toyota corolla 2003

nickb2

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Hi guys, long time no speak, need help with an electrical issue. Alt fuse 5amp in engine comp blows. No fuel, crank fine, 4th cyl at 60, all others at 210. Anybody know if this is a ECM issue or I got to rip the wiring
If billr is out there hi, and jim f also, :thx
 

billr

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Well, it's nice to hear from you again, but I gotta ask... what is going to happen with that cylinder with only 60 psi?
 

Jim Fairbanks

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Hey Nick...glad to see you back......have you tried to disconnect the plug on the alternator and see if the fuse still blows?.....it may be a short in the alternator causing it to blow....has the alternator been replaced lately?....Jim
 

nickb2

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no, alt is still original, problem is the car is in gravel, and at least 100ft from any electrical outlet. I do not want to throw parts at this. This personal for me cuz this a good freind of mine. My two laptops have low bat, need replacing, can't keep them alive long enough to pin test. Don't know the neigbors and my buddy doesn't live close to there. My gut feeling is maybe a ecm issue but cannot trust what my buddy is telling me. He has had other freinds to look at it, not a trained mecanic like me. So the funny thing is, he goes and buys a fuel pump on ebay, and give it to me and this the problem. I go see the car, the rear seat is ripped out. I check it, connector to pump is still loose from othe guys checking. Seat the fuel p conector and proceed with basic tests. Compression great on 1 2 3, 4 is only 60 while other give 210. This car has major issues and just don't want to throw parts at it like i said. a 2003, ok. just go buy another one, might be cheaper. Cheers jim, thx for the reply, and if you got a wiring I can download cuz my allld is rippied, much apreciated, just used to working in better circumstances. Cheers guy

Will be back here soon and giving out more advice. I just hate working in crappy gravel pits.
 

nickb2

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Bill, threw some oil in cyl 4, no hike in compression, so geussing a burnt valve. This is why I am thinking a ecm issue. Bad transistor driver issue throwing to much fuel. Exhast valve. But the alt 5amp fuse is throwing me off. So like I said to jim, car has some major issues and just don't think it is worth it. Plus the environment is not kosher and it is still cold up here. My knuckles will hurt. Now I am sounding like the other Nick. Is he still alive :ROFL He always had $.02 worth. :ROFL Hope that guy is doing well. best to all.
 

billr

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Yep, NickD is still here. Is that alt controlled by the ECM, or does it have a conventional voltage regulator?
 

nickb2

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Still guessing, but these old nippon denso in my opinion were still integral to the alt. Evrery short from a alt that I have seen always blows the main fuse. Godd question, will ponder this. Thx bill. Internal volt reg is probbly related to ecm for excitation only, and that would explaind the 5amp fuse. A nice electrical delima, A SWEET defi as we say in french!
 

billr

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I looked in rockauto, they show a voltage regulator, and it sure looks like the type that would mount in the alt; no field control from the PCM. That VR may still be powered by the PCM, though.
 

nickb2

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ok, finally got wiring, wht wire to alt. 5amp. Will go see the car n question again, far from me, north of st hyacinthe. will check resistance, and see visually if all wiring is sound with my trusty old xacto, will also sand down all grounds that I can see. But my gut feeling still tells me ecm but schematic tells another story. Buddy said it stoped on a dime while turning a corner. He checked it out again with his freind last night and now he says comp is at 170 on cyl 4. I think the oil i put yesterday settled in and set the rings. good news. he left his key to me, so i won't feel like a monkey that u throw peanuts at. this is not a simple fix. thx all for help. will post a fixed one on this when i am sure, this thread may help someone at one point. Beating cars is fun, but hell on the one who fixes em
 

nickb2

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thx jim, just confirmed what you said wht wire, will isolate, fuse cant blow, will still have crank no start but it narrows it down. Damn I miss u guys. Experince is a teacher, and even if you have the nicest toolbox, it never came with a garantee that you have a crystal ball in your pocket :idea:
 

nickb2

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Ok, really pissed offed now, ecm under center console, isolated all grounds and power distribution. Buddy said put the fp. I said no, I will just bypass it, guess what, it works. Duh. Gravel in my butt, and am certain this is ecu related. Last I was so lost on a electrical issue like this was a nissan maxima MT this car would crank and give me cam and sensor good data. I was so lost called nissan help line. They told me to buff the cochon (bell housing) and try again, damn, it worked, every tech in the shop was flabergasted. Bad ground due to corrosion, bad signal to crank sensor, engine and pcm thinks it is running, flooding engine large. Anyways i might just give up on this one, not worth my effort. :thx
 

billr

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So, it is running now, but pretty much on just 3 cylinders, or did he just have a bad reading that first time?

Edit: Did that buffing for a good ground take care of the fuse blowing as well? Was there a typo there, or did you really call Nissan for help with this Toyota??? I wouldn't put that past you, you are known to be quite assiduous in your trouble-shooting!
 
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