Razberry

I’ve got a 95 4x4 m/t with a 2.7 3rz fe. I JDM swapped it earlier this year after my dad blew up the original engine. I know JDMs are questionable, but the one I put in it is great. It has been running perfect since I swapped it in late April. Anyway…

After around 5k miles, I rotated the tires and changed oil filter a few days ago. I went to start it up, and it cranked but wouldn’t fire. We pinpointed the EFI relay and replaced it, and it started right up and drove fine.

Well since then it has taken more cranks to fire up, but it always fires and runs perfectly smooth. I am getting a p1300 code. I have cleared it and it came right back.

The p1300 should shut down the fuel because the ECU isn’t getting the right signal from the ICM and it thinks the engine is not running, correct?

This doesn’t make sense because it runs fine.

I’ve read it could be bad wiring/ground. So I removed the ICM and the ground mounts were pretty rusted-see photo. I also ordered a new ICM just in case.

The connectors and wires seem to look good from the ICM, what else should I check?

Could it be the coil inside the distributor? That is the original code it’s showing…No misfires or anything though…

2ToyGuy

Definitely clean up your grounds! So many people ignore them, but they are part and parcel of any circuit. Believe it or not, current flows from negative to positive. If you have a bad ground, you have no negative to supply the voltage required to operate a circuit. If you have a badly corroded ground, as shown in the picture, it's no different from having a corroded hot connector. Check the ground from the battery down to the parts involved. If the ground shown is any example, you have some problems. You may run into other problems caused by bad grounds, so check them all, especially if other troubles crop up while you're working this one.

I know, I tend to carp on grounds, but I spent my working life as a Radar Tech, and Electronics Shop Supervisor. We were able to correct SO many problems caused by corroded ground points in the site vehicles, as well as our radar equipment. They matter.

Does that help at all?
Pat☺

Razberry

Thanks Pat,

I went over all the other grounds, including the battery, and sanded them down making them all secure.

I also checked continuity between the igniter and the ecu and the distributor. From what I could find on the internet, I think they are ok.

Tomorrow I’m going to work on thoroughly cleaning up that igniter ground and see how it runs from there.

I should also note that since this issue has been happening, I’ve noticed that the fuel pump runs for a few seconds after I turn the key off. It used to always run when I put the key in the ON position, now it does not do that and instead runs after shutoff.

Razberry

Ok, so I cleaned up all the grounds today.

I started the truck and it cranked up after a second, but the fuel pump still ran after I took the key out.

So I figured, how could power be getting to the pump after the key is out. The only answer would be a stuck relay. This would also explain why it takes a second longer to start, if the relay sticks in both open and closed positions.

So I put the original relay back in, and she fired up quick and the pump did not run at all after shutting it off!!

I’m gonna order a genuine Toyota relay now, since the original probably will stick like it did at the start of all of this.

Also, the p1300 code would not appear until I started up the truck, ran it, and shut it off. Then when I would start it the next time, it would appear as I soon as it cranked up. It is gone completely now, at least I hope, I’ll drive it for a few days and see.

I can only assume that somehow, the sticking relay was making the code appear, though that still doesn’t really make sense as it is on a different circuit. But all seems to be well, so if it doesn’t come back, I won’t worry about it.