Misfire - hesitation
05-04-2009, 12:24 PM
#31
Rennlist Member
This is a bit off topic, but my son's 89 corvette, 5.7 Liter, has "exactly" the same problem at 1900 rpm. Above and below no problem, under acceleration, apparently no problem, just a relatively steady 1900 rpm, it hesitates, and seems to be missing. We just replaced the oem injectors - total crap, I understand - but it still has the problem. We've done ignition, plugs, wires and no change. I guess the O2 sensor is next, but it's frustrating.
I'll watch this thread for suggestions since it's exactly the same symptoms.
Rod
I'll watch this thread for suggestions since it's exactly the same symptoms.
Rod
05-04-2009, 01:22 PM
#32
Three Wheelin'
Thread Starter
did you run the engine in the dark ?? Open the hood and run it .
Run the engine up to 2500 and look for sparking wires, especially along the coil wires they can sometimes leak along the side of the chassis.
Also look for leaks at the caps where the wires join . the wires should be 3 ohm.
...
Run the engine up to 2500 and look for sparking wires, especially along the coil wires they can sometimes leak along the side of the chassis.
Also look for leaks at the caps where the wires join . the wires should be 3 ohm.
...
Thanks
05-04-2009, 02:16 PM
#33
Three Wheelin'
Thread Starter
From the Bosch Website :
Insulator nose grayish-white or grayish-yellow to brown.
Engine is in order. Heat range of plug correct. Mixture
setting and ignition timing are correct, no misfiring,
cold-starting device functioning. No deposits from fuel
additives containing lead or from alloying constituents in
the engine oil. No overheating.
Insulator nose grayish-white or grayish-yellow to brown.
Engine is in order. Heat range of plug correct. Mixture
setting and ignition timing are correct, no misfiring,
cold-starting device functioning. No deposits from fuel
additives containing lead or from alloying constituents in
the engine oil. No overheating.
05-04-2009, 10:59 PM
#34
Three Wheelin'
Thread Starter
06-14-2009, 04:45 PM
#37
Three Wheelin'
Thread Starter
Got it 
. It was the ignition coils. The old one tested OK but they probably was not able to give enough spark.
Thanks all for your help.
. It was the ignition coils. The old one tested OK but they probably was not able to give enough spark.Thanks all for your help.
06-14-2009, 05:06 PM
#38
Administrator - "Tyson"
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Lifetime Rennlist
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06-14-2009, 05:13 PM
#39
Archive Gatekeeper
Rennlist Member
Rennlist Member
The PO of my GT had swapped out the coils in 2005, which cured a hesitation problem he was having.
06-14-2009, 10:25 PM
#40
Three Wheelin'
