EFI fuse blowing...fresh rebuild PLEASE HELP!
 

I posted this in the newbie tech section but didnt get much of a response, so i guess ill give it a try here...sorry for posting twice but i really need help.

I recently bought a 1989 std cab dlx 22re 5 speed pickup.

The guy that had it before me bought it from his friend that had supposedly blown the head gasket so the guy replaced the HG and replaced the radiator, timing chain, tc cover, top end gaskets etc. He then went to start up the truck and discovered it had a HUGE knock and wouldnt stay running...so he had to sell due to family expenses etc.

So i bought the truck cause im kinda lookin for a project in the time off school etc. and LOVE TOYOTA's When i got it i pulled the engine and hymmed and hawwed about either gettin a crate engine or goin for a rebuild, as it wouldnt run and there is 217514 miles on the clock...i finally decided to go for a rebuild and came to discover that the engine had thrown a rod which bent the crankshaft...so now it currently sits with everything back together and basically new everything except manifolds...but...hook the battery up, turn the key on, the engine check light comes on for a while and then BAM! it blows the EFI fuse like a firework...i looked @ the dignostic pages (195-210) from the FSM and i get no voltage to the ECU...so i plug a good fuse into the socket while the battery is still hooked up and the ing on and the eng light comes on and same thing BAM the fuse blows....the only thing i have left to do is try another ecu...but my buddy who owns a 87 runner with another 22re is in arkansas and i gotta wait for him to get back to try that...but im not sure if there is something else i should check first...

Ive checked all the o2 sensor wiring (basically everything under the truck), injector plugs, and visually made sure there was no damage anywhere else. I dont know what to do from here. :bang:

Thanks for any help in advance ive been looking on this site for a couple of other problems i have had but this is the one that has me stumped so i must write about it.

If the EFI fuse blows, you should trace all the wires from that circuit(see wiring schematics in your manual), you can bypass a wire one at a time to single out the faulty one.

I'd also try and get ahold of an O2 harness and swap it and see if that does the trick. Just to be sure.

Go to your local junkyard and get an ECU, it shouldn't cost you much.

Not sure of anything else.

Okay so bypassing one wire at a time you mean jumping the wires from the circuit to the ecu? Or do you mean just going through each wire at a time?

Oh, and you mean by the o2 harness the plug that plugs into the sensor socket or the whole thing?

sounds like a grounded wire, chase all the wiring especially for the fuel system

Either way would probably locate your problem.

And I was suggesting the whole thing for the O2 sensor.

yep... go through all the wires in the engine bay, making sure that none of them have melted together, paying particular close attention to the ones over to the ignitor and coil and the ones that run along the engine to the injectors and sensors on the front of the manifold.
as well, make sure that all of your grounds are good- there are several around the engine bay. bad grounds can cause current to flow through the wrong circuit and blow fuses.
make sure the coil is hooked up correctly as well.

Thanks for the clarification,ill get to that asap. Oh, and if there was something wrong with the computer is there anyway it would blow another computer???

Um, as far as the grounds go as i was looking around last night and noticed there is this ground wire in the engine bay that is cut and hanging loose between the battery and the fusebox on the passenger side of the compartment...does anyone else have this wire? If so where does it go?

Also, it has a couple ground wires that are under the drivers side kick panel that are also disconnected...does anyone know where these go also? If i was to guess i would say to the fuse panel but i have no idea...just need an idea to start with.

Oh, and just a side comment, i hate it when you have to fix other peoples problems and mistakes...if your gonna do something do it right the first time!...anyone else feel this way?

http://i166.photobucket.com/albums/u...kpanelwire.jpg

The wire under the kick panel...
(Plus my smashed up thumb...stapleing insuation inside studs...not the funnest...)

http://i166.photobucket.com/albums/u...terywire-1.jpg

The wire in the engine compartment in between the battery and fuse...

Anybody? Thoughts?

I have been having the same problem, I am stumped, for me its not the coil. I checked everything. I did find that my alternator wiring harness was melted together but the wiring diagram doesnt show that any fuel injection wires go through that. And I know its not the coil cause I have spark at the plugs!! I even went as far as disconnection all the sensors and trying to start it and see if the fuse blew. And it did, the only think I didnt check was the fuel pump harness!!!


There is a short somewhere, I have been working on this for about 2 months and am stumped. Ill keep you posted on what all I find out.