At witts end

[WilliamSpitzer]

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.

 

[MightyAl]

Sounds like ignition relay to me. That kind of inconsistency in starting but the idle issues don't match.

 

[jetjock]

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?

 

[WilliamSpitzer]

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]

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]

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]

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]

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

 

[jetjock]

+B is the Main Relay controlled feed. BATT is the Keep Alive.

 

[suprarx7nut]

+B is the Main Relay controlled feed. BATT is the Keep Alive.

Argh, durr. :dunce: I got batt/+b and +b/acc all jumbled up.

Thanks for the correction, JJ.

Sent from my Galaxy Nexus using Tapatalk 2

 

[MINA]

Did you check the fuse under the hood for the ecu
Also check cap and rotor and wires

 

[jetjock]

...Thanks for the correction, JJ...

Done only because you're one of the very few who rarely needs it. Make sense?

 

[suprarx7nut]

Done only because you're one of the very few who rarely needs it. Make sense?

Only because I pay attention to the right people around here...

Sent from my Galaxy Nexus using Tapatalk 2

 

[Nick M]

Fuel pump
Fuel filter
ECM

Those are some expensive guesses without testing. You put a fuel pump in because of a rolling idle?

there is no power to the diagnistic port

 

[Nick M]

what kind of shop works like that? You actually paid them?

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

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]

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.