89’ IROC-Z 350TPI 100,000mi No major Mods.


Went to start car the other morning and fired up, stumble, and stalled… Ran perfectly fine before this happened.

Symtoms:

-Engine Starts for 1 sec. and stalls
-Engine runs rough when lightly pumping gas (too much gas it dies, not enough it dies)
-Significant amount of black smoke
-Engine ran normal one time I was able to pump and hold gas at 3000 rpm as soon as I let off gas… shaking, misfire, backfire, sluggish, stall.

Tested:

TPS – in spec. function proper
EGR – Function Proper
EGR Solenoid – Vacuum / light test fine

-Disconnected MAF and Knock Sensor and no change also no trouble codes.

-After repeated starts and trying to get the car to set a code, the engine no longer even fires just rotates.

-Removed cap and rotor, found that moisture has gotten in, the top of the distributor (3yrs old) has a lot of rust, and green substance on each diode in the cap and on the rotor.

-Can a bad cap and rotor shut an engine down without any previous signs it is going bad?

-Does the car actually have to run to set a trouble code?

Also I found that my positive bat cable has been significantly burned by my headers

- Possible arc? Would the car have run at all if the arc had damaged the ECM?
- What about timing chain slipping? Worn Nylon.

 

Check the fuel pressure and hope it's the fuel filter and not the pump...

 

thanks sup42...I can't remember what the spec is suppose to be...I will keep searching if you know it please reply...I checked the pressure and with ignition on I get 40 PSI and since I can't get the car to idle I get it bouncing back from 40 to 46 PSI while I crank the motor over. It almost sounds like it wants to start when it bounces to 46 PSI.

 

Ok...fuel pressure is well within its limits...I can get the car to idle rough for about 5 to 10 sec. but when I disconnect the EST it doesn't seem like I am getting any spark at all or atleast it doesn't fire. I know cause I just tried it, when I bypass the EST in my truck it still starts up just fine...so why does it change in my car.

 

If you have access to a timing light, try this: Connect the timing light to a plug wire and see if it flashes when the engine won't start.
This will show if there is low ignition voltage or if the high voltage distribution is breaking down.
It's like taking the 50/50. Is it fuel or ignition?

 

I am thinking black smoke ...pig rich ?????


So there are a few things it could be ...emphasis on " could be "

CTS is shot ...ECM thinkit's really cold outside and cranks the fuel to it
EST ... timeing off because of faulty EST


... I am sure others will chime in with other stuff for you to look up aswell .

 

Thanks all for the input. After testing everything I could think of on this car I got p--sed off and just turned the key and kept hammering on the gas pedal and finally I got a trouble code. (code 42) ignition mudule. I disconnected it and sure enough corroded connectors. I Just happen to have one sitting around in the garage...plugged it in and vroom vroom...we have ignition houston. Well all I need to do is pull out the fouled plugs reset the timing and change the oil and we are all good.