Bad ignition or what?

[BJM]

My car drives fine, it just has what I would call a weak idle. It seems to miss randomly about every 10 seconds, very occasionally stalls.

I had this once before, it was a coil going bad. I have a Type II ignition I got from a junk yard with unknown miles and it has worked great for about a year. It still drives fine. I checked the secondary side of the coils and they are 6-8 kiloOhms each which seems good to me.

I bought a brand new module and I see almost no change.

The ignition wires are AC Delcos 1 year old and the plugs are 1 year old as well and that is about 6000 miles ago.

Not sure what to look at next. Could the coils be bad on the primary side, its hard to check them because there are sockets on the bottom instead of tabs like the Type I.

Any ideas appreciated.

 

[bruce]

Try running the engine in absolute dark, and look for any sparks not going where they're not supposed to be.
A plant mister is also a good way of wetting down the wires one by one looking for an errant spark.

Might try closing the gap up some on the plugs, and see if that changes anything.

Might do alot of DS datalogging looking for a faulty MAF.

 

[Sleeper]

FWIW
Check your harmonic balancer for looseness, and look at your crank sensor alignment as well. I had a similar problem, and after doing the coil pack check, and finding nothing wrong, it ended up that the bolt had come loose on my harmonic balancer, and the balancer had built up some play in the key-way, enough to cause a intermittent miss.

Paul

 

[BJM]

I guess I posted this in the wrong forum, oops.

I swapped plugs, the old ones looked fine, barely used in fact.

New plugs, no difference. I tried the darkness thing, I couldn't see anything at all.

I tried some light misting of the general upper engine area, nothing changed.

This is all with the MAF in the up pipe and I don't really like the way the pipe adapter squishes after the MAF. Also my idle BLM wanders around continually, its crazy. It can wander anywhere from 121-145. Usually it moves 6-10 or more at every stop light and tries to stumble, occasionally nearly stalling. For some reason it takes upwards of a minute for the car to enter open loop idle.

I think I better try putting the MAF back in the normal position.

I might still have a bad coil though.

I gave a tug at the balancer but not a good looking over yet.