1991 4Runner No Spark

I purchased a 1991 Toyota 4Runner V6 Manual on the cheap. The owner had a 1992 Truck engine swapped in. He said a dealer put everything in. Everything mechanical is complete. All electrical is complete. I have got fuel to the rail. I have power going to the computer and the computer has a good ground. I opened the ECU up and don't see any issues, nothing fried. I have done the tap test on the igniter like some other forums suggest and it seems to be working. I have researched everything I know and now turn to some other advice. Anyone else have this issue before?

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I'd say ignitor or coil.

Is the coil body grounded good?

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TBItoy said:

I'd say ignitor or coil.

Is the coil body grounded good?

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Internet badass Toyota guy right here.

I believe I read where it grounds by the mounting bracket. I will check ground on it tomorrow. I will try another igniter if I can find one at the local pull a part. I had some trouble with the ignition. The key would not turn. It was locked by the safety pin. I read that I could remove that pin. Once removed it rotates and everything else seems to work. I say seems because I was also wondering if there is something else the ignition might not be doing. I do get the Open Relay, EFI Relay, ETC. Just an added part I did not want to leave out. I don't get my Check Engine Light when the ignition is turned on. I read that the ECU grounds it when the ignition is turned on. So I pulled the plug from the ECU with the purple wire that goes to the Check Engine Light and grounded it. By doing that the light comes on. So it tells me my ECU is not working or not being given the signal to work.

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So it sounds like you found the root cause (ecu)....?

They do go bad, especially if the truck has ever been in water above the rockers. Toyota mounted them in a stupid location.

I don't suspect what you did to the ignition switch had anything to do with it, I've busted and pulled the lock cylinder on a bunch of junk Toyotas to get them cranked. Even drove my 4runner with no lock cylinder for a while

This is my only issue with the ECU being bad. I still have the 4Runner ECU and I have plugged it in thinking it would at least run shitty. It does the exact same thing. No check engine light. I did read that the Mass Airflow Sensor can keep it from firing also. I do hear the flap moving inside the instake box where the MAFS is located. I need to check it again and make sure it's sending a signal back to the computer. Thanks for the help and will get these checks done and see where I'm at.

Pretty sure the maf only keeps the injectors from firing, not the ignition.

I'd focus on the ignition switch since it worked before. Whatever you removed might have actuated something, or a connector pin may have got pushed back into a plug somewhere

Okay I guess that left some confusion the way I explained it. When I purchased the vehicle the key was in the ACC position not the lock. So I wanted to see if the key fit the doors and turned the key to the left and removed. After that the key would not work. The only thing I touched on the ignition was a 2 wire electrical lock. its held on by 2 small phillip screws and I did not unplug it. But what tells the lock to open? I was wondering if maybe the ignition is bad and the lock was not being told to open with the key inside. Not sure the pin out on the ignition but now it's got me thinking. I will do some research on it. Just wanted to clear that up so we don't get off track.

I have spark. I haven't got it fired up. It was already dark outside and I feel like it's probably going to need some starting fluid to get it to run at first. But out of all the troubleshooting and searching it was right under my nose. I had even done test on the Mass Air Flow Sensor and it checked good. Guess the checks was just a crap shoot. I ran across this post and went out to mine, pealed back the cover and low and behold there it is. I still don't have a check engine light. But I do have a spark. It sounded like it wanted to fire up a couple times but I'm sure it's because it's been sitting. I will have more time tomorrow and hope to get this old jewel up and running.

https://www.yotatech.com/forums/f116/3vze-not-sparking-check-engine-light-wont-come-190314/index2.html

Mo came through for me and let me borrow a couple MAF Sensors to try and the bad news it did not fix my issue. I do have spark since I fixed my MAF. But now I am back to square one. No check engine light and now that I have spark I don't have Injector Signal. I have power on the positive side. The negative side is grounded by the computer. Which is also my issue with my CEL. I checked continuity from the negative side of injector to the ECU and it's good. I'm leaning very heavy still that the ECU is toasted. I have good E1 ground. Battery negative terminal off, check E1 ground on ECU to the chassis near ECU mounting and on front fender and it checks good. So now I need to find an ECU from a local pull a part hopefully.