Needing help with drivability issue

[JAMIEPACURN]

Just a few days ago my car seems to accelerate ok but occasionally will hesitate making the check engine light flash then quickly goes away. When going down the highway at 70mph with cruise control on the car severely hesitates with the check engine light quickly flashing then goes away. The driveability at this speed is just terrible! I checked all my scan master readings and everything is fine. (No malfunction codes at all). I checked the "orange" ECM wire to the battery and do not see any troubling wiring. All connections to the battery are tight and solid. I then pulled my MSD ignition plug wires and made sure they were all snug at the coil and spark plugs. (No issue seen) I pulled the spark plugs from cylinder one, cylinder two and spark plugs look nice and tan. I did notice that I can wiggle the coil pack back and forth slightly even though the bracket underneath the coil pack is tight. The car seems to idle okay its just acts up when in gear. Any thoughts on this issue?????

[Keller]

Grounding issue perhaps? Or maybe the ECM is damaged.

Try reseating the chip and the CALPAK chip in the ECM, as well as the connectors and see if that helps.

[JAMIEPACURN]

I will take a look at the chip and see what is even in there. Perhaps I need to upgrade to a new chip like Turbo Tweek. I know prior to my car started to act up my radio doesn't work now........does not even power up. Don't know if there is a possibility that these issues could be related or an isolated coincidence??????

[kenmosher]

I'd look really carefully at the fuse box and see if any fuses are blown. Also, check the harness where it goes into the top of the ECM and see if there is chafing, corrosion from moisture, etc.

[JAMIEPACURN]

Thanks Ken I will inspect all my fuses and check the ECM connection. I will update this in a few days when I have more time to inspect this problem further.


Jamie

[PaCemkr86]

Any updates on this? Does the car have any aftermarket stuff? Volt booster, Maf Etc ?

[cadillac]

I would remove the bracket and coil/module assembly.
The use a little dielectric grease between the module and bracket where
it touches on the raised portion. Then tighten the 3 nuts securely.
IF the module does not have a very secure ground to the bracket/motor
it can short or just not work. The coil/module should NOT move around on the bracket. It you see evidence of corrosion between the module and the bracket, it may be too late. A coil may be shorted. Many times if a coil shorts the module becomes damaged so replace both if needed. Highway Stars.com recommended as I got 2 new ones in a row from the local parts store that were defective.

[JAMIEPACURN]

Well thanks everyone for the information. Hopefully, I can tighten up that coil pack so it will be more secure and possibly being the only issue. Will work on the car Monday night and see what the issue is.

[JAMIEPACURN]

Update: Took apart the coil and inspected the wiring. Everything appears okay. Checked the wiring harness that plugs into the ignition module and that appeared fine. I did however replaced the worn out electrical tape and replaced with new. The ignition module is loose and discovered the whole thing is being held down by one nut underneath the bracket. The other two nuts were completely missing. So that was why I was having play in the ignition module. However, still could possibly be bad ignition module and coil.

Orange wire inspected: Do not see any bad connection, cuts in the wire, and connection to battery solid.

Starter wiring has not been inspected yet.

[Keller]

Was the bracket held to the angled bracket (made from round stock) by a bolt and to the intake with two nuts? My bolt in the rear has never fit well, and I'm sure others have found theirs missing if prior owners have not put it back securely.