks for the help, my mechanic was scratching his head.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Help us understand "one injector in each bank was bad"! What were the ohm readings on the "bad" injectors? You may also have other problems too......so be careful and do not place "all" your problems on the injectors. Just some wisdom from the school of hard knocks 
Also, suggest you use 22 pound replacement injectors.
Also, suggest you use 22 pound replacement injectors.
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Thread Starter
Instructor
Joined: Apr 2003
Posts: 197
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Don't have the ohms reading from my mechanic. There was an unrelated problem with the ICM when it was tested.
And I was advised to stay with 22# injectors since an increase without any other upgrades would cause problems with the O2 sensor sending conflicting info to the ECM.
And I was advised to stay with 22# injectors since an increase without any other upgrades would cause problems with the O2 sensor sending conflicting info to the ECM.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by seenalot
Don't have the ohms reading from my mechanic. There was an unrelated problem with the ICM when it was tested.
And I was advised to stay with 22# injectors since an increase without any other upgrades would cause problems with the O2 sensor sending conflicting info to the ECM.
And I was advised to stay with 22# injectors since an increase without any other upgrades would cause problems with the O2 sensor sending conflicting info to the ECM.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
The things you "learn the hard way" tend to be those you remember best
I learned about the Multec injector issue in this manner! This forum is the best in that we all learn from each other.
