Only running on 3 cylinders Help!!

[SquashMan2009]

Ok so i did a motor swap, and i have a 4.0L in a 88 ranger. I swapped the entire fuel system and wiring harness over. Now i can get the motor to run, but only the passenger side is firing. I pulled the plugs on the other side and they are dry, i checked voltage (red wire) at the injectors and it is 12volts. All my sensors are hooked up as i can see, and all my grounds are grounded (i think). This motor was running fine before it came out. I have also changed the distrib, FPR, and PCM (i have 2 of each). The motor is from a 95 explorer. I dont know what else to think of but i cant quite get it running. The tranny is a tk4 and i just jumped the clutch wire for now. I can hear my fuel pump running and i checked pressure a while ago it was 40psi, and 30 at idle, but that was a few months ago. It also starts really rough but it will start and idle if i stay on the throttle. Any help or thoughts is appreciated please im really stuck, i can provide more info or email me if you can help as well darrellcole@hotmail.com. Thanks

 

[martin]

Sounds like the injectors are not working on the d/s, check the wire between them and the computer.

 

[Twizzler09]

That would be my first thought too.

Check your connections between the injectors and the harness, and double check each of the connectors, clean them up too if they look cruddy.

 

[AllanD]

the 1995 engine is by definition a SEFI engine so while all six injectors are supposed to have 12v positive connected to them whenever the key is on (EEC switches the ground side)

Behaving like you desctribe sounds like you have the engine connected to a batch fire (1993 or earlier) computer

Frankly I'd go looking for a ground wire... (but that's my "default" when I'm at a loss)

AD

 

[SquashMan2009]

Ok i pulled the whole intake off and checked connections, all were 12 volts like i said but now i put it back together and its behaving different, im not sure if all cylinders are firing now but both sides are going (i just knew before because one side was cold), so it will run rough with my foot on the gas, when it dies its puffying white smoke (not crazy but there is a little left over in the system), i cant tell if its unburnt fuel or lean condition. Im wondering if i should change my fuel lines the main line is 3/8 steel and the return i just used the one from the old motor. I have two computers both are the same and both are from 95's i tried them both and same thing. I will go hunting for grounds but more ideas is appreciated. Im gonna check fuel pressure again tomorrow so i will post what i get thanks guys keep it coming.

 

[SquashMan2009]

Allan you got me thinking with your post, im kind of confused what you mean switchs the ground side, do you mean when its running the opposite side will have power now? I was somewhat confused when i saw it because i couldnt find where it would ground but now that would make sense to me

 

[Nhaz]

When you think of a electric circuit and switches most people think that a on off switch is on the input side of the circuit so to speak. But you can put a switch After the device as well and it does the same job.

This is what Allan is talking about. so instead of

Pos-->--(switch)->--(injector)->---- Neg.

its

Pos-->--(injector)-->--(switch)-->--Neg.

In effect the Ground side of the injector is switched Not the positive side. and its all run through the computers box for the switches.

I would be going over all the grounds carefully. If that fails I would be looking as a possible failure on the computers part.

 

[bronco_lou]

Does the engine block have a ground wire connected to it?

 

[Big Jim M]

Yep!

Does the engine block have a ground wire connected to it?

Yes it does have the ground wire attached to it... But there is no specefic ground wire for either of the above examples...if that was your question!
Big Jim

 

[bronco_lou]

So now both sides are firing? will it run? if so while running pull a plug wire one at a time from the coilpack to see which cyl(s) is not running.
I just put in a 4.0 that was pulled 1 yr ago, it was only running on 4 cyl, after running it a few times it was hitting on all 6, I figured something was clogged on 2 injectors and cleared itself out.

Louis

 

[SquashMan2009]

Ok update, i checked all the grounds and basically grounded everything and it wouldnt even run it would kick and rev up but die. Then i decided to pull the MAF sensor off and what do you know, its running like a champ. Well i wouldnt say champ but it idles and is behaving like it should, dont know if it has power never tried to drive anywhere as i pressed the clutch in to notice there is no clutch... Im gonna look at it somemore tomorrow and i have another MAF for it so hopefully i can get it running nice.