i recently did a 3.4 swap in a 93 pickup eng starts ok but seems to be running rough like a missfire, havent hooked up the o2 yet, would this possibly causing my issue? ive changed wires,plugs,coils,and injectors still no change, i then found my ECU had rust internal as if it was left in the rain, re pinned a 96 4runner ECU and still no change.. any help would be appreciated

 

wire up the obd2 port and throw a scanner on it. Get the codes, watch the live data.

Not having the o2 hooked up could cause driveablity issues, but you need to get a scanner hooked up so you can read any fault codes.

 

i got my o2 hooked up and got a scanner on it i got random misfire, #3,#4,#5 misfire, already changed plugs,wires, and coils, looks like im looking at faulty injectors or base engine, gonna check compression tomorrow, anyone got any suggestions??

 

got my compression checked 0psi #3 looks i got a crap motor

 

i got everything straightened up and running ended up overhauling top half of engine, now im noticing a longer crank at times before it starts, what fuel pump is everyone using in these swaps?

 

Stock fuel pumps. Did you wire like a 3.0 COR or 3.4 COR? I had long crank times before I gave 12v to my ECU at the PWR position. Something to check...

 

checked fuel pressure all good now, still got a long crank though, not getting spark, checked my entire circuit from battery to ignitor to ecu and all looks good, re sanded the body were ignitor bolts to, no change, anyone got any ideas on any other circuits to check that could cause my no start?bad ignitor possibly?

 

what year was the 3.4 came out of? The earlier version of ECU expects to see 3 wires from Throttle body while the later years have 4 wires.
I think one of them goes to the igniter...I'm not sure. It's been a while....

 

3.4 came out of a 02 tacoma, the thing is only noticed the long crank after headgaskets was replaced, started up fine before headgaskets was done. geting pretty frustrated with this issue. any help would be greatly appreciated

 

Does it show any code?

 

no codes, but when it starts it runs fine no hesitation nothing

 

Sounds like something didn't get put back correctly after the HG.....maybe a vacuum line or crank sensor?...

 

Thanks for the response, wouldn't a vacuum line make it run rough also, crank sensor is a possibility ill check that when i get home

 

checked my crank sensor all seems ok, checked B+ at ignitor 12V key on, i also got 12V at each coil, checked ground at ignitor and case of ignitor ok, checked signal from ECU to ignitor when cranking i have signal, load tested integrity of B+ and ground wires ok, looks like i got a faulty ignitor, anyone got any input or other suggestions that would help better isolate my fault?

 

If you dont' want to spend money buying unnecessary parts, try swapping the ignitor with a buddy with the same engine.