92 Coupe

I replaced my intake manifold gaskets due to an oil leak. Also cleaned the engine with degreaser/water(I know, bad move). Next day the car ran fine for 10min then started to hesitate or misfire. Later on it got worse and would backfire also. So I was thinking I fried the optispark. After searching the site I found how to pull codes and have these CCM codes...

25 Courtesy lamp relay coil circuit open or shorted to ground
31 LCD data circuit shorted to battery or CCM internal open
33 Data clock circuit shorted to battery or CCM internal open circuit
35 Data strobe circuit shorted to battery or CCM internal open circuit
37 M clock circuit shorted to battery or CCM internal open circuit


I'm not sure how I could of messed up the CCM by changing the intake gaskets? Any suggestions on what could be wrong or what I need to do next? Will a bad CCM cause the engine to not run right?

Edit: Just remembered I unplugged the under hood lamps while working on the car. Would this cause the "open circuit" codes? I'm confused why there aren't any ECM codes with the engine running so bad.

 

Try this first, disconnect the battery. Ensure all is back and connected. Double check and ensure all emissions sensors are properly connected.

Check it again

Re-connect the battery and see how it goes.

 

OK, cleared codes by removing neg battery cable and hooked the underhood lamp connectors back up. Took it for a 30min drive and it ran perfect! Checked for codes and none present. Is this coincidence or did the underhood lights being disconnected cause this? I find that hard to believe.

 

PLRX typed faster than me.

I guess I can see how the underhood lamp sockets not being plugged in could cause the open circuit, but why or how would that affect how the engine runs? Guess I can unplug them again and see if it happens again for peace of mind.

Man, I paid for a $150 flatbed tow too!

 

Engine problem is back! After letting the car sit about 30min I went to start it, and the thing is running terrible. It is almost 100 degrees out, so the engine was still hot. Seems like a bad misfire and gets worse with the AC on. Stalled it while backing out of the drive. Started back up enough for me to pull back in. Car isn't showing any codes though.

Optispark or ???? Please help guide me.

 

I'd guess opti also.....they do not like water.

The hood lights definitely have nothing to do with your problem. I've had mine unplugged for 10+ years.

 

Depending on what you sprayed with the water and degreaser, it could be a whole host of things.

Although you likely didn't remove them, verify all the plug wires are fully seated. You might also pull the wires off of the #1 and #2 cylinders and ensure there's no dampness inside the boots (doubt it, but it's a quick easy check).

Next, pull the harness that runs from the intake to the opti and ensure all those pins are dry / not corroded.

Check the coil wire from the coil to the Opti...makes sure it's dry and it's fully seated.

Lastly, make sure all the injector connectors are fully seated/not loose.

If all of the above "pass", I'd lean towards the opti being wet inside. You may be able to get by with removing the cap and drying it out using a little compressed air.

 

Thanks for the help.

Everything has checked out except I still need to check the intake to opti harness. I couldn't find it so I have to look up where it is.

The opti is covered in oily grime from the manifold leak.

 

Passenger side of the intake, runs forward and down to the Opti. When disconnecting from the Opti, be careful to not break the locking tab on connector.

Never a good sign. Nonetheless, pulling the cap and cleaning/drying may still be all it needs since it ran fine before. You'll also need to clean the optical sensor and wheel (easily accessible with the cap and rotor off). Use electrical contact cleaner to do this.

 

In order to remove the opti cap, the water pump needs to be removed, right? If I'm going that far, should I just swap out the opti with a new one? I plan to sell the car soon, so I want things to be right. Car has it's original optispark with 61k miles.

One thing I'm finding out is new Delco's are near impossible to find. Delco is now selling remanufactured units under the same part number.

 

Just depends how much you want to spend. If it was running fine, there's no harm in just cleaning it up/drying it out.

 

Son of a!!!

Finished replacing the Optispark today. What fun it was beating the balancer off for an hour.

Took it for a short test drive and it seems to be running better, but it now isn't idling smooth like it should. Idle is surging about 100-200rpm and it just isn't running real smooth. No codes present.

If I take it to a shop, do they have more detailed scanners that will give more info than me just checking for codes on the dash? I don't want to keep throwing money at it not knowing exactly what is wrong.

 

OK, did some more digging. It seems to me that not all the fuel injectors are working right. Most you can feel "clicking" but there's a couple on the passenger side that you can't fell anything. Next I took a mechanic's stethoscope and you can hear a distinctive clicking on all but the couple I don't think is working. Finally, I pulled the connector on them and the idle didn't change, but when I pulled the connector on a good injector the idle did change.

How do I determine if it's the actual injectors or whatever controls them? Computer still doesn't show a code, even with me pulling some injector plugs.

 

Searching the forum I learned about the injector ohm test.

Seems I have 3 bad injectors. My ohm readings..

12.9
12.7
0.4
12.8
4.1
12.7
7.3
12.8

Ordering a set of the Bosch 3's from FIC. Will post results once I get them.

 

FIC's injectors did the trick! Car is now leak free and running great!