So we have a Volvo 740 with 230FT engine, 1988 in our highschool automotive shop. I am not very well trained in the art of diagnosing electrical system problems. We had it running, it sat in a warm dry shop after sitting outside for a year. We brought it in, started it, then left it for the spring break. Returned to no spark. We did a test on the Coil, it did not match the manual specs so we replaced it but it still has no spark. We have checked the distributor and made sure its all clean, checked the wires to make sure they are ok, but still no spark. Can anyone help guide me to whats next. There is confirmed to be 12 volts making to to the coils primary terminals.

 

I believe you have a Crank Position Sensor mounted on the top of the bell housing. It is below the rear distributor cap. Check the wire and connector. It may need to be replaced. It controls the spark.

 

A hall sensor in the distributor provides timing on a 1988 (LH 2.2)

the hall sensor goes to the ICU (ignition control unit), which I believe is mounted behind the dashboard. the ICU sends timing pulses to the power module on the left fender, and that in turn fires the coil via grounding coil pin 1.

take a 12V test light, and go looking for those timing pulses at pin 1 of the coil when you crank the car over.

(the crank sensor jagtoes mentions was used with LH2.4 on 1989+ models).

 

I cannot find any sensor on the bell housing at all. I will check again.

 

kmcghee; thats because there is no crank sensor on LH 2.2 cars like yours, CPS (Crank Position Sensor) is used with LH 2.4, on 1989+ non-turbo and 1990+ turbo only.

as I said, you have a hall sensor in your distributor as the timing source. I would start with looking for timing pulses on coil pin 1 with a 12V test light while cranking. if you do NOT see them there, then look on the input pin of the ignition power module, I believe its pin 5 on the power module. this power module is a flat rectangular 5-pin thing firmly mounted on a bracket on the left fender, the bracket serves as a heat sink for it as they get warm.

 

Problem solved, there is a box beside the battery that I guess became unplugged when the students took the battery out, plugged it back in and it runs like a top.

 

if thats a small flat thing, about 3" across, thats probably the ignition power module.