Hello first time poster long time lurker. I just purchased a 83 245 and having a no start issue.
the issue is after turning the key the pump is not turning on and the car will just crank.
I went ahead and checked the fuel pumps by jumping correct fuses and both pumps are working.
I replaced both the relays to do with the fuel pump and ignition. still not working.
I jumped on both relays the 30 to 87 and the car fires right up and runs... but idles at ~2500 rpm
if i jump just the fuel pump relay and leave the other relay plugged in i get the same result, running at ~2500 rpm.
I un plugged the MAF just to see what would happen and it ran at a rough 1500 rpm.

I checked the throttle body and idle is correctly set, all vacuum lines are in good shape.

Ive traced wires and all seem to be in good shape and appears someone at one point replaced the harness.
Im assuming my ecu has gone bad. both my other volvos are lh 2.4 so i cant swap and check. it does have a bosch 0 280 000 503 ecu.

If anyone has any other ideas that would be greatly appreciated.

thank you!

 

The replacement harness would be my first concern!

Did the car run OK after the replacement and then go bad at some point, or did the associated wiring caused problems continue or worsen?

ECUs are blamed for too many undiagnosed issues but they are rarely the cause.

 

I bought it a week ago so this harness was done before my ownership.
without jumping the relays, I get no response or click from the relays. It seems to me there is no signal to the relays to open or click on. bypassing that with a jump from 30 to 87 runs the car.
these are brand new bosch relays I just got in.

 

Update:

Replaced the ECU with a known good one (ebay) and fixed the problem. Car runs great.

Hope this helps anyone else with a similar issue.

Thank you.