vtec9

Hello,

MY2000 AP1

I got a sudden flashing CEL this morning and parked the car after about 50 feet (first safe place). Felt like severe constant misfiring (like I was trying to go from a stop in 5th gear, engine hesitating, bucking, loss of power, etc.. was certainly not a one shot misfire).

Car was towed to dealer, and was diagnosed with misfiring in two cylinders due to bad ignition coils. I do not have the specific codes, as I only spoke to them briefly over the phone, but I will certainly get the specifics when I pick the car up. I will be towing it car back home tomorrow to do all work.

plan of attack:
replace 4 coils
replace 4 spark plugs

Now, if the coils are the real culprit (I'm assuming the diagnosis was correct at this point), what else should I do just to be safe?

Oil change to remove unused gasoline?
Valve adjustment/valve inspection?
Compression check?
Map sensor cleaning?

Should do all of these regardless? I'd hate to replace the coils/plugs and fire her up only to cause damage due to a bent valve or something.

Thanks

vtec9

Thanks for the feedback. I just picked up a compression tester and obd2 reader today!

New plan

pull the codes to confirm
compression test
replace 4 plugs
replace 4 coils
If compression test looked ok, clear codes and give her a rip.

vtec9

Codes were for misfire in cylinder 1 and 3, diagnosis both coils bad (dealer emphasized that the tech said bad coils for sure)

COLD Compression results:

1: 253, 220, 220, 260, 255
2: 232, 234, didn't bother again
3: 228, 241, 243
4: 233, 242, didn't bother again

Higher readings on #1 were with 10+ second crank, all the other readings were in the 7-9 second range. I was happy with the results.

Replaced all 4 plugs (oem)
Replaced all 4 coils (new brand new, two used low mileage, although they looked more beat up then those I removed with 200k)

Let her rip. Solid CEL. Idled normally. Drove about 20 feet forward then back into the garage, and it seemed fine.

Waiting for OBD2 reader to come in tomorrow so I can check codes again, clear, and make sure it doesn't return.


#1 plug definitely had gas on it, so it was clearly misfiring. #3 didn't look like it has much if any gas on it. #3 and 4 were noticeably darker than #1 and #2.

The tips look fine but the washer/threads are gunky, so I think my plug tube seals are leaking. When I peeked down inside, they looked dirty. I ran dual krank vents for over 100k, and now that they're removed, I burn a decent amount of oil.. 1qt every 2k. I'm semi-concerned with #4 but the pics definitely make it look worse. There was no wet oil near the tip. Valve cover is getting total gasket replacement this spring when I re-paint it.

plug pics. how do they look? They've been in about 90k. Was difficult to get good lighting at 6:15 pm