Car still not starting..this is what i tryed

[Alex Bland]

Ok i have tryed some things first thing i tryed was a new battery. No help

Next, I went to junk yard and grabbed 2 Power transmitters. No help

Next i looked up how to test the CAS First off let me say its a 4 prong plug in (i was reading and people said only the 1990 came with 4 prong) and it goes black,red,black,white i got and i got continuity with the Black,red wires none with any others. Turned key on and no power to red wire or any other. Plugged it in with key on and no power to any of them. So I'm thinking that i have something wrong with the plug in part of the CAS. The IGN fuse is fine. and have continuity to the fuse.

What should i try next..no spark still.

 

[Alex Bland]

Ok tomarrow im on that thank you ill check relay first then ECU

 

[steve]

Ok CAS is not getting power. When i turn the car to "on" no CEL and car just cranks no spark. From all ## posts im thinking my MPI relay went out? How can i see or test? Where is it located? does this sound like my problem we changed the power TR nothing. and like i said no power the the CAS but i have the 4 pin setup on it and i get continuity between black/red wires only. i just let car sit for 2 days and this happend. thanks

On the middle ECU connector find pin 63 and ground it. That should turn the MPI relay on. You can do that with the connector still in the ECU. Ground pin 63 and the MPI relay should turn on, the ECU should power up, and the CEL should turn on for 5 seconds. That would tell you that the ECU is damaged.

I don't see many bad MPI relays, lots of bad ECUs and blown fuses.

 

[Alex Bland]

I dont quite understand. So i take some wire while the ECU is still plugged in ground one end and touch the other end to the #63 pin. If the relay is bad it wont move correct? and if the ECU is bad it wont turn on?

On the middle ECU connector find pin 63 and ground it. That should turn the MPI relay on. You can do that with the connector still in the ECU. Ground pin 63 and the MPI relay should turn on, the ECU should power up, and the CEL should turn on for 5 seconds. That would tell you that the ECU is damaged.

I don't see many bad MPI relays, lots of bad ECUs and blown fuses.

 

[doobycareful]

If you are gonna have your ECU out might as well change the capacitors (if you think you can handle it) this is where you can get the parts, and this is where some good info is on how to do it, remember do this all at your own risk, or take it to your local TV repair shop or so. If your ECU looks like my old one, you need a new one. Hope this info is some help for you.

 

[steve]

Put the wire into pin 63 first then ground it. If the MPI has power and works it will activate and switch the power to the output pins feeding the CAS and ECU. If the ECU isn't totally toasted it should turn on and you'll get the normal CEL power up sequence.

Normally we would check the fuses and measure for voltage at the right places before this but it's a quick test. You want to put the wire into the ECU connector first so you can make sure you put it in the right place before you ground the other end.

 

[Alex Bland]

i get what you are spitin..i think ill tell u step by step what im gunna do u tell me whats wrong
1. unplug battery
2. get to ecu
3. while the ecu is plugged in put a ground wire into #63 (after grounding it)
4. plug in battery
5.turn the key to the "on"
6. check to see if CEL flash's

only question i got is should i pull out the relay so i can see if its working correct?

 

[steve]

You'll have the console side cover(s) off so you'll hear the MPI relay. There isn't anything to see.

We are bypassing the normal use of the key here. All the ignition does is signal the ECU to activate the MPI relay and turn on. By grounding pin 63 at the ECU we are doing what the ECU would.

You can skip messing with the battery. If you F up it's not going to save you.

 

[Alex Bland]

alright so just like put the ground in the back of the femail side? if not ill just figure it out just has to stay plugged in