Hello Everyone,

I have 1988 745 turbo with hall sensor and Turbo + package. 190k mi on the car. I am getting tired of getting stranded on the road - this is sixth time this car has done this to me in two weeks. This time, It did not start even after cooling down for a hour.

Please, please help me with this issue.. I have tried Everything that I could do according to the FAQs on the site, and YES, I have used the Search.. Please, help me..

[ there's summary on the end of this question ]

last time the car stalled out on me, it seemed to be the hall sensor. Reminding me of what I have read on the forum, it had to be the hall sensor. So, I pulled off a distributor from a 1986 744t sedan with 270k mi (yes VOLVO durability lol- ) and cleaned it and gave the new bracket for the hall sensor connection on the side of the distributor. At the same time, I also replaced the ignition booster too. (right beside the battery, the small Bosch module cooled by heat sink on the body)This module was loose on the mount, so it could have been overheated, causing the stall from the first place.. anyways, the car seemed to be running fine for a while.. I was able to drive the car for 40kms - which proved that everything were all right.

Then the disaster came.

This time, my car stopped right after exiting a highway ramp. I took the ramp at 55km/h (or 35mph) shifting my car 4-3 then 2 for engine brake. The rpm had reached something like 4000 rpm, then I took the corner. I suddenly saw.. a dead RPM gauge with flash dashboard like engine had stalled out, but a running engine. So I quickly pulled over to the side and drove the car on to the shoulder. I waited a hour for it to start up, and I also tried gently tapping on the ignition module and the distributor. It did not work.

I had towed it home, which cost some $60 even if it was like 3 miles away from my home.

Wondering if it is the bad connection, I took off the distributor and looked at the hall sensor connection, which seemed to be fine. so I blew both side - the distributor side and connector to the hall sensor with compressed air and connected it back. It did not start up. There's fuel getting to the engine, but when I crank the engine, the RPM gauge does not move at ALL. I also tried swapping the ignition booster to the original one, but no luck.

I will be replacing the hall sensor and distributor seals on the original distributor( in my hand right now), and will try this again. I guess I am locked down for few days until the mechanics start to work.



Summary:
1. Replaced distributor( hall sensor) with 260k mi on it
2. Ran fine
3. Stalled out on me , registering 0 rpm while the engine running. cranking.
4. There is fuel getting to the engine. Pump relay, Radio surpression relay, fuses - all check with relating to the fuel
5. No starting even after 6hrs.
6. Help me!

Maybe, this is coincidental problem with all the hall sensor.

Suspected Culprits are:
1. Hall sensor
2. Wiring Harness
3. ECU

Please, Please help me on this issue. I am very stressed out with this issue.!

Thanks so much..

Happy new year - Alex