ecu question

[black_red_rs-t]

i just bought a 91 eclipse gs turbo and it doesn't start. I know the fuel pump doesnt turn on so its either bad or its just getting power. (no fuel comes from the fuel line feeding the fuel rail when i disconnected it and turned the car over) now the reason i'm asking if it sounds like the ecu is that I cant get spark and I've replaced my cam sensor, power transistor, and coil with known working ones from a friend's 93 NT but I still cannot get any spark. I pulled the ecu yesterday, there wasnt a noticeable smell when i opened it. I didnt get all into it and take a big whiff or anything but from what I've heard the smell should be pretty obvious. any help would be appreciated. let me know if theres anymore info i can give to help solve my problem.

 

[silver bullit]

http://www.vfaq.com/index-main.html

 

[toybreaker]

When you turn the key to the run positition, the ecu should power up.

This will illuminate the check engine lite for ~ 5 seconds, (and then it will go out.)

The boost gauge in the dash should read ~"0".

If neither of those things happens check fuses/power supply for the ecu.

The caps are a problem in these cars, and can kill an ecu. A visual inspection as per the tmo site will find many problems.

http://www.tmo.com/howto/ecu1g/caps.html

Good luck, and keep us posted as to what you find.

 

[Shaggy_357]

On a side note, I know it sounds rather redneck-ish, but a nice solid whack on the fuel pump should liven it up. Both of my DSMs sat for a while and I had to rap on them both to get them to wake back up.

On the ECU, the smell SHOULD be obvious, but not always. When I bought my AWD, it had a blown comp, and it didn't smell until I took the thing apart.


Eric

Edit: Has anyone checked the fuel filter? Are you getting fuel to it at least?

 

[cbassgsx]

mpi fuse controls spark and fuel

 

[black_red_rs-t]

I did look at the board and it looked like one of the caps might have leaked but its kinda hard for me to tell. I checked the fuses on the battery first. Those all appear to be good. I was thinking about getting some replacement caps and taking it to the computer store down the street and have them change those for me. At least until I get another ecu since I cant think of any other reason why I can't get spark/ fuel I have a brand new fuel pump just in case that is bad though.

 

[bling5tatus]

mpi RELAY controls spark and fuel

Fixed

 

[steve]

On a 1G the fuel pump will try to run when the starter is cranking. The pump runs from the same ignition fuse on the battery terminal that powers the solenoid to the starter. So it the starter is cranking the fule pump side of the MPI relay should be activating and switching the battery to the pump. Measure the voltage at the fuel pump check connector during cranking to see if your getting battery voltage.

The ECU gets it's power from the MPI fuse on the battery terminal and when you turn the ignition switch to RUN the CEL should turn on for 5 seconds then turn off. On turbo cars the boost gauge should move to the 0 and start there until you start cranking the engine.

If these don't happen of the CEL turns on and doesn't turn off then ECU isn't running and nothing interesting is going to happen with the engine. The ECU must work for the engine to run.

So the MPI fuse does indirectly control spark and fuel, since the ECU drives the coils and injectors, but the power for the fuel pump and for the coils comes from the ignition fuse not the MPI fuse.

 

[black_red_rs-t]

it did turn out to be the ecu. i put in the ecu from my 90 turbo laser just to see if it made a difference and it did. i have spark now. everything is working as it should for the most part now. so i'm probably gonna get my eclipse ecu fixed or just buy a new one. thanks for all the info and advice.