Hi Everybody!

So Ive been a long time lurker of Yota Tech. Well I've read about 12 different peoples 3.4l swap descriptions to the point of feeling like I could do it with my eyes closed. Then I went and read several threads on problems people have had just to make sure I was prepared if I had the same problems. I went and got schematics from toyota and mitchell on demand from my old 93 4runner and the 97 4runner donor engine then traced all the circuits out on paper before ever wiring anything. With all of the research I did, I felt like this would be an easy and fun learning experience. NO!

After simply wiring the few pins of the computer that needed to go into the truck body harness I went to fire it up and 'sputter, crank, curplunk, boom, 700rpm, sputter, die'. Long story short I found out the original computer had a faulty ground in the fuel injector circuit and they werent firing. I ran alcohol down the throttle body and it ran great. No problem, Ill just get a new computer.

New computer had different plugs, though everything else was the same, so I had to wire the computer pins to match the harness. Easy enough since the schematics are so easy to read. Now its all wired in and it cranks, but no fire. I am not getting spark or fuel. I went back and traced the circuits to verify I have everything in place, and yes its all in the right place. I tested the circuit voltages and everything is good up till the computer. The computer is not supplying ground to anything. This leads me to think I am missing a signal somewhere and am probably overlooking something oh too obvious.

I really hope someone can help me figure this out because I feel pretty bummed that I was an ASE certified master tech for several years and I am having the hardest time getting this truck to run.

thanks for your time and any help you can offer.

Mathew

 

I just realized I posted this in other engines and not in 3.4l engine swaps. I don't know how to move this or delete it so I can repost it in 3.4l.

 

for the most part wiring up the harness to the computer should be enough. the body harness doesn't really do much but help you with the gauges etc... the biggest thing is the COR. if you are getting power to the ecu, then the efi relay should be starting. I would double check the wiring. is the computer for the same year as the motor, engine harness?

 

what year ecu are you trying to run with the 97 harness? auto or manual? Give us some more info on both the rigs.

 

The rig being swapped into is a 93 4runner with the 3.0l and a manual transmission. Sr5 package, otherwise a very skin and bones setup.

The 3.4 I bought came from a 97 4runner with a manual transmission, I don't know much else because it was already pulled and the truck long since crushed by the time I got to it.

The new computer came from a 97 with a manual transmission as well. I don't have many details because I bought it on ebay.

Perhaps there is something wrong with my wiring to and from the EFI relay. Its dark out now so I cant go look and be too effective, however tomorrow if I don't collapse after I get done working I will definitely go and check it over again.

Like I said though, Im sure its something silly and right in front of me. I just need another mind or two to help guide me.

 

You don't say that you're getting power to the ingiter. Check to see if it's well-grounded.

And Merry Christmas.

 

This for sure. I took a small wire wheel on a drill and cleaned the mount of the ignitor and the metal it would mount to really well.

Also, the fact that the plugs were different for two manual 97 ECMs would be a flag to me, but i could be wrong. They should be the same. What are the part numbers on the ECMs that you had (assuming that this the ECM the motor came with) and the "new" one?

 

OK, So I have power to the igniter (black red wire), I have power to the coils which then comes into the igniter (IGC 1,2,& 3), so there is power up to there. The actual igniter ground is good. However there is nothing coming from the three signal wires to the computer (IGT 1,2, & 3), though this should be pulse generation only, and with a no start condition there is no reason to have pulse generation.

I popped up a red flag on the computer plugs as well, I chatted with some Toyota parts guys and techs for a bit, and sure enough both computers have been used for manual transmission. Seemed odd to me, but then again Toyota does like to use things as universally as possible.

Here a pic of the plug setup I currently have hooked up. The pic is of an Auto Trans computer, Mine is listed as a Manual trans. This is the part number on mine (89661-04410) I do not have a part number on the old one, the sticker was faded and torn.



Goodness this is a pain in the butt.

 

I really think that you have a 98 ECM there instead of a 97. Check out Jeff's (Mosk) stickie thread in this forum and see if what he has there under 98 matched what you have. I have a 97 Runner ECM, 3.4, 4x4 and that is not the same part number although there are a few different number for the same year, model ECM.

Take a pic and post the ACTUAL ECM that you are using as well please.

 

I will definitely take a pic as soon as I get home and the sun is out. Thank you for your advise thus far.

 

89661-04410 is a 98, all 98 manual ecm's use the larger plugs like the auto ecm's.

 

Ya, so a pain in the ass but not a disaster. You are just going to have to repin everything for a 98. I believe everything else should be the same as far as the sensors on the motor go so you shouldnt have any issues there but hopefully someone else will confirm or dispel.

Use Mosk's pinout sticky thread and the EWD for a 98 to help you repin everything.

I did the same thing and I tried to document the process in my thread. It wont be the same but similar and should give you an idea on the process.

Jason

 

AWESOME!

I found his thread, and though its for Tacoma trucks it will be of great help. Thank you soo much for the help on that one. I will keep you posted on my progress as I re-pin the computer.

 

I think that you are much MUCH better off buying a 97RUNNER ECM and then selling or forgetting that one. Sucks up front but I think that the amount of hair you save from not pulling it out will be worth it. If you end up having an issue or two you will not have to wonder if its the compatibility or does this work with that, etc.

Check car-part.com for ECMs. The are listed under computer box.

I bought mine for $40 which was a great deal but they usually are about $75ish. i just searched over there and there are at least 20 of them for $100 or less.

Also, if you go to a 97 ECM, I can send you all the diagrams as well.

 

Dtnsdad,

I looked too, there are several that are like $75-$80. I think that might just work out best, especially if you already have diagrams setup for a 97 4Runner engine swap. I looked over your whole swap and I like the attention to detail you gave. I also noticed that your body harness plugs are identical to mine which makes things super easy.

I looked over the pinout chart that most made and there are only a few differences between what I have wired right now and what the 98 computer requires, though I am unsure about the cross over between a 4Runner and a Tacoma.

 

Just for the record, I dont have a "conversion chart" for the ECM I used to a pickup or whatever. I wasnt that smart to do that. I wish that I had. What I can give you is all the EWD's that I have, and any advise that would be useful as you go along.

Jason

 

Hey Jason,

Thats fine with me, I think instead of going at it all alone and accepting the experience and help of others who have actually done it would have helped me avoid this mess to begin with. Maybe not the original computer being bad, that was kinda a fluke. Anyhoots, any help I can get or experience of what not to do is greatly appreciated. At the moment I might not be doing any work on the truck because after almost two months of no snow it finally happened and though Im happy to have the snow, working outside on frozen wires is no fun.

 

did you get it working? i'm doing a 3.4 swap now with a 97 auto harness and 1998 5speed ecu...and am pulling my hair out as DNTSDAD said.....