Misfires, retarded ignition timing...

[Highbeamz]

So my car decided to have a fit on the highway (of all places)...when I was going to pass someone the engine missed and the rpms dropped. Now it started doing this only when the engine would hit boost, it would bog and the engine would try to stall. Now as I kept driving (trying to remain outside of boost) it gradually got worse, and started missing almost constantly. I used my scangauge and found that cylinders 2,4 and 5 were missing a lot, I think 5 was the worst one (but I forgot). Now the weird part is it just suddenly stopped. The car drove perfectly fine all of a sudden, everything worked normal. Now I checked everything with my gauge, no codes thrown, no more misfires...BUT I noticed once the car was running good again, the ignition advance was STUCK at 10.0. I've never seen my car go that low except for when I was running open cone filter and the engine bay was TOO hot. Now I remembered when I was running through parameters on the gauge as it was missing, when it would miss, the ignition timing would go REALLY low, like 2.8, 5.2...etc.

So I want to find the culprit in this. The car now runs fine, but the ignition timing is still at 10.0. Could this have been caused by a bad tank of gas, I did just recently fill up before I took that trip, like right before I got on the highway...I also have thoughts it could be the fuel pump? But would that cause the ignition timing to retard like that?

To help, I've done new plugs (NGK Iridium), wires (Delco), fuel filter, PCV this last year (within 6 months of now).

Thanks for the help in advance

[BNaylor]

How many degrees of knock retard (KR), if any? Poor gas could cause higher KR which will retard the ignition timing. It was premium gas? It is not unusual to get contaminated gasoline during the winter months so that could be a valid assumption. Water or excessive moisture is common. Try running some Heet additive through the tank. 12 oz per 10 gallons.

[Highbeamz]

Originally Posted by BNaylor

How many degrees of knock retard (KR), if any? Poor gas could cause higher KR which will retard the ignition timing. It was premium gas? It is not unusual to get contaminated gasoline during the winter months so that could be a valid assumption. Water or excessive moisture is common. Try running some Heet additive through the tank. 12 oz per 10 gallons.

I didn't check the KR unfortunately...

I can only assume a few things, either the ignition system was randomly acting up (or could be a problem for the future), or I got bad gas, or there was a water issue, I forgot to add that I'm running a cold air box even in the winter, which was designed to be fairly safe, but I was driving behind vehicles which were kicking up a LOT of snow and some slush...i could have been sucking up water too.

I restarted the car when I got home, the ignition timing is back to normal, and the car seems to be acting normal again...

[BNaylor]

Originally Posted by Highbeamz

I forgot to add that I'm running a cold air box even in the winter, which was designed to be fairly safe, but I was driving behind vehicles which were kicking up a LOT of snow and some slush...i could have been sucking up water too.

What brand CAI or is this a fenderwell CAI?

Just cross your fingers and hopefully the issue won't return.

[Highbeamz]

It's not a brand name intake, it's custom. An insulated box that takes air from the fenderwell, with the filter inside the box. There is nothing to stop water from entering the box other than the tube's location...it's fairly high up and quite short...

It seems there could be many variables to the misfire...if I had an A/F ratio gauge I could have watched for lean/rich conditions...but I guess I'll just see how it goes I guess, everything seems to be in order, for now.

[Highbeamz]

It's not a brand name intake, it's custom. An insulated box that takes air from the fenderwell, with the filter inside the box. There is nothing to stop water from entering the box other than the tube's location...it's fairly high up and quite short...

For all I know it could have been a fault with the ignition system, somewhere. It could have been the snow getting into something that's not what it should be...a contact to the PCM, cracked spark plug, coil pack, etc.

It seems there could be many variables to the misfire...if I had an A/F ratio gauge I could have watched for lean/rich conditions...but I guess I'll just see how it goes I guess, everything seems to be in order, for now.

[ballard2327]

I beleive it probably was your gas.The same thing happened to my 04 GP.I used the water remover in my tank and the problem was gone.I hope this helps.