Hi guys,

I have got a 2001 Z28 and just had a new enigne put in it a year aso. Everything was fine at first but now the engine misses on acceleration. I talked to someone who used to work for a pontiac dealer says it might be a coil thats behind the water cooler. Can some one give me a little more info on this before I show up at the dealer not knowing what I am talking about.

Not meaning to be blunt - but, you already do sound 'like you don't know what you're talking about' - because you and "we" don't yet...
Your discription would tell us (or the dealer) little and certainly not enough - so far - to know what to 'fix' to cure the problem.

Several systems could be causing the issue. Could be an electrical issue, something as simple as a bad plug or wire or something more involved such as a sensor. Could be from the fuel delivery system. Again, something as simple as the filter being dirty or as involved as bad injector(s) or pressure delivery and regulation issues.
Since most of these repairs involve knowledge of the systems and subsystems, they are beyond the level of most 'driveway' mechanics - except for maybe changing the fuel filter and seeing if it helps. But, even this can require a couple special tools...

It's best to take the car to a good dealer or mechanic and let them diagnose the problem - you're 'knowledge' can at times lead them off on wild-goose chases that just waste their time and your money...
Or take the time to become knowledgable about your car and it's systems by reading and studing the systems as the mechanics have and then you can talk-the-talk with them and help them find the problem.

Hope this helps...

Ok, after a little research to be able to explain to the dealer what was happenning with my car, I found the problem that I have been chasing for almost 2 years and it turned out to be a part that cost just over $200. And here it is.....

The Mass Air Flow Sensor

DIAGNOSIS
An engine with a bad MAF sensor may be
hard to start or stall after starting. It may
hesitate under load, surge, idle rough or run
excessively rich or lean. The engine may
also hiccup when the throttle suddenly
changes position.

If you suspect a MAF sensor problem, scan
for any fault codes. A MAF problem should
(but does not always) set a fault code.
Codes that may indicate a problem with
the sensor include:

GM: Code 33 (too high frequency) and
Code 34 (too low frequency) on engines with
multiport fuel injection only, and Code 36
on 5.0L and 5.7L engines that use the Bosch
hot-wire MAF, if the burn-off cycle after
shut-down fails to occur.

Ford: Code 26 (MAF out of range), Code
56 (MAF output too high), Code 66 (MAF
output too low), and Code 76 (no MAF
change during “goose” test).

Of course, don’t overlook the basics, such
as low engine compression, low vacuum,
low fuel pressure, leaky or dirty injectors,
ignition misfire, excessive backpressure
(plugged converter), etc., since problems
in any of these areas can produce similar
driveability symptoms.

I hope this helps anyone else who is having the same problem I had. What’s strange about it is some of what I was explaining to the dealer is in the diagnosis paragraph and they seemed to be just as confused as I was on how to get my car to stop missing. Before they came to this latest conclusion they put in new plus, ignition wires and a new catalytic converter. All of which didn’t help the problem. Anyway my car now runs great and I can now move on to do other things to it that I have been waiting to do for a long time.

I find it hard to belive that the ECM did not store the trouble code for the MAF sensor. I had the same problem, but it was intermittent. The check engine light would come on usually after filling up the tank with regular unleaded. I scaned the computer and the code popped up (33 or 34). I replaced the MAF sensor and the car is running good ever since then....even on regular unleaded which is the correct gas for the car.