Intermittent stalling

maxnix · Post by **maxnix** » 30 Aug 2023, 17:31

I did something dumb. I left my ignition switched on overnight. Now the engine stalls randomly and today the check engine light came on which is newer than the stalling. Not sure where I should start with tracking this down. Other wise the car runs smoothly with plenty of power.

thanks
Max

mechanic · Post by **mechanic** » 31 Aug 2023, 21:02

Hello- so with the ignition on for seveal hours- the battery "died" , right?
What model engine is there installed in the year of Volvo?
Some white blocks ( and the red block engines too) the IAC valve operates a soon as the igintion is turned "on".
The AMM on the red blockks heats up when the ignition is "on". The fuel pump is on also- On the red blocks the radio suppression relay is on- It colud be that the RSR is cooked.
Did you check MIL or the ODB ?
You would have to do a relay/sensor check on the OBDll or use an scan reader on the newer Volvo,depends on the year.

maxnix · Post by **maxnix** » 02 Sep 2023, 11:25

Yes ignition left on killed the battery
.
Its a 92 740 wagon, turbo redblock auto transmission

Someone suggested it could be the ignition amplifier which I think is the AMM you referred to but I haven't fond a way to test it yet. I would like to know that is the issue before I buy a new ignition module.

I haven't looked into the radio suppression relay yet.

Does the intermittent stalling, starts right back up and runs great otherwise help to narrow it down at all?

I dont have a code reader and my local autparts store only reads OBD 2.

Thanks for the suggestions

Post by **chrism** » 04 Sep 2023, 16:38

You car has the OBD I diagnostic system. Read about it via the link below. You retrieve the fault codes through the little box somewhere around the LH strut tower. No scan tool is required. (Your car has the Bosch fuel and ignition systems, NOT Rex/Regina. The OBD can store up to about three fault codes. There are also two sockets to check in the read/out box - one for ignition and one for fuel.

https://www.brickboard.com/FAQ/700-900/ ... DCodes.htm

maxnix · Post by **maxnix** » 09 Sep 2023, 12:24

Thanks Chris, I'm going to educate myself on how to read and understand the codes.

maxnix · Post by **maxnix** » 19 Sep 2023, 19:25

I replaced both the radio suppression relay and the crank position sensor and one of those items seems to have been the problem. My money is on the crank position sensor, the cable insulation was damaged. The link to the explanation of the built in diagnostics is a gem! Sadly I had already disconnected the battery so any codes had been wiped. Next Time I will do that first.

Thanks for the advice!