Hello i have a 1990 3.4 swapped 5spd 4x4 pick up and the motor, harness, and ecu are out of a 1996 m/t tacoma. i bought the harness from toyonly swaps. I have been having issues with it running lean once it gets up to temp. it runs but not great until it gets to temp then it has no power. Ive been searching different forums for similar issues but none have solved the problem. Ive checked the timing, check the compression, crank position senor, replaced the temp sensor at the front of the engine, and the O2 sensors. I was wondering if anyone has any other ideas. or if maybe some of the pins for the harness are switched around

 

Just what if any codes are you getting ??

Some of these Swaps can be quite interesting till all the bugs are worked out.

Then just what do you mean by No Power ??

Is it lacking for fuel ?? Fuel line kinked when changing things around

I am guessing the Fuel Filter was replaced maybe the fuel pump ??

 

Maybe your clutch is worn out.... Does it run good before it warms up? if yes, then that's not it....

 

thank you for your replies. Its not the clutch, I checked it before i put the new motor in. When i say it has no power i mean it feels like it wont go over 1800 rpms once it is warm but it almost seems likes it mis-firing . When i first start it up it runs alright but not perfect. i replaced the fuel filter and checked all the lines. i know the fuel pump is working, but is there a possibility it wouldnt pump as much fuel once it is up to temp? It isnt throwing any codes. but a weird thing is it wont even read/connect when plugged into a OB2, I bought another ECU thinking that may have been a problem, but its doing the same thing with both ECUs

 

I didnt mention. it only starts running like crap when i shut the truck off after getting it up to temp and start it back up. if i dont shut it off it will run well enough, but like i said not as well as it should

 

Does your Mil come on when the ignition switch is on?? Lets start here!!

Not being able to connect to the OBII might mean some wiring problems or corroded connection maybe bent pins

The wiring done by Toy Only Does it come with Prints showing just what was done People can and do make mistakes .

I can`t recall is it them that have poor after the sale customer service

Changing parts without knowing they are bad can make things even worse by compounding the problem adding more unknowns into the mix

 

I'm sorry im not sure what Mil stands for. But it didn't come with the schematic for the new harness

 

Mil- (Malfunction Indicator Light) or also known as Check Engine Light.

 

could be faulty O2 sensors. sending bad info to the ECU. when the engine is cold it runs on a different MAP, once it warms up the O2 feedback kicks in.

 

You need to hook up a scanner that can read live data at the OBD diagnostic port. The computer could have Pending codes on it, or its receiving bad data from a sensor and is trying to run off that data. Looking at the live data will tell you if its running lean or rich, Engine coolant temp, O2 readings, etc.

 

Sounds like it is off. Where your cams lined up? Is your bottom crank pulley tight? I seen a dude with a 3.4 on Youtube with a finger loose pulley on bottom of Timing belt. Bad cam sensor? Crank sensor? Sounds like one of those issues to me