So ive got the 3.4 in and all hooked up but cant get it to fire. Ive looked at my wiring and all the colours are different from what ive been searching. After searching i found that the possible issue be either efi woring or ign 1 wire but i swear i cant find the white with light blue wire as stated in the Ewd for the 97. Anybody have a better idea on my problem or maybe what colour wire i need to look at?

 

Did you download the wiring diagrams for both vehicles and draw out a diagram of how to wire things up? If not, start there. Otherwise you are chasing a needle in a haystack.

:wabbit2:

 

I did download them and have traced out the wires and id say 99% chance they are hooked up properly. So it could be any number of problems? Any idea where to start?

 

Double and triple check wiring.
Grounds. Missing one it won't do squat.
Check your wiring again

:wabbit2:

 

So by not having the OBDII wiring, this would be no good? As it seems the new gnd comes from that wiring. I was rushed out of the shop and wasnt aware fully that i needed to have it to run.

 

You shouldn't need to have your OBD-II hooked up (at least lots of guys on here have gotten their swap running without it), but I would recommend that you splice ALL your grounds in your swap harness together then run a wire with a ring terminal on it and bolt it to a clean metal surface in the kick panel to definitively provide a ground (rather than assuming that there is a true ground somewhere in the harness).

Something that hung me up for a while was ECU pin numbering. I spec out a fair amount out wiring connections for work and the numbering scheme we use is 100% backwards from the one that Toyota uses. On my swap I had 2 of the 4 ECU connectors backwards, rewired them and the truck started first time. I think its the 3.4 Swap 101 thread that explains the proper pin numbering scheme. (As it turns out, I now have 2 fully functional ECUs because the pin numbers were backwards).

If that still doesn't do it, wiggle/push-in the wires on the MAF and igniter and those same wires on the ECU connectors; if they're not fully connected the ECU will not allow the engine to start.

If you're still at a loss, look at the repair manual, there's a section under .../Engine/Diagnostics/Engine_5VZ-FE that gives trouble shooting tips and what to check for each of the various scenarios.

Make sure you have continuity everywhere you should and verify that all the sensors are operating correctly.

I hate to say it, but now is the "fun" part chasing down all those little issues. Good luck and I hope its something simple.

 

I had the same problem where my motor wont fire. It cranked fine but wouldn't start. Hooked up a ODBII scanner and scanner won't read the ecu. ECU would get very hot to the touch. Turns out that the evap sensor was either a) damaged or b) wired wrong. So it might have been shorting out the ECU. I unplugged it and it ran first try. Here is a list of things that you can try to unplug to find the culprit. Best thing for you to do first IMO is to wire up the ODBII, get a scanner and work from there. If the scanner is reading the ecu then this method may not work for you...

Here is a list that you can try to unplug. Good luck!!


-the MAF
-Igniter
-ignition coils
-TPS
-O2 sensors
-IAC (idle valve under throttle body)
-vsv's
-cam/crank sensors
-injectors
-coolant sensor
-knock sensors

 

I dont have evap hooked up at this time as i want to get it running first since im using my old 3.0 can. Do i need to plug those in to get it to run then?
Cause my motor does crank beautifully but wont fire.

 

I'd almost put money on your COR relay wiring. The rest of it is pretty straight forward. You don't need evap or obdII hooked up for it to run. You might just have to take a break from it, and come back to it in a few days. I had to do that several times.

 

Thats my plan now, take some time off, and when i go back at it i am going to really dive into the details.

 

What vehicle is this going into and what motor year are you working with.

For the ones that I have done, the W-L (white/blue) wire is the most prevelant wire in the whole harness as it powers almost all the sensors on the motor. Weird that you cannot find it on the 3.4 harness. The feed from the EFI fuse for both of my swaps was a W/R wire coming from the under the hood fuse panel. It was right there in the kick panel feeding the old 3.0 ECM.

 

do you have all the connectors? the 2 body plugs from the 3.4 and the extra plug that goes into the ecu from the 3.4 dash harness. I just finished another 3.4 harness last night *97runner>91truck* Does it run if you spray some starting fluid in there?

 

yup i have all the connectors from the 3.4. and i have not tried the starting fluid, would it not require a spark though?

 

If it fires on starting spray you can assume you probably have a fuel problem. If it does not, start looking into electrical.

 

Start with the basics- backprobe (check without unplugging) for power at an injector with the key on, and power at the ignitor... you need to see what & where you aren't getting enabled.

 

Well im so close to getting this truck going but ive come to one of two problems. When i was moving the trucks around on the property to get them in the garage the battery was no good from the 3.4. So we did something bad not thinking. We started it with a good battery then took it off and let the truck run for at least 30 min with no battery. So now i think i could have fried my electrical, mainly my ecu. How can i test my ecu to check if its still good or dead.

 

Uh, put a battery in it and see if it runs?

 

No no, this was before the swap.

 

If your car runs and no CELs...you should be fine.

 

lol, okay let me explain further, BEFORE the swap was started, i had to move both vehicles into the shop, the 3.4 battery was no good, so hooked up a good one and then pulled it, the vehicle then sat for 30+ min running with NO battery. NOW i have the 3.4 in my truck, new battery, wiring all good and ready to go, its turning over beautifully but it just will NOT fire!!!! Have i done something when i ran it without a battery before the swap? i have not started the motor in weeks, since november.