I found this car which was sitting for couple years. Bought it, charged the battery, fixed few other things and off and running. However, after running the car for 30-40 mins it will all of a sudden just quit. It's a standard shift and even when in gear the tach shows zero rpm, all ignition is shut right down. If I recycle the ignition key it will fire right up, but usually for only couple mins and then repeats itself. It never does it until the car is up to temperature, but the temp gauge is never overheating... If I let car sit for couple hours, it will run for 30 mins again without repeating.
The battery I just charged, I didn't change it... It always seems up and able, but someone told me I should change it... I can't see how this would affect the ignition, but that will be my next step. Does anyone have any insight? Ideas?
Any help would be appreciated
Thanks
Tsebast

 

If you post the model year of the car, it may help in diagnosing. From the sounds of the symptoms, you may have a failing crank position sensor. But only 740 turbos from '90 on have the CPS.

 

My 740 would randomly die when the battery was old and weak.

It sounds like you have an issue with cap and rotor.

 

Sorry about that, it is a 1990 740 turbo
Thanks so much for the help!

 

Is the crank position sensor easy to find and replace on this model? Yes someone else said battery, I will also change battery.... Even though I really thought it was ok...
Thanks again for your input!

 

rather than change the battery, check it with a volt meter, both before you start the car, and with teh car running. a fully charged battery should be about 12.6V with the engine off, and when you start the car the alternator should bring it up to about 13.8V charging voltage.

the CPS on a 1989+ non-turbo and 1990+ turbo is behind the back of the head, below and just to the left (drivers side) of the distributor... its stuck into the top of the bell housing where the transmission joins the engine, and is reading notches in the flywheel or flexiplate.

 

I wouldn't go changing the CPS quite yet. The only thing that goes bad on the CPS is the wiring on it. It is a thick round black cable - kinda like coax cable. If it is cracked and insulation is falling off, then replace it. Otherwise, there are plenty of other things to check before replacing items.

 

Local shop says it is ignition computer..... Volvo doesn't make part, and we are trying to find used one.... Anyone have an opinion? Think this is viable problem? Any comments would be appreciated...
Thanks

 

the EZK ignition computers are usually pretty robust. the power module is more likely to go out, but without knowing the shop's chain of tests and conclusions, its impossible to outguess them.

afaik, you can use the ICU from any 240/740/940 1990+ although if you have EGR, then the ICU has to be from another EGR car.