my 929 engine light flashes sometimes or times doesn't i tried use the jumper wire gnd to ten and count flashes i came up with 74 and ive found nothing and also tried several attemps to erase it and wont erase any ideas what to do

 

Chances are it is a misfire. a yellow or red light flashing is a serious cause of concern in itself, which is far more serious than a constant or steady check engine light. Check engine light flashing can be an indicator of misfire inside the car engine, which leads to catalytic converter damage, as raw fuel is being burned in the catalytic converter. If your vehicle is burning an excessive amount of fuel or misfiring, it is just a matter of time before converter failure. A constant rotten egg smell emitting from the tailpipe is a sure sign of the impending failure of your converter
Check Engine Light Flashing
Check Engine Light Flashing? Misfire Diagnosis by Autolite Spark Plugs - YouTube .
Reasons For A Converter Failure

It's definitely time to change spark plugs, wires and possibly more like ignition coil.

The blinking check engine light is indicating a severe misfire that will damage the convertor. Since you have already changed the plugs and wires, this could be a problem with the coil pack or a fuel injector. It will be tough to trace down without the problem happening though. Let me know on the 5th when you get the actual codes and we can go from there.

 

Greeneyes: Noggin puts you on the right track. Meanwhile you could have a look at the spark plugs, maybe one or even all of them are fouled. You could check the fuel pressure and you could check if the fuel pressure regulator is leaking fuel into the vacuum tube.

The 929 dates back to the eighties, so anything rubber is most suspect.

How did you try to erase the CEL? I do it by dis connecting battery negative and stepping on the brake for a few seconds. The brake light circuit drains voltage form the memories. If the light come back on right away it means the problem is real bad.
My quick and dirty google search says 74 = random misfire cyl 4

 

A bad cam/crank position sensor can throw a misfire code as well BUT they tend to be the Random/Multiple Misfire type codes and not a specific cylinder like what yours is showing. As stated by Noggin and Tan check those issues, a misfire can cause a cat-converter to overheat and start a fire as well.