Car cutting out

[whitie2000]

My car has been having a wierd cutout feeling, any kind of help would be great.

Look between frames 6218 and 6325

[Perforator]

You got 9 degrees of knock at the start and your timing drops down to 2 degrees. That's probably what your feeling.

[whitie2000]

I see that but it only happens on certian days not every wide open run. Like on the wide open run before that there was no stutter. This just recently started, I will hit the gas and the car starts stuttering hard.

[CSC04]

You got 9 degrees of knock at the start and your timing drops down to 2 degrees. That's probably what your feeling.

Yes that is the OBVIOUS part of it.....
But how about the fueling? seems like it's going lean? but why?
The car did throw a misfire code. So we are going to replace all new plugs and wires and re-gap plugs.


There are multiple WOT runs in that hpl. and NONE with the same "PROBLEM" except for the one "whitie" says to look at. Like he says it will not "studder" every time just intermittently....? So this time we were able to duplicate the issue ONCE and who knows how long or when it will happen agian. It just comes and goes random....

Going to start a MAf tune to see if we can get the trims to lock in and go from there.

Does this osund like a good starting point?

[Perforator]

Sorry, I only looked where he told me too, I didn't study the whole scan. The studdering feeling is probably the timing. 2 degrees is bad. You need to find why your getting 9 degrees of knock. Could it be the downpipe hitting or something like that?

[CSC04]

Sorry, I only looked where he told me too, I didn't study the whole scan. The studdering feeling is probably the timing. 2 degrees is bad. You need to find why your getting 9 degrees of knock. Could it be the downpipe hitting or something like that?

Good call, we'll check some stuff out...
I guess a better question is..... Will a misfire cause the "symptoms" / problem that he described and that the scan showed?

[Perforator]

I've never heard of a misfire causing knock before. It will mess with your O2 readings. Don't remember if it reads lean or rich though.

[CSC04]

I've never heard of a misfire causing knock before. It will mess with your O2 readings. Don't remember if it reads lean or rich though.

TY.
We're going to do some of the things we listed previously and see if it helps...
In the meantime thx for the replies.

[e85grandprix]

ok first off stop flooring it until you add fuel. 890's is lean enough to blow a nice little hole in your piston. Tell me you aren't relying on your stock nb to tune your car?! The spikes you see where the timing is going down to nothing is the torque management keeping you from destroying the trans that's completely normal. I would go to the next sized pulley UP not down and start tuning the car correctly. Get it at the correct fueling with a wide band (if its not in your budget then don't even bother tuning) get the timing up to 20* knock free which should be easy with the i/c. Then start dropping sizes, but if you can't get 11.7afr and 20* of timing completely kr free then go back to the pulley you could do that with. The pulley's don't make the hp the timing does, and i'm not sure what pulley you were running with that scan but its to small for starters and you'll end up blowing a piston trying to tune with it. Use one of your bigger ones to tune with so you don't hurt the motor. Add fuel with the pe mode afr vs tps and to get richer you lower the number start with .5 from 70-100 and go form there AFTER you get a wide band, until then stop getting on it.

[e85grandprix]

I've never heard of a misfire causing knock before. It will mess with your O2 readings. Don't remember if it reads lean or rich though.

If its misfiring aka not firing at the right time (while the piston is going up for instance) then that would be considered knock. I had a plug wire ground out on me and fire the wrong cylinder and yea it was knocking for real and the sensors were spiking to 15 for a split second, and that what just cruising all the sudden knock knock knock uhhh ohhh...

[PDXGTP]

it sounds to me like a missfire, you know...

bad plug wire = most likely
Bad plug = possible if they are autolite's. When they die you can get a code for three way cat low efficiancy because of the unburned gas.
bad coil ... swap the coil with another, does the missfire change cylinders?
or .. how's the oil pressure? If oil pressure is fine, stay on topic above.
During the missfire, is the SES light on the dash blinking?
Trouble shoot it Mr...

[Perforator]

If its misfiring aka not firing at the right time

I wouldn't consider that a misfire, that's firing out of sequence.

[whitie2000]

I will be changing the spark plugs and wires tonight. The fuel filter and fuel pump were just changed. The problem is that this just started out of the blue the car had been running fine. I thought it was the dying fuel pump at first. I did get a misfire code but it did not say which cylinder.