2006 4.0 misfires

[mijbr90190]

Hey guys, last week the truck started acting up a little. Would get choppy around 20-25mph if I gave it gas. Got a cyl 1 misfire code. Swapped coils packs on those cylinders and cleaned the maf. Spark plugs were new with head gasket repair in August. Yesterday it started acting up and I had to pull it over. It would barely move. Pulled the codes and the codes were related to each cylinder misfiring and the CEL was flashing. I restarted it and it cleared right up. Took it all apart at home and check the connections. Everything looked good. Pulled the negative terminal and let it sit for an hour. Fired right up and didnt miss a beat. Drove it to work today and no issues. It seems like after it runs for a while or I drive it somewhat spirited, the miss occurs. When it first started acting up, I had just filled the tank. Could this be bad gas?

 

[djpope09]

Hey guys, last week the truck started acting up a little. Would get choppy around 20-25mph if I gave it gas. Got a cyl 1 misfire code. Swapped coils packs on those cylinders and cleaned the maf. Spark plugs were new with head gasket repair in August. Yesterday it started acting up and I had to pull it over. It would barely move. Pulled the codes and the codes were related to each cylinder misfiring and the CEL was flashing. I restarted it and it cleared right up. Took it all apart at home and check the connections. Everything looked good. Pulled the negative terminal and let it sit for an hour. Fired right up and didnt miss a beat. Drove it to work today and no issues. It seems like after it runs for a while or I drive it somewhat spirited, the miss occurs. When it first started acting up, I had just filled the tank. Could this be bad gas?

I think it's bad gas. I had a similar issue last October. The truck had been sitting for a while waiting for some repairs. Once it was fixed it ran great. Driving it home from work the next day it started to misfire about 15-20 minutes into the drive. Cylinder 1 misfire.

I swapped coils, plugs, A/F sensors with no change. I swapped injectors from cylinders 1 and 3 (with new o-rings) and it didn't seem to fix it either. It would always misfire as soon as everything was warm. The fuel economy/range gauge would show decreasing MPGs while it was misfiring to the point where it would read E00 as the MPG.

I put some new gas in it and the problem hasn't come back since. I would start there before you start spending lots of money on parts.

 

[mijbr90190]

I think it's bad gas. I had a similar issue last October. The truck had been sitting for a while waiting for some repairs. Once it was fixed it ran great. Driving it home from work the next day it started to misfire about 15-20 minutes into the drive. Cylinder 1 misfire.

I swapped coils, plugs, A/F sensors with no change. I swapped injectors from cylinders 1 and 3 (with new o-rings) and it didn't seem to fix it either. It would always misfire as soon as everything was warm. The fuel economy/range gauge would show decreasing MPGs while it was misfiring to the point where it would read E00 as the MPG.

I put some new gas in it and the problem hasn't come back since. I would start there before you start spending lots of money on parts.

Thanks for the quick reply. I'm hoping that fixes the issue. Gonna grab some higher octane fuel at lunch today and a bottle of techron. Dont want to start throwing money at it (this thing has been a money pit for me due to PO lack of care) Yesterday when all cylinders started misfiring had me really worried.

 

[mijbr90190]

Just got home and gave it a spirited drive around the block. After flooring it a couple times the p0303 code popped up now. So from p0301 to p0301-p0306 to p0303. Turn the truck off and back then its fine. Any ideas before I starting throwing money at it?

Edit: I think I answered my own question, lol. I swapped the coil packs on 1 and 3, and the misfire went from 1-3. Lol. I'll update the thread.

 

[waypoint]

Stick with Toyota or Denso replacement ignition coils.

 

[mijbr90190]

Stick with Toyota or Denso replacement ignition coils.

Just picked up a denso one. Funnily enough the one that was bad said "4/18" in marker and had no brand. Made it a year.

Replaced it earlier tonight and drove the piss out of it. Couldn't get it to show the same signs as before. Hopefully this fixes it.