Noob with a question

[OldmanOlds]

I have a 1993 Olds Cutlass Convertible, 3.1, 4t60e 181k. I just tuned this thing up in Decemeber, and have developed a sporadic miss. It only occurs when the car is warm and only when under a load. There is no miss at idle, but when cruising at 55-60 there is no miss, but as soon as you crack some throttle to disengage the lockup it will miss like it is hitting the rev limiter.

I'm thinking this is the cat since I have been through the ignition just recently, and the miss is not constant.

Neither the cat or ex manifolds are cherry red after this occurs. Any opinions?

[5speedz34]

Have you touched the coilpack? If not it's probably them.

[NOHC_WBody]

Have you touched the coilpack? If not it's probably them.

 

+1 Check the plug wires & make sure they're still connected tightly to the coil packs and the plugs.

[OldmanOlds]

Well, it is not the cat as I removed it and straight piped it today. The miss is still intermittent and it is not blowing any codes. I am going to revisit the coils this afternoon, however, they have already been replaced a few months ago. Any other ideas?

[sl3196]

Pull the plugs back out. I had a similar problem and it was a cracked plug.

[Jeorge]

check the coils I had the same thing I had to replace my coils and IGN modual at the same time at 148xxx miles.

[DOHCRagtopguy]

I'd tend to agree with the coil/ignition module analysis.

 

(just my 2c)

[OldmanOlds]

Well....it's not the coils or the ignition module. I went to a salvage yard and bought a module/coil set and went through them with a digital multimeter. Coil posts are at 6K Ohms. Rears are at .55 Ohms. Everything checked out and was installed. Same problems exists. Still missing under load and no codes kicking off. Any other suggestions? Injectors, Oxygen sensor? Wouldn't an oxygen sensor kick a code of on the ECM?

[1990lumina]

Fuel pump?? Tired and old and can't keep up when kickin her down??

Wierd problem!

 

- Jeff L.