: Engine miss

11-28-06, 10:33 AM
I have just done a HG on my N*. Everything seems to be OK. The engine was out of balance, but I wouldn't call it missing when I first started driving it. Each time I drive it it seems to get better. The milage is 23.5. I put in new plugs. I looked at the front bank and if anything they are burning a little lean. I will ocassionally stumble at idle and when it is lugging on a hill. The tac will also occasionally jump around but there is no noticeable affect on the engine when the tac is irratic. Before the HG job the coil paks seemed to be making a clattering noise, that is gone now, the only differnce on the ignition side is new AC plugs. I'm sure the next logical move is plug wires and coil paks. Any advice on the how to diagnose this further.

11-28-06, 04:06 PM
Mist the wires in a dark place at night and look for a light show. I'd suspect the wires before coils, especially if they are original and the fuel rail recall has been done. Seems to be a common problem afterwards.

11-28-06, 06:49 PM
Also if you have a Multimeter you can check the wires for proper resistance, I believe its 15K OHms or similar.

11-29-06, 08:56 AM
The fuel rail was recently done. I had the codes read last night. Current codes are P0441,P1370,P1375 and P1376.

P0441 - Evaporative Emission Control System Incorrect Purge Flow
P1350 - Ignition Control System
P1375 - IC 24X Reference Circuit High Voltage
P1376 - Ignition Ground Circuit

12-06-06, 02:53 PM
I sprayed the plug wires at night and didn't get a lightshow. I replaced the plug wires anyway. It runs better but far from correct. Is there any way to test the coils?

12-06-06, 04:01 PM
Listen for arcing with a stethescope, pull then and look at the contacts for signs of arcing or what I think is the best way, swap them out one at a time with a known good one from another car.

12-06-06, 04:19 PM
Thanks, I will have a car available tomorrow.

12-07-06, 01:42 PM
P1376 - Ignition Ground Circuit

Did you re-install the ground cable that goes from the head to the coil/module bracket?

12-07-06, 03:13 PM
Yes. Asside from the engine misfiring badly the tach was randomly jumping around. I added a 12 ga. wire from the ignition module to the strut tower and the erratic tach completely went away. I can't get the engine to body ground wire off to clean it. The stud is too rusted. I'm soaking it for a while rather than risk breaking it. The clattering sound I refered to in the earlier post was the PCV valve. Just replaced it and the split rubber boot connected to it. I can here noise in the coil area. When the engine is cold or running at highway speed the engine is almost smooth, under load there isn't much power. I just ordered a complete used ignition module with coils. It is supposed to be off a wrecked 95 car. For 50 bucks its worth a shot.

12-11-06, 03:47 PM
Installed the ignition module and the engine miss is gone. The coils that came of the car don't appear to be OEM.

12-11-06, 04:26 PM
Glad you got it fixed.

12-11-06, 08:21 PM
:yeah: Congrats.

01-10-11, 06:54 PM
Another trick that I think it was Ranger taught me, is to just trade your existing coil packs around and check for spark loss and it will tell you what coil pack is bad. The one that is bad will be the one that has no spark no mattter where you install it. Another thing, you can see if the contact area is dry of grease between the mounting plates.

01-31-11, 07:15 PM
informative. thread bookmarked.

01-31-11, 07:38 PM
People are paying $50 for used ICM's and coil packs? Wow I'll have to sell my collection soon :D

01-31-11, 08:05 PM
Hey jake, on my car are the front and back coils interchangeable.. the only difference i see is the color..

01-31-11, 08:31 PM
The front and rear cassettes are identical except for color. The ICM's (in each cassette L leg) are also identical.

Ever been in there ??? here's what you're looking at.........

01-31-11, 09:19 PM
You know these things looked identical to me.. I was just asking because they are different part #'s and one is priced about $40 more than the other.. Its one of those Gm mysteries...lol

01-31-11, 10:12 PM
I guess black paint was a lot cheaper? LOL Charlie they are the same as Jim states. Buy the cheap one and paint it if you need to- but see my post; I think you may have an injector issue. Not for sure but I am just throwing my $0.02 ($0.0199701 in Canadian Dollars) your way :)