Hi, I had this problem on and off, and its really kicking my ***.

I put in an MSD coil and an MSD dist. cap and rotor.
(This is the newest set up, I had two different caps and rotors)

Anyways, my problem comes after I idle in drive for about 10 secs. The RPM's would drop to 500 than slowly climb up and the car starts idling like it has a bigger cam.
From there the car has no umph from the stop and drivveability goes down the drain.
The car need some pedal to go good.
If I don't idle and keep on driving, or stop for a sec or two the car runs great!

The tranny shifts perfectly and its not slipping.
I have a new CTS, TPS, IAC, re-built the TBI, new coil, new distributor with cap and rotor, new fuel filter, new pluggs (but#8,10k on that one), new wires etc.

I really need some help, and I am stuck on an electrical problem.

This all happened when I replaced the coil and cap and rotor.
It took about 4-5 days after to get all messed up.
Please help, I am lost.

 

double check your base timing. I'm guessing your distributor holdown bolt was just lose enough that when you put the new rotor button and cap on it you *may* have moved it enough to cause the knock sensor to retard/ advance timing at certain pnts.

 

The hold down bolt is tight on there, with new distributor I put my base timing at 4 advanced, it was at around 8 with the Electoronic advance unplugged.
The air fuel ratio was really lean untill I messed with the idling screw, which got me a better response and the hissing that I had from IAC was gone.

Whenver, I change the cap and rotor and start the car, it will drive great for about 2 min. Than it starts again and the car gets sluggish around 10-30mph. I really have to mash it to get it downshifted just to go faster.

Somebody said fuel pump, but it sounds to me like something with igintion, although I have everything new on there (except starter)

One thing I found out was that my negative battery cable was loose on the block, and now my starting is a lot better.

I also have a header collector leak and its bad. Could this have something to do with the car.

A bit of rod knock, or spark knock, very hard to tell, only when I advance the timing.

Damn, this is killing me, ruining my third gen driving pleasure.

 

Can one bad sparkplugg make the motor run that bad???

Where is the coil getting power from, not totally sure?
How can I test the coil?

What does usually make the off idle drive sluggish??

Thanks.