Cranks but won't fire

[604CruisinCroat]

All day i've tried to get her to start. She cranks but won't fire.

I'm getting fuel but no spark so I changed the spark plugs, CAS, coil pack, mpi fuse etc etc. Timing belt and compression are good.

I'm leaning towards the ECU and transistor now.

Any thoughts?

 

[bluegs03]

There is an easy way to check the ECU, turn the key to the on position and see if the turbo gauge goes to 0 also see if the check engine light disappears after 3 seconds.

 

[EagleTalon1993]

Something I would also suggest is to check the power transistor for the coil if it's bad no spark at all. Unfortunately most places cannot test it.

I would first check and see if the coil is getting 5v on the harness side when the ignition key is in the on position, Also your CAS should be getting 5v on two of the leads going to the CAS if your not may be bad ECU.

Hope this is helpful

 

[604CruisinCroat]

Well I changed the power transistor and again it wont fire.

I checked the CAS voltage when key was on the "on" position and it read 3v.

It's not the CAS because I swapped it with a working one and it still didn't start.

The things I have changed so far are:

CAS
Coil pack
Power transistor
Fuses

The next step I guess would be ECU....or even coolant temp sensor?

 

[604CruisinCroat]

Should I try swapping the MPI relay?

I'm so stumped.

 

[604CruisinCroat]

Oh and I wanted to add that my boost gauge does not move AT ALL, even when cranking.

 

[juanpac0]

Oh and I wanted to add that my boost gauge does not move AT ALL, even when cranking.

Sounds like an ECU issue to me.

 

[604CruisinCroat]

Should I try changing the mpi relay first?

 

[604CruisinCroat]

My check engine light does NOT come on AT ALL, as well.

 

[steve]

Sounds like you have identified one of the reasons it won't start, the ECU isn't running.
That could be because the ECU is bad or because it's not getting power.

Get out the voltmeter and start diagnosing the issue. Pulling out the ECU and checking it for leakage is also a good idea at this point. Until you get the ECU powering up nothing else is going to have much impact.

I've posted what goes on and provided links to the factory manuals.
Here's a few links:
http://www.dsmtuners.com/forums/problem-diagnosis/239406-no-power-ecu.html
http://www.dsmtuners.com/forums/newbie-forum/321572-i-need-help-no-spark.html
http://www.dsmtuners.com/forums/problem-diagnosis/167545-how-tell-if-ecu-bad.html
http://www.dsmtuners.com/forums/newbie-forum/293581-why-my-mpi-relay-not-working-right.html
http://www.dsmtuners.com/forums/pro...-dead-ecu-no-check-engine-light-when-key.html

1G DSM Technical manual dtm
1G Engine/Chassis/Body 90-91ecb
1G Electrical 90-91el

 

[604CruisinCroat]

Sounds like you have identified one of the reasons it won't start, the ECU isn't running.
That could be because the ECU is bad or because it's not getting power.

Get out the voltmeter and start diagnosing the issue. Pulling out the ECU and checking it for leakage is also a good idea at this point. Until you get the ECU powering up nothing else is going to have much impact.

I've posted what goes on and provided links to the factory manuals.
Here's a few links:
http://www.dsmtuners.com/forums/problem-diagnosis/239406-no-power-ecu.html
http://www.dsmtuners.com/forums/newbie-forum/321572-i-need-help-no-spark.html
http://www.dsmtuners.com/forums/problem-diagnosis/167545-how-tell-if-ecu-bad.html
http://www.dsmtuners.com/forums/newbie-forum/293581-why-my-mpi-relay-not-working-right.html
http://www.dsmtuners.com/forums/pro...-dead-ecu-no-check-engine-light-when-key.html

1G DSM Technical manual dtm
1G Engine/Chassis/Body 90-91ecb
1G Electrical 90-91el

Thanks Steve.

I pulled the ECU and there are some black marks around the caps.

 

[604CruisinCroat]

All I want to know now is could it be my MPI relay even though I am getting fuel but no spark?

 

[juanpac0]

All I want to know now is could it be my MPI relay even though I am getting fuel but no spark?

I believe the MPI controls fuel as well, so no.

 

[kstoopsdsm]

I am having the same problems on my 420a. Shut her off for the night, and the next morning nothing. She cranks but wont start. I have replace fuel pump swapped relays with another 420a, along with ignition coil and wires, and even the CAS. Ive looked at the ecu but i dont see any leaking caps or such. But I also have no check engine light when key is in on position.