The Dreaded Misfire Saga Continues

[etc]

Yeah, I know it's of no help to you.

It's something in the ignition system I would think?

[lostinthe202]

So if all the objects that could cause this code have been replaced (which it sounds as if they have) then that leaves only the wires running to these right? Too bad you can't swap harnesses easily!

 

I'm sure you did this, but in case you didn't, when you were changing the different sensors, ecu, etc. did you inspect each plug to make sure each connector was firmly seated?

 

That's too bad this hasn't gotten resolved with extraordinary amount of work that you have put into finding the problem. I guess it's a good thing you don't live in an area that requires no CEL to pass inspection!

 

Good Luck!

 

Will-

[davebugs]

I'm imagening that swapping the intake swapped most of the wiring and connectors that you speak of. If the sensors were already swapped guesses are getting scarce.

 

I had a car just like this so I'm looking forward to a conclusion. Not as much as the OP - but still anxious to see it resolved.

 

Dave

[lostinthe202]

I'm imagening that swapping the intake swapped most of the wiring and connectors that you speak of.

 

I meant the harness portion that would goes through the firewall. I can't imagine trying to inspect all of those aside from maybe the points where they go through sheet metal like maybe a grommet ripped or something.

 

yikes!

[subsince77]

The little black plastic mounting bracket for my radio antenna is cracked a little - could it be leaking a small amount of electrical pulse that is traveling into the car and tricking the ECU into thinking it is hearing a misfire?

 

Hey, seriously, this is sad, but I know I have read that there were some ECUs in this vintage that had problems. Yes, I did already replace the ECU with another used one, would there be any point in throwing another one at it? Probably not.

 

I was thinking about the rest of the wiring that runs through the firewall too. I have no motivation to even think about attacking that now. The car runs SO WELL! We drove about 60 miles today doing some X/C skiing. It purrs like a kitten. Actually, for some reason, with the new intake it even idles smoother - my wife even noticed it. Ya just have to ignore the light.

 

Thanks for the interest everybody.

[etc]

Plugs and wires? Maybe I should try that:grin: Sorry, glad that fixed your problem. I've done plugs and wires multiple times over the several years I've been chasing this problem.

 

Yeah, it fixed it for one day. I am aware from the old posts that you tried already. I've done since then -

 

Plugs & Wires

Fuel filter

Coolant Temp. Sensor

O2 sensor

 

My next stop is just swapping the coil and the Fuel pressure regulator, whether they need it or not, I am that aggravated. Total loss of power and not moving when cold.

[89Ru]

I'm having misfires with my '97 OBW, same symptoms (blinking CEL while letting off gas down hills, in high vacuum conditions). Misfires occur more often on long drives than short hops. I have all the codes showing P0301,P0302,P0303,P0304 or sometimes pairs.

 

This summer I hosed out the engine compartment crannies where leaf litter tends to collect, mostly around the perimeter. The next day I drove 500 miles through PA hills and the misfires which had previously been sporadic (sometimes not for hundreds of miles) suddenly became frequent and not just on hills, say 10-15 misfires on that long trip. After the overspray dried up, so did the frequent misfires. Maybe wiring got wet, who knows. Car still ran fine wet or dry same as always.

 

Two months ago cam timing was corrected (lower right side) by one tooth. At the time I thought that the cam jumped a tooth earlier that day, it had fresh misfire codes and was running bad (hard starting, stalling, etc.)

 

Its only been two months but it hasn't misfired since then, granted this isn't conclusive given the low frequency of the problem...and what's to conclude? Accidental harness wash or cam fix? Since your misfires have crossed engine swaps I don't know how this helps...just my two cents.

 

edit: forgot to mention the coilpack had a bad connection that was mated properly during the cam timing fix. The plug wire was barely making contact with the coilpack, probably for months, since the repeated flashover had almost totally eaten away the housing around the coilpack contact. None of this blind mate stuff, need to pull back the boot, visually mate the wire, and then push the boot over the connection. Most folks know this already, seems like I'm still learning the basics.

Edited November 1, 2009 by 89Ru
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