86 Vette Skip/miss problem
Thread Starter
7th Gear
Joined: Jan 2008
Posts: 7
Likes: 0
86 Vette Skip/miss problem
My buddys 86 vette (40k, 6spd, all original) has a skip/miss etc when getting on it under load (either wot or easing into it). The best way I can describe it is that it feels like wheel hop. The car still accelerates but it feels like its getting starved for fuel (its not, fuel pressure is good 34idle, 42wot, increases as he accelerates). I did a datalog yesterday and the O2 sensor was swinging as it should but it seemed to be too the extreme and was lit up in a red color in tuner pro. When this problem happens it pulls timing. We saw as much as 6 degrees yesterday.
No CEL
Any Ideas??
No CEL
Any Ideas??
Le Mans Master
Joined: Jul 2004
Posts: 6,228
Likes: 698
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
My buddys 86 vette (40k, 6spd, all original) has a skip/miss etc when getting on it under load (either wot or easing into it). The best way I can describe it is that it feels like wheel hop. The car still accelerates but it feels like its getting starved for fuel (its not, fuel pressure is good 34idle, 42wot, increases as he accelerates). I did a datalog yesterday and the O2 sensor was swinging as it should but it seemed to be too the extreme and was lit up in a red color in tuner pro. When this problem happens it pulls timing. We saw as much as 6 degrees yesterday.
No CEL
Any Ideas??
No CEL
Any Ideas??
Thread Starter
7th Gear
Joined: Jan 2008
Posts: 7
Likes: 0
Haven't pulled any yet, but was planning on it. I will update with results.
I was thinking, the miss is very consistent, almost its like a bad injector or something like that. I wonder if one of the injectors isn't spraying or not spraying much, that would make the other injectors compensate and screw up the o2 readings and pull timing correct?
Just spit balling here, I need to spend some more time checking things out.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I had a miss under acceleration a few years ago. It turned out to be a bad plug wire. I found it by looking at the running engine in a dark garage at night. #6 plug wire was arcing to the oil dipstick tube. When I pulled the boot off the spark plug it fell off the end of the cable.
Measure the resistance of all of the injectors. Anything less than 12 ohms is bad. Sometimes they read OK when cold but fail when hot so measure them when the engine is warmed up. It's quite common to find one that is very low compared to the others. If you find one or more that are low, don't go cheap and replace just the bad ones. The others are on the verge of failing.
Measure the resistance of all of the injectors. Anything less than 12 ohms is bad. Sometimes they read OK when cold but fail when hot so measure them when the engine is warmed up. It's quite common to find one that is very low compared to the others. If you find one or more that are low, don't go cheap and replace just the bad ones. The others are on the verge of failing.
