At witts end

WilliamSpitzer

New Member
Jan 17, 2013
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Fulks Run, VA
I've got an 86.5 N/A Supra, head gasket has been done, car just rolled over 90k miles, and I'm at witts end trying to figure out why it wont run, first

Parts replaced searching for the problem:

Fuel pump
Fuel filter
ECM

Symptoms:

I went to the car wash a couple weeks ago when it was nice, so there was a line. Pulled in, shut my car off. When a bay opened up i went to start my car, and it was idleing between around 800 and 1500 rpm's, bouncing setadily and quickly between the 2. I pulled it in anyway, washed it, when I went to start it, nothing. turned over, but wouldnt sputter or even attempt to start. I pushed it out, didn't see anything obviously wrong. sat for 10-20 minutes, and it started right up, purred like a kitten. Jumped in, rushed home while I had it started. Got home, parked, shut it off, started it up, ran like crap, barely idleing over around 600 rpm. Then the above 3 symptoms happened again, in the same order before it wouldn't start at all. Put fuel pump/filter in, finished, put in gas, started it up, ran great. Shut it off, put all my tools away, tried again, nothing, wouldnt start. Hauled it to the shop, he tested the relays, fuses, checked wiring. Put in ECM, didnt fix it. there is no power to the diagnistic port, and the fuel pump isn't turning on when you crank. The check engine light isn't on when the switch is in the run position (so you can't check codes) the fuel pump can be supplied with 12v dirrectly and the car will start, but runs very rich. I'm out of ideas, I feel like the diagnistic port not getting power is where i need to start, but I'm stumped, unless the switch is bad, causing the port to not get power? Any sugestions/things to check would be greatly appreciated.
 

WilliamSpitzer

New Member
Jan 17, 2013
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Fulks Run, VA
jetjock;1911466 said:
Ho can you be stumped when the TEWD shows how everything is wired? Worse, what kind of shop works like that? You actually paid them?

not really a shop per say, just 2 guys that do some repair work on the side of thier actual jobs. Its not costing me anything because he owes me a couple favors for some parts vehicles I gave him in the past couple years. I put the fuel pump and ECM in, just can't think of what else coukd be causing intermitency.
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
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You have to fix your diagnostic system before anything else. Otherwise you're just wasting time. It's very possible that whatever fix that system needs may also be stopping the car from running correctly.

Dont run around guessing. Fix the diagnostics system.
 

jetjock

creepy-ass cracka
Jul 11, 2005
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Redacted per Title 18 USC Section 798
Can't have diag with an unpowered ECU. No +B = no diag. A simple fix or at least simple to find out where the problem is. Not that diag will help because once there's +B the problem will likely be gone. But no, better to just throw parts at the car. I don't get it.
 

WilliamSpitzer

New Member
Jan 17, 2013
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Fulks Run, VA
suprarx7nut;1911677 said:
You have to fix your diagnostic system before anything else. Otherwise you're just wasting time. It's very possible that whatever fix that system needs may also be stopping the car from running correctly.

Dont run around guessing. Fix the diagnostics system.

well the switch has to be "on" for the diagnostic port to get power i assume, so thats why I was thinking it may be a bad switch.
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
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WilliamSpitzer;1911800 said:
well the switch has to be "on" for the diagnostic port to get power i assume, so thats why I was thinking it may be a bad switch.

Uh... I don't follow. If you don't get a cel at any point, that's a problem. B+ should be 12v. Always. Its connected to the battery, or at least supposed to be.

Sent from my Galaxy Nexus using Tapatalk 2
 

Nick M

Black Rifles Matter
Sep 9, 2005
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jetjock;1911466 said:
what kind of shop works like that? You actually paid them?

I am guessing no. Or they are "low bid".

WilliamSpitzer;1911623 said:
not really a shop per say, just 2 guys that do some repair work on the side of thier actual jobs. Its not costing me anything because he owes me a couple favors for some parts vehicles I gave him in the past couple years.

Anyway, have you figured it out yet?
 

WilliamSpitzer

New Member
Jan 17, 2013
4
0
0
Fulks Run, VA
Nick M;1913221 said:
I am guessing no. Or they are "low bid".



Anyway, have you figured it out yet?



Not yet, I downloaded a pdf of the Toyota book with the wiring diagrams, just gotta print out the parts I need and start tracing some wires, ive just been too busy with work and school. I can get the car to start by feeding the fuel pump 12volts at the sending unit under the carpet, it idles really crappy and runs rich, but that means its not a fire issue either. I'm gonna try to convince myself to work on it a little bit tonight when I get home from work.