d-law

Yesterday I was checking the fluid level for the clutch on my 1991 C4. The vehicle was running and when I snapped the Computer Control Module back into place the care died and now it will not start. I am guessing it is a problem with the CCM, however I/m not sure. Any information would be a great help.

WVZR-1

Your terminology is flawed a little. That's actually the ECM (Engine Control Module) that you had to move to get to the master. Do you have a "crank and no start" OR do you have "no crank also"?

You've undoubtedly either pulled a wire/terminal loose from one of the four connectors. Did you have any of the connectors actually removed to gain access or did you just lift and twist to get out of the way?

d-law

The vehicle will crank but not start. No wires are plugs were removed. All I did was lift and twist the unit out of the way. Vehicle was running fine until it snapped back into place.

WVZR-1

Do you have a SECURITY light in the cluster? FLASHING OR STEADY ON if you do? It was running when you put the ECM back into the tray?

d-law

I think the light was flashing, but I/m not sure. It will be later today before I can make sure. The car was running.

WVZR-1

I've never had a FE (Fuel Enable) problem but with what you mention I'd do these 2 things. 1. Do you hear the fuel pump run "momentarily" with KEY ON? 2. You might pick up a fuel pressure gauge rental from a local AZ. If you don't hear the pump or you don't get fuel pressure to the gauge with KEY ON or while CRANKING it might help pin point which wire/terminal is creating the issue.

I'm going to guess you don't have a FSM (Factory Service Manual). Do you?

Do you know how to use the fuel gauge connected to the fuel rail?

d-law

I don't have a FSM. I do know how to use the gauge. I just bought the car and haven't had a chance to get a FSM. Could the ECM have gone bad or something inside it come loose or broke when i was putting it back in place.

kenpeindl

Just a hunch but I am wonder if you loosen the memcal prom chip inside when you snapped the module back in to it holding bracket. Lift the ECM our and turn the it over and remove the rectangle cover to check if the memcal chip is loose or unplugged. Like I said it's just a hunch.

Ken

d-law

I will try that, thanks.

WVZR-1

The PROM if installed correctly is quite secure. Now if someone has added a PROM that uses a "hang-on" it's maybe possible that it's the issue. I'd say unlikely. Lifting, twisting and turning while you were there I'd think the issue but you could do as suggested in a previous post. I wouldn't do it for a start.

Do the fuel pump "listen", the fuel gauge check with KEY ON and while CRANKING after checking the SECURITY light and noting it's state. Do you have maybe a CEL/SES in the DIC with KEY ON and it's done with the BULB CHECK?

d-law

English please, LOL.. I/m not sure what your talking about, CEL/SES and DIC?

WVZR-1

CEL - Check Engine Light, SES - Service Engine Soon, DIC - Driver Information Center

The reason I like the checks I mentioned first vs checking the PROM is that they could be considered "NON DESTRUCTIVE". Lifting. twisting and turning got you where you are, doing again if someone has already been in the connectors to the ECM might actually make it worse.

Read this and maybe check the CCM (Central Control Module) different location in the car and maybe you've actually set a CCM Code 54 that would indicate an FE problem. That might help if it was as to which pin to check at the ECM.

http://tech.corvettecentral.com/2011...trouble-codes/

Of course check all fuses paying attention to FP1, ECM and maybe the CCM fuses. Fuse box if you don't know is on the end of the dash after opening the right door.