hesitate/stumble

[sglfladad]

I'm going to do my best to describe a problem (I think) I'm having.
01 ZO6 - stock 80k miles.
Generally runs fine and fast. Once in a while only when wot from stop in 1st gear, as I get close to shifting into 2nd, engine bogs down and I feel something like a stumble or hesitation. Symptom continues for a little bit, even into 2nd. Continues even after letting up on the throttle..for just little bit, then all seems to go back to normal. Sometimes it has happened when wot from rolling start in 2nd and into 3rd.

Now, I read somewhere there's a rev limiter ...could this be kicking in and it takes the computer just a little bit to settle down again? Once I was watching the tach when it happened and I don't remember seeing it go past redline..but alot was going on and I'm not absolutely positive.

It feels similar to a feeling I had on another car when there was some gunk in the fuel filter and when fuel being sucked in it would clog, then unclog when backing off.

No codes in the DIC..

Is this normal, or could there be a fuel delivery issue and how would I diagnose that.

Again, it doesn't happen all the time.

Thanks for any advice.

[Rich Z]

Yeah, sounds like the rev limiter to me. First couple times I hit it I thought the same thing. My C5Z is the first car to ever have some sort of device like that. Well at least in a case where I would actually ever hit those high rpms.

I believe that hitting the rev limiter shuts off the fuel supply, so that is exactly the effect you would get.

Try keeping your eye on your tachometer to see if you are red-lining it when that problem shows up.

[gmjunkie]

It's probly time for a Sea-Foam treatment!!!!!!It's got gook in the Throttle Body and Injectors!!!

[sglfladad]

ahhh... the old operator error issue. I was afraid someone would say that

Seafoam treatment? Google here I come.

[gmjunkie]

Originally Posted by sglfladad

ahhh... the old operator error issue. I was afraid someone would say that

Seafoam treatment? Google here I come.

CLICK!!

[sglfladad]

Originally Posted by Krazy Horse

CLICK!!

Great!
1 question. The post says "remove the tube from the other side of the PCV valve" duh...ok i'm a dummy, but ummm the other side from what?
1 side goes to the valley cover and the other goes to the intake manifold. Which side to I remove the tube from and let suck up the seafoam..my assumption is that it should suck into the intake manifold..I just want some clarification on that before I do it. And I don't want it to suck through the pcv valve, right? Got the seafoam here waiting to do it's job.

Rich is probably right about operator error...rev limiter..but 80k miles..no service record when I purchased it..so most likely the seafoam is a good idea also.

[gmjunkie]

Originally Posted by sglfladad

Great!
1 question. The post says "remove the tube from the other side of the PCV valve" duh...ok i'm a dummy, but ummm the other side from what?
1 side goes to the valley cover and the other goes to the intake manifold. Which side to I remove the tube from and let suck up the seafoam..my assumption is that it should suck into the intake manifold..I just want some clarification on that before I do it. And I don't want it to suck through the pcv valve, right? Got the seafoam here waiting to do it's job.

Rich is probably right about operator error...rev limiter..but 80k miles..no service record when I purchased it..so most likely the seafoam is a good idea also.

Yes let it suck through the PCV into the throttle body it will clean it too!!

[sglfladad]

ok..did the seafoam thing. I little smoke, but not much. Went out for a "sprited" drive. Maybe imagination, but seems smoother, stronger.

1st gear..right to redline, no problem a couple of times.

1st gear, to about 6k and the symptom occured. I'll try to write down what and when happening...maybe see a pattern.

Any thoughts?

[gmjunkie]

Originally Posted by sglfladad

ok..did the seafoam thing. I little smoke, but not much. Went out for a "sprited" drive. Maybe imagination, but seems smoother, stronger.

1st gear..right to redline, no problem a couple of times.

1st gear, to about 6k and the symptom occured. I'll try to write down what and when happening...maybe see a pattern.

Any thoughts?

Did you put 1/2 the can in your gas tank??It needs to have 1/2 the can run through with about 10 +/- gal of gas thats the only way it can clean the Injectors! PS the rev Limiter is supposed to come in at between 6550-6700 +/-on a Z06 and 6050-6200 +/- on a LS1!! If it's gook-ed up purdy good you may have to do it again in a week or so,I had to on mine and it only had 39,000 mi. on it!!

[sgsvette]

Sounds like the fuel filter is clogged. When was the last time you changed it?
Very easy and inexpensive fix. Have seen same symptoms before and it's been the fuel filter.