Hope for some help or confirmation.

While on the track last weekend car had a brief stutter and then engine stopped running.

Once in the pits found that the radiator sprung a leak and the front of the engine was dripping wet. No water went above the throttle body and no water anywhere near the PCM. The car DID NOT over heat. I have separate Autometer water and oil temp gauges wired directly to the Autometer sending units and looked at them when the car shut down (220 & 240 respectively).

Here is where I am testingwise:

1. Fuel to rail. I used the Fuel Pump Prime pigtail near the PCM to make sure.

2. No spark at coil while cranking.

3. Opti harness (from Opti to large white connector next to valve cover) tested for continuity.

4. Tested Ignition Control Module 4 pin as follows:

A = Battery Voltage (12.4) (Consistent with Shop Manual)

B = Manual says 1vac-4vac while cranking. I tried this and got 0 on the meter when the ground lead from the meter was held on a ground.
BUT when I tapped the ground lead on the ground voltage showed up.

C = 0 ohms to ground with key OFF (Consistent with Shop Manual)

D = Battery Voltage (12.4) (Consistent with Shop Manual)


5. Tested the 4 pin from the opti with the key ON except for D as follows:

A = .25 vdc (Manual says ~5vdc)
B = .25 vdc (Manual says ~5vdc)
C = 12.4 (Consistent with Manual)
D = 0 ohms with key OFF (Consistent with Manual)

No spark at coil tells me that the ICM could be bad except I am concerned about the Pin B test result because this voltage comes from the PCM. If I am getting the correct voltage at Pin B, then PCM is working and Opti is probably the problem, if not is there a problem with the PCM?

However, I am most concerned about the Opti 4 pin test for pins A & B. The DC voltage is significantly lower than the 5vdc that should be coming from the PCM.

Any help with this would be greatly appreciated.

 

I don't have anything for ya there, except maybe a PCM if you're a 94-95 unit. I didn't even pull the car off the trailer since the last event, just snapped in a throttle cable and drove the car on old tires for Friday practice. Car was a mess! HPR does not like old tires like Pueblo. I suffered through 3 sessions with them and mounted my 3 cycle tires for Saturday morning. Also bled the brakes and swapped out rear pads for some used trailer garbage. From there I just drove the car, it was nice to have it cooperate again. Videos are in work, should have them up soon.

 

OK . . . . . I get the DUMB *** of the year award.

Last night I went to the pin out diagrams for the PCM to trace the B+ connections that power the PCM. I found 4. 2 that get power from the fuse box (#4 & #5) in the car and 2 that get power from the fuse box under the hood (#11).

I went to the diagram of the fuse box in the car that I had from the same manual, and looked at the #4 & #5 fuse. Diagram says #5 ignition, #4 RADIO ACCY!!!! When I originally checked the fuses I looked at #5 and #11 and both were good.

#4 was blown. New fuse, fired right up. Water probably got on something and caused a short. Everything is dry now.

 

Gotta love the "easy" fix!!

 

Well this is overdue.



Now to get it on the car.

 

Bumping this thread before it gets locked due to inactivity. Last year we moved from CO to MI which threw a huge monkey wrench into racing. This was planned, as is a house build, but in the meantime we're living in the house I grew up in which has no garage. I have access to a garage with a lift, but for now sadly racing is just not a priority. Last time I raced was October of last year, also last time I fired up the car sadly. We're about to break ground on the house though, so hopefully this time next year things are different. Seeing how I didn't load a broken car into the trailer last year, it won't take much to get it prepped.