Weird problem, Idle Performance etc.

[lndshark]

Ok heres what happened. Was leaving my store and there were a couple of guys sitting in the parking lot, and some kid inside had just asked me about my SHO. S6 figured Id give them a taste of my new flowmasters. So from maybe five miles an hour, I hit the street and got on it. Sounded very good. However, my ABS Sensor that gives the PCM its speed reading is on the fritz, so my speedo didnt move at all, and the tranny didnt shift. So, I realized this a few seconds after I should have felt a shift. I was darn near 7K if I didnt go over for a second or two.

Anyway, the way to fix this problem is to stop shut the car off, and upon restart 99 percent of the time it will be fine.

however, when i started my car this time, it souunded terrible, shaking idling down to 300 or so then flicking back up to 1500, sounded terrible. I drove the five miles to my parents house, and the car ran like crap, there was a deffinate hesitation when driving, the best way to describe it would be to say, it felt like i was driving and then the car lightly buck or something like that. I got freaked out but finally made it to my parents house. Cleared the computer, oh, scaned for codes first, nothing, and let the car sit for a hour and a half. I then hooked the battery back up. Upon restart the car sounded like crap again, however after five minutes of driving it seemed to smooth itself out. When I arrived home I let the car idle for thirty seconds and it was dead solid like before this incident.. Havent started it yet today.

What did I do? Could it be a coincidence that a coil pack started to go on the fritz at the same time as my idiotic display? I would appreciate any input

thanks brian

 

[ArkanSHO]

If you are talking about your '98, the speedo's on those things are crap anyway. The rev limiter would keep you from going over 7250 but you will feel it when it starts cutting out for that reason, kind of like revving it in park to 4k. Coil pack? The V8 has a coil for each cylinder. One coil will cause a miss that is perceptable, but certainly not one that will make your car run "rough" or "buck". Not likely that would clear itself up in any case. Sometimes the PCM will get a false reading off of some sensor and totally set the engine up for the false measurement (temp, air volume, throttle position), as you said you have cleared this by turning the car off and restarting. I would have the identical same issue when my SuperChip would lose contact momentarily with the PCM or if I accidently switched to another program while the car is running. I eventually went with Doug's tuner and haven't had that issue since. You don't have a hyper or Super Chip do you? Only other issue would be the fuel system. But that is not likely to clear itself on a power cycle. Faster way to clear the PCM codes by the way is to disconnect the battery then step on the brakes or turn on the headlights to drain power from capacitors inside the PCM that would retain the memory. It would take a few minutes after starting the car for it to reset itself for your driving style.

 

[lndshark]

Carter, thanks for the input. Man, I drool over you SHO every time it comes up on my screen saver, I have the Gen III one from v8sho.com. Sweet car.

I was thinking maybe fuel filter?? but doesnt make sense it would clear up. I dont know, didnt set any codes or anything.

The only thing I can think is that after I had my cams welded it developed a misfire in cylinder #8, according to the scanner. We had a long drive home, drove like crap the first fifteen miles then smoothed out. The next week or two the SES light would come on every other day or so. I cleared the codes two weeks ago and nothign new has popped up.

ran fine today, oh well. guess ill just take it easy from now on.

thanks brian

 

[Silvapain]

It's typical to have a COP go bad after a cam weld. You have to pull all the COPs off to get the valve covers off, and the physical shock of pulling them and putting them back on can cause an old COP to fail. Usually guy who weld cams will put the front bank COPs in the back after a weld - this is because the rear COPs fail much earlier due to the heat back there in the cramped space right above the exhaust manifold.

I had two new COPs put on the back bank when I had my cam weld done. within a month, the two original COPs in the rear bank went out and had to be replaced.

 

[ArkanSHO]

Carter, thanks for the input. Man, I drool over you SHO every time it comes up on my screen saver, I have the Gen III one from v8sho.com. Sweet car.
guess ill just take it easy from now on.
thanks brian

Thanks.
As for taking it easy, the only time I used to have problems with mine before I installed the blower was if I took it easy (other then collecting moving violations). I drive em like I stole it.