"hot flashes", speedo problems for 1991 740 turbo

Post by **sseir39** » 23 Oct 2007, 12:58

Having owned more RWD Volvo's than FWD's most of these things happen with aging. The speedometer head is most likely bad and you can pick up a good used one inexpensively. Our 91 940 SE would be going 85 miles without the engine running. Another thing to check is the sender (electric) on the differential housing. The wiring at the sensor sometimes goes south.

The engine cutting out can be a number of things and there is a good trouble shoot guide on brickboard.com (RWD section FAQ).

You will probably have more input.
Good luck and have fun.

eyyu · Post by **eyyu** » 25 Oct 2007, 12:40

sseir39 wrote:Having owned more RWD Volvo's than FWD's most of these things happen with aging. The speedometer head is most likely bad and you can pick up a good used one inexpensively. Our 91 940 SE would be going 85 miles without the engine running. Another thing to check is the sender (electric) on the differential housing. The wiring at the sensor sometimes goes south.

The engine cutting out can be a number of things and there is a good trouble shoot guide on brickboard.com (RWD section FAQ).

You will probably have more input.
Good luck and have fun.

Thanks, SSeir39. Here is more I did and found out:

1. pulled the IACV, pretty clean, cleaned again anyway and the hose. Just want tomake sure that I got the right thing. It

wojeepster · Post by **wojeepster** » 25 Oct 2007, 15:37

The speedometer always jumps when you first start the car to show you there is power to the coil. When your car dies and you restart this is why it is jumping. Find out why your car is stallling or why you have an intermittent no power, that will take care of the speedo.....

eyyu · Post by **eyyu** » 25 Oct 2007, 18:51

wojeepster wrote:The speedometer always jumps when you first start the car to show you there is power to the coil. When your car dies and you restart this is why it is jumping. Find out why your car is stallling or why you have an intermittent no power, that will take care of the speedo.....

THanksv for your opinion, wojeepster. The speedo does not always do this, yet often. It doesn't just jump once when I put the key to the on position, it actually dances continousely untill car moves over 20 mph, then it will indicate the true speed. I'm still working on the sudden stalling issue. Isn't it fun to have to tackle so many little, yet anoying problems with those ultra reliable Volvos! Erwin