Cylinders 2 and 4 not firing. HELP

[justgio928]

So I just got finished dropping in a 22re into my 87 SR5. The previous 22re had a heavy knock and was on its way out of this world. The old engine also would not fire on cylinders 2 and 4. There is a spark when I pull the plug but the idle of the engine does not change when I pull it while running.
Now that I dropped the new motor in, the same issue is occurring. My only thought is that it could be from one of the components that carried over to the new motor. I moved the fuel rail (with refurbished/matched flow fuel injectors as of a month ago), intake manifold, and vacuum lines. The coil is the same as the old motor and I haven't replaced the wires, distributor cap/rotor, or plugs that came with the new motor.

Any suggestions or thoughts? Would a bad coil cause just cylinders 2 and 4 to consistently misfire since the firing order is 1,3,4,2?

Thanks!

 

[SV_Dude]

It could be a number of things. I doubt it's the coil because the coil sends power to the distributor, if half of the cylinders are firing then the coil is doing its job. I would replace the cap and rotor, plugs, and wires first. Those are cheap and if you have a new motor it wouldn't hurt anyways.

 

[justgio928]

It could be a number of things. I doubt it's the coil because the coil sends power to the distributor, if half of the cylinders are firing then the coil is doing its job. I would replace the cap and rotor, plugs, and wires first. Those are cheap and if you have a new motor it wouldn't hurt anyways.

Alright I replaced the cap, rotor, plugs, and wires. I swapped the coil from my other 4runner and the distributor itself and that made no difference either. What else could it be? Could it have anything to do with specific sensors or the intake manifold? Evap canister? Etc? This is super frustrating.

 

[SV_Dude]

How do you know that they aren't firing? What are you doing that leads you to believe that they are not firing?

Also, if you have a good cap, rotor, plugs, coil, ect... I would check to make sure that they are in fact getting fuel. You already said that they are getting spark. Make sure that your injectors are firing and the cylinders are getting fuel. Also, check the lower intake plenum and make sure that there aren't any obstructions in the plenum leading to the 2 and 4 cylinder.

 

[the_dingman]

Cyl 2 and 4's fuel injectors share a line to the ECU. Could be a short to ground, or a bad ECU. I'd take the plennum off (it sucks, I know... Label ALL your hoses), and check continuity between the two, and then the connections at the ECU.

 

[SV_Dude]

Cyl 2 and 4's fuel injectors share a line to the ECU. Could be a short to ground, or a bad ECU. I'd take the plennum off (it sucks, I know... Label ALL your hoses), and check continuity between the two, and then the connections at the ECU.

Their signal wires are all bridged, the grounds are separate though. That doesn't mean the wires inside of the harness near the injectors aren't bad though.

 

[justgio928]

How do you know that they aren't firing? What are you doing that leads you to believe that they are not firing?

Also, if you have a good cap, rotor, plugs, coil, ect... I would check to make sure that they are in fact getting fuel. You already said that they are getting spark. Make sure that your injectors are firing and the cylinders are getting fuel. Also, check the lower intake plenum and make sure that there aren't any obstructions in the plenum leading to the 2 and 4 cylinder.

When I've tried pulling the spark plug boots to 2 and 4 while it is running, there is no change in the engine but it instantly kills when I pull 1 or 3. I put a screwdriver to the injectors and listened and I know at least number 2 was buzzing. I just had all the injectors serviced by cruzinperformance so I'm pretty positive they are functioning. I'll have to check the obstructions when I get back to Utah.

 

[justgio928]

Cyl 2 and 4's fuel injectors share a line to the ECU. Could be a short to ground, or a bad ECU. I'd take the plennum off (it sucks, I know... Label ALL your hoses), and check continuity between the two, and then the connections at the ECU.

I have a spare harness that came with the engine but I just kept everything connected on the ecu side when I pulled out the old motor. Would swapping in that harness help with that? I also am going to get the ecu (for an 87) from the guy I bought the motor from and try swapping that in as well. Should I do both at the same time or would it be better to do one or the other?

 

[SV_Dude]

If you get them for free then you can do both, but when finding a problem it's best to just do one thing at a time so you can find out what is causing it.

 

[justgio928]

If you get them for free then you can do both, but when finding a problem it's best to just do one thing at a time so you can find out what is causing it.

I'll probably just switch out the ecu first then since I can just pull it from the passenger's side. Which would be more likely to be the issue in this case and where it has carried over from one engine to the other? With the old engine, when I first bought it, the power to 2 and 4 was intermittent and at high rpm's it would sometimes get power for a few seconds.

 

[justgio928]

Cyl 2 and 4's fuel injectors share a line to the ECU. Could be a short to ground, or a bad ECU. I'd take the plennum off (it sucks, I know... Label ALL your hoses), and check continuity between the two, and then the connections at the ECU.

How should I go about checking the continuity between the two? Could you explain that or point me to a thread that discusses it?

I replaced the ecu with another and the same issue is persisting so I'm guessing its the wiring. The wire harness I got from the guy is for an automatic trans and has some different wires then what is already on mine.