car shut off while driving. fuel pump relay? ecu? help!!

[Junkyardspecial]

Just as stated. Car shut off while driving. Won't pop start. It cranks all day and I can hear a fuel pump whine. The fuel pump relay was clicking badly when it died but now clicks on and off normally.

I just checked the ecu and all capacitors are clean and good.

 

[TWOpointFORliter]

Do you have spark and fuel? You say you can hear the fuel pump but are the injectors firing? It would be impossible to guess one of the many things that cause a no start without more info.

Start by reading this http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

 

[Junkyardspecial]

No spark now. Ecu looked great but I'm ot getting the cel to come on. I have no spark. I'm going to get a new cas and will try that.

Edit. Tried new ecu new cas new coil new transistor. Still nothing. Even with new ecu I still don't get the typical cel coming on.

So I went back today. I have a wire shorting the mpi fuse. Looks like this won't be easy.

 

[steve]

Finding shorts can be quite difficult. You don't to blow a ton of fuses to do so.
First thing you need is the FSM or a copy of the factory MPI wiring diagram like http://www.dsmlink.com/images/forums/1GECUMFI.pdf

Pull the fuse at the battery just to be sure.

There are two main legs, from the fuse holder on the battery to the input of the MPI relay and from the output of the MPI relay to the engine bay for the ECU, sensors, and solenoids.

Switch to resistance and connect your probes between the wiring side of the fuse holder and ground at the fuse holder. it should be an open, infinite resistance between the two since the only thing on that side of the circuit is the input of the MPI relay and it's open contacts.

Go to the MPI relay and connect your probes between the output side of the MPI relay and ground.
Expect some resistance between them since everything is connected normally. In your case blowing fuses that resistance is going to be 0 or low ohms. Start disconnecting the various thing taking power from the circuit and see if any of them are shorted. If you sill have a short after disconnecting all of them you know it's in the wiring and the problem just got more difficult.
Start disconnecting

 

[Junkyardspecial]

Finding shorts can be quite difficult. You don't to blow a ton of fuses to do so.
First thing you need is the FSM or a copy of the factory MPI wiring diagram like http://www.dsmlink.com/images/forums/1GECUMFI.pdf

Pull the fuse at the battery just to be sure.

There are two main legs, from the fuse holder on the battery to the input of the MPI relay and from the output of the MPI relay to the engine bay for the ECU, sensors, and solenoids.

Switch to resistance and connect your probes between the wiring side of the fuse holder and ground at the fuse holder. it should be an open, infinite resistance between the two since the only thing on that side of the circuit is the input of the MPI relay and it's open contacts.

Go to the MPI relay and connect your probes between the output side of the MPI relay and ground.
Expect some resistance between them since everything is connected normally. In your case blowing fuses that resistance is going to be 0 or low ohms. Start disconnecting the various thing taking power from the circuit and see if any of them are shorted. If you sill have a short after disconnecting all of them you know it's in the wiring and the problem just got more difficult.
Start disconnecting

This helped a lot, I found the short actually from the sparking noise but since I dont know much with wiring i used what you told me and learned quite a lot. the o2 sensor wire was stripped and laying on the transmission bell housing. I feel like an idiot for not seeing it before.

 

[steve]

Good news. Was it just the one wire that was exposed or were some of the others too?

The reason I ask is if the 12v touched the sensor ground wire also going to the O2 sensor it can blow up a circuit trace on the ECU and cause the car to run poorly.

 

[Junkyardspecial]

Good news. Was it just the one wire that was exposed or were some of the others too?

The reason I ask is if the 12v touched the sensor ground wire also going to the O2 sensor it can blow up a circuit trace on the ECU and cause the car to run poorly.

It was just the red 12v on the transmission housing. It didnt run poorly though just and on/off situation.