misses, backfires and fuel injector issues

[evanesce69]

ok guys... i'm at a loss...

I just rebuilt a new motor for my 93 supercab 4x4. I's a 3.0 and 5 speed.


here's what's happening
1) #1 cylinder runs just fine, unplug the injector and there is a noticeable change in idle. Spark is there, plug looks good with signs of normal combustio

2) #2 cylinder is constantly backfiring through the exhaust. Unplug the fuel injector and the backfire goes away but idle does not change. there is spark, the plug has signs of normal combustion.

3) #3 cylinder doesn't do anything.. unplug the injector and no change to idle... still a bit of a miss. there is spark. the plug looks wet but does not smell of fuel

I ohmed all the injectors and the read 14.7-15 ohms. This is the second set of injectors that I have put in.


I cannot do the same on 4, 5 and 6 because they are located under the intake manifold.

New distributor, new wires, new plugs fresh rebuild with less than 100 miles. I experienced these symptoms before the new engine went in, but I though it was a bad cylinder.


ok, my question: has anyone has an ecu go bad so that it constantly fires one injector and completely drops another? I'm really getting cheesed here because I have put a shit ton of cash in this motor, copper headgaskets, arp studs, o ringed block, cam intake headers yadda yadda and another yadda.

I NEED HELP HERE! LOL!

 

[evanesce69]

Ok... So I have solved the problem.

The lesson learned through all this:. Always make sure your plug wires are on right!!!


Yes you read that right... A week of fighting it only to realize after checking the plug wires again that #2 and #3 were transposed at the cap.

Sooo... It's open season on the dumb blonde jokes...
Ha!

 

[adsm08]

Eh, we have all done it.

I fought one for 6 months with a backfire and slightly rough idle, check the plug wires 3 times, didn't find it until I was putting the engine in a different vehicle.

 

[cbxer55]

Speak for yourself, I've never done it. But then, when I put new custom wires in it some years ago, I numbered the wires top and bottom with those little things that clip onto the wires. Hard to mess it up with those on it. As long as you have the manual with the diagram of the coils, that is.

Anyway, 1, 2 and 3 aren't the problem. It's the driver's side that's the problem. 1,2 and 3 are consecutive. The driver's side was done by someone with dyslexia I suppose. LOL!!!

 

[evanesce69]

Yeah I have wire looms... That's why I didn't check them. Changed them out one at a time. Had no reason to suspect they were wrong...

I do trust my work but now I make no assumptions.