696redZ-28

How can I figure out a miss-stumble happens only 4500-6400rpm
feels like spark miss lasts long enough to feel like I'm feathering the throttle
happens more in higher gears when load is higher;
is not always there;
I installed Delteq so it's not the opti!;
Have irudium plugs taylor wires both have 4500 miles on them;
I also have an Auto x-ray scanner but can't seem to catch miss and I need help at what items to look at;
any help wold be greatly appreciated!

BamaZ28

Always check the easy things first, loose wires on the coil OR plugs. Check for burnt wires, vacuum hoses (can't remember if the LT1 has many). Tight plugs.....I had a miss once and it ended up being a loose plug.

696redZ-28

not the coils they are new, still have same miss that I had with one coil. wires are mostly same but with new 90 degree ends plugs I will test next weekend!

fesgali

I'm having the same prob when i floor it, it happens around the 4,500-5,300 rpm range. The engine starts to pop/bang, and the rpm does alot of movement, if it's in 2nd (right before it shifts out) it'll start to do it and then after a few seconds of stalling it'll shift. Then i figured out it also does it in first gear more around the 4,500 rpm range. But the funky thing is that i can rev the car up to about 6,000 rpm with no problem in N or P and keep it there for a few seconds with no problem. But i'm leaving for vacation for 2 1/2 weeks and gonna play with it when i get back.

kingman109

mine was acting simular- changed fuel filter- car feels like it has an extra 60 horse and has been fine since - guess it was being starved


start with simple things

SkillZ25

I see you have Jet hots....dont the stock Knock moduals mess up when it gets too loud? (Correct me if im wrong) I think thats why people upgrade their KM's.

696redZ-28

I chaned the knock sensor and module in computer to help with headers; my scanner shows some I think 4 degrees of knock retard is that too much?

TobyZ28

Fuel pressure, or a kink in the fuel line?
The increase of it happening when there is load would lean me towards a fuel issue...

TobyZ28

Did you figure this out? Mines doing the same thing now, my fuel pressure checked out tottaly fine at WOT (Taped it to windshield 44 PSI Steady)...