z06scentair

Good Deal

Hope this corrects the issue.

Dynomite

Keep us posted on the re-installation
And.....I am assuming they will repair 90' through 95' ZR-1 ECMs as I think only the chip is different

ECM Interchangeability TIPS

DZielinski

Yes. Same price for 90-95 ECU repair. Just the part number is different.

z06scentair

Cliff,

If indeed it does solve, this should be a sticky add to your tech tips on the Net.

Brad

Dynomite

Yep....but will wait to make sure

And....if in fact they found Numerous bad solder connections I would assume this is NOT an isolated case. Unless someone was trying something new on the ECM with a soldering iron

z06scentair

Any Update?

DZielinski

Sorry for not updating the thread recently. I received the ECU last week. Installed it back in the car, but still no spark to any of the spark plugs when the engine is cranked. I cranked it over for about 5-7 seconds with no spark at the plug. I have the DIS remounted back under the top of the manifold with the 4 screws and enough compound for good insulation but I only have the top of the manifold screwed to the bottom with 4 screws as I did not know if I would have to remove it back to get to the DIS again but wanted to make sure I had a ground connection from the engine to the top of the manifold and the DIS. I did not see any separate ground wires that looked like they should be connected.

z06scentair

No more grounds that I can think of. Did you verify the connections in the rear of the module? They pulled up tight and no bent pins?

Also pull the memcal back out of the computer and turn it around, try and crank again.

DZielinski

I will check for bent pins to the DIS module, but I can't open the CPU box because it has a "warranty void if broken" tag on it after it was repaired.

z06scentair

I would open the memcal door and verify it has the correct prom for your car. ZR vs. Standard are different.

DZielinski

what is the memcal? The car ran fine until it died so I don't see how it could have ran ok before if it had a wrong prom.

z06scentair

Just wondering if during the repair it was changed.

Dominic Sorresso

Turn the ignition to ON, not Start. Note the Service Engine light. Did it flash ONCE and then stay on or does it flicker?
The ECM actually has nothing to do w the start sequence. The DIS handles getting the motor to 400rpm, then hands off spark control to the ECM once that is reached. Do you show oil pressure when u crank motor?

DZielinski

The battery is low so it is hard to crank, but here is what happens.

-When I open the car door the SECURITY light comes on and starts flashing.
-When I put the key in ignition SECURITY light goes out.
-When I turn the key 1 position the SERVICE ENGINE light flickers 1 time then stays on.
-When I crank the engine, there is no oil pressure for a few seconds, but it eventually builds up and starts indicating oil pressure on the gauge. By the time the oil pressure gauge starts indicating oil pressure, the starter starts slowing down and the dash lights go out as the battery is dying. I used a fast battery charger/starter to crank it over.

Dominic Sorresso

Looks to me that ECM is working. I would definitely replace the battery at this point.

blownrunner

Do you have the factory service manual? It will have a troubleshooting tree for your spark problem. I do not know how to work on these cars without one. OBD2 is more universal, but these OBD1 systems were different for every manufacturer.

In the past, I have left a plug disconnected under the plenum resulting in a no-start and the engine just cranks. There is also a diagnostic plug by the master cylinder to do some basic troubleshooting. It is there so you do not have to remove the plenum to troubleshoot.

DZielinski

Does this mean that in a start condition the DIS is the only device that would fire the coils and the plugs? If that is true, then the DIS must be my problem. Thanks.

DZielinski

I have the Electrical Manual but no service manual. Is one available somewhere on the line? Thanks.

Dominic Sorresso

The DIS controls startup. If it isn't starting then either DIS or something that signals the DIS to start could be the culprit.

DZielinski

Thanks. I will continue to look for a DIS module or see if someone can repair mine.