Hey guys, I am a long time lurker but this is my first post on here hoping to shine some light on a problem I've been having. I've recently swapped a 5.3 Vortec motor into my 2006 Tacoma. I finished the swap and drove great for about 3 months. I ended up needing to swap out the torque converter and decided to build the 4L65E I am using a little bit since I was going to drop the trans to swap out the converter. The issue began once I started it up after the transmission install. I dont think the trans install has anything to do with it but I wanted to preface the work I did before I had the issue.

The issue I am having is that the #2 cylinder and ONLY that cylinder keeps carbon fouling the plug. It will foul it out at idle and the engine will backfire at idle every once in a while at operating temp. The closer to operating temperature it gets the worse the backfires get.

I have checked for spark and its got a strong spark. Ive moved coils and plug wires around and the problem didn't move around. I moved injectors around with no luck. Compression checks out at 180psi on that specific cylinder. It ranges from 175 - 185 on all other cylinders. Checked for injector pulse using a noid light and the pulse is there, no different than any other cylinder. Went thru the harness from injector to ECU and no visible damage and continuity using a multi meter checked out. I went in and adjusted the preload on the lifters just in case. Changed the MAF. No codes to check either. I am pretty much out of ideas now.

I have had a similar issue to this before but it was on cylinder #3 and I was getting code P0200 Injector Circuit Malfunction. The drivers on the ECU ended up being bad for the #3 injector. I put this ECU to test out that #2 cylinder and the truck would not even run. I would feel comfortable changing out the ECU again if I was getting codes but I am not getting anything. I made sure my OBD2 was reading correctly by unplugging MAF and other common sensors and sure enough I got codes.

Any suggestions or input would be greatly appreciated I am really out of ideas. I can post pictures of anything if you guys need them. Thanks in advance!!

 

you have
compression
spark
fuel
but its fouling the plug....... AND backfiring?
fouling would be to much fuel, backfire would be not enough fuel or improper timing.
Since you have already swapped injectors I would swap the ECM again although I havent had any ECM issues, maybe you have a voltage or ground problem

 

Yes, that's correct. Do you think there can be two different issues?

There is definitely too much fuel on #2 cylinder since the spark plug is black. I will take pictures of it this afternoon.

I haven't messed with the timing chain at all since I got the engine. Can the crank and cam sensors cause this?

 

No that would affect all cylinders.
Strange that its not showing a missfire for number 2 though. Can you data log?

 

I had a similar problem 2 years ago. I found the injector on that cylinder was dumping to much fuel at idle so it would misfire. It was also leaking when i shut off truck. Took me awhile to figure out. Swapped injector and have been fine ever since.

 

Unfortunately I have no way to data log right now. I can view live data through my OBD2 reader though.

 

Ive swapped the injectors around in hope that this would be the issue. The problem still stays on cylinder #2.