toyota whaos

[MrUPS]

I'm gonna try and keep it short. Wife has a 05 matrix with 44000 on it. Its been blowing the EFI fuse. I uped the amps from 15 to 20 (i know i know just hear me out) and that worked fine for a week or so. Well it quit last night and the the fuse didn't blow. Got it home checked the rest of the fuses and did a fuel pressure test. It has no pressure but I checked for power with an ohm meter at the pump and I dont think I'm getting any power. Theres 4 wires going into the sending unit and none of them get how with a key cycle. I dont know what to think. I know it has spark plugs and it runs on rice but you guys are a smart bunch. help me out here.

 

[madmatt]

You should be using a voltmeter or a test light instead of a ohm meter to check for power.

 

[MrUPS]

yeah. It was on volts. I just called it the wrong name. tried with a test light too. no go Thanks for checking though.

 

[madmatt]

ok just making sure you weren't barking up the wrong tree over a tester.

 

[JMK777]

check for a short in the fuse box. dose a 15a fuse pop instantly? check out the o2 sensor?

 

[madmatt]

do you have power too and across the fuse??

 

[MrUPS]

The wife corrected me, it was a 10amp to start with. Its a 20 now. The first time it happened we towed it to the garage and found the fuse blown, replaced it and it popped right away. We switched it to a 20 and it started, but had no power. Acted like it was starving for fuel. We let it sit for a day and started it up and it ran fine. Like nothing ever happened. No check engine light. Switched back to a 10 amp and drove it for a week until it blew again. Put in a 20 amp and it started right up and ran with the 20 amp until last night when it died without blowing the fuse. I checked for power again at the pump and its not getting anything. I looked over the wiring a bit and it looks ok but I don't have a diagram to really get after it. I'm wondering if maybe the computer need signal from the crank/ cam sensor before it will power the pump. I'm also wondering if the computer took a dump. Any help would be great. Thanks for all the thoughts so far.

 

[MrUPS]

Good thought Matt. I have 11.75 key off and 12.03 key on across the fuse.

 

[Chevy1925]

Sounds like you have a short somewhere in the system. try pullin the fuse block and look underneath it. may have a wire that has worn through the insulation as is broke/shorting to ground.

 

[496 BB]

OR adding 10 more amps caused 10 more problems. Check out here for what I mean on max load of smaller wires. http://www.powerstream.com/Wire_Size.htm

I thought Toyota is starting to say now that they think some of the ECM (or maybe it was the programming IN the ECM) were bad and that was causing some of the recent problems. I got a 97 4 Runner with no probs (except it feels like the rotors are warped like hell when I stop but they are newer)....knock on wood.

Either way if your popping a fuse you have to have a short somewhere. Sucks but ya gotta keep tracing. First off make sure on your fuse panel that it calls for a 10A and not a bigger one to begin with...like someone changed it before or something. Check around your rails and see if salt/corrosion compounded by engine compartment heat has deteriorated any wires. Hell Ive had a mouse eat a damn ignition wire going to a coil pack that I chased for months! Found it by accident when I wiggled it and it shut off.

Get some beer and have at it! :thumb:

 

[madmatt]

Remember also, once you key it up the fuel pump 12v power wire probably only goes hot for a few seconds. May want to have someone cycle the key while you're under it checking wires. It may also go hot for a few seconds when the key is shut off as well. That's just how some auto mfgs work their systems. May be different on your Toyota.

 

[05' Ditry Duramax]

Maybe the relay on the pump is going bad and causing the fuze to blow so it doesn't wipe out the relay on the pump itself?

 

[MrUPS]

Update. I said Uncle. The car is at the local toyota seller. I suppose I should just get the vaseline out now. Ill let you know what the issue is.

I did think about the pump only getting 12v for a few sec. so I was ready for that. I checked under the fuse box and under the hood and under the dash for corroded/chewed wires. Didn't see any. I wondered about the relay so I switched it with a matching relay in the fuse box. Should know more tomorrow. thank you all for the helpful ideas. I appreciate it.

 

[496 BB]

You know its gonna be something incredibly stupid and easy dont you? It never fails