2G 2G No injector pulse, no spark.

[TupperWare]

I got a 98 Eagle Talon TSi non running. I've done a bunch of wire tracing to find out that the ECU wasn't powering on and for some reason not triggering the MPI relay. Someone has messed with this wiring harness so I didn't feel bad putting the relay on a switch. Got ECU to power on, fuel pump turns on with cranking engine I know the fuel pump relies on the cam sensor I checked and it was okay. I have power to literally everything. I get no pulse at injectors and no spark. When I tested the crank sensor is was questionable so replacing that will probably be my next go. I've been looking and can't find a definitive answer if the crank sensor is what triggers the fuel injectors and spark. Does anyone know that it is what controls it. Also what are other things I can look into?

 

[luv2rallye]

Need CAS for injectors and FP. Need both CAS and CPS for ignition (CPS says when, CAS says which spark plug pair).

 

[steve]

I'd start by figuring out why the ECU wasn't powering up by itself. Depending on what you did with the switch you may not be powering everything that would be normally.

 

[TupperWare]

Then I'll get a hold of some noid lights to test the injector pig tails and test the CPS again.

And I was going through a post you made a while ago, Steve. About what's needed to power the ecu. I went through and I had everything that was needed to trigger the MPI relay to give power to the ECU. But when the ECU saw ignition at pin 82, it didn't trigger the relay. This made me think it's the ECU, the car came with 2 ECUs for some reason. One is the normal blackbox, and the one that was plugged in was a 95 EPROM turbo ecu. I tried both ECUs and did the same thing. I put a switch on the relay and tested all the sensors that get power from the relay and they all get power. One thing I forgot to mention was that the ECU was powering up fine if I recall. Then I played around with the MPI relays to test them then when I put them back I had no power. The relays tested fine.

 

[TupperWare]

Think I've narrowed it to a bad crank sensor. When I measure the voltage signal out it's at v5.05 but when crank it doesn't move at all.

 

[motomattx]

Think I've narrowed it to a bad crank sensor. When I measure the voltage signal out it's at v5.05 but when crank it doesn't move at all.

You cant really test the output when cranking with a meter very well, the voltage changes to rapidly.

 

[luv2rallye]

DC voltmeters read average when measuring pulse trains. The average CPS voltage I've measured while cranking was around 2.4V (and 2.0V while idling). When not turning and key on, it's pulled high to 5V.

 

[TupperWare]

Yes I know I tried looking for an analog meter but couldn't find one. I was able to test the cam sensor with success and saw rapid change in voltage. I can only assume that it's the same for the CPS, and I'm concerned that it doesn't do anything and stays at the 5.05 the entire time. Wouldn't the car still start without a CPS just run very poorly? Or is the CPS relied on to run at all?

 

[luv2rallye]

Digital voltmeters also read average DC voltage of pulse trains so you can use it (CPS should read around 2.4V average while cranking). You need CPS to run at all since it tells spark plugs when to fire. CPS should not stay at 5V while cranking/running. Where are you measuring? Some possibilities: A broken wire on the CPS, bad CPS, crank walk which pushed the sensing blade into the CPS and destroyed it, broken B-belt which bent the sensing blade which then destroyed the CPS.

 

[TupperWare]

That last part is what I'm scared of . I'm probing the blue wire with white stripe on the CPS plug harness side with it plugged into the CPS.