940 Missing

[empomire]

I have a 1997 940 classic LPT. After about 20 miles, under acceleration when I get to 2500 revs it starts missing, the rev counter flicks off and on also. If I get to 3000 revs it gets better, then a bit more and it can cut out completely, rev counter to zero although the engine is still turning, engine fires up and rev counter comes back if I lift off the throttle. Been for a diagnostic at the main dealer but of course the fault was not present. Any ideas, and thanks for looking.

[NI_Volvo_Nut]

Check for bare wires on the TDC sensor at the top of the bellhousing

[arcturus]

Is it manual or auto? If auto the speedo could be the problem

[empomire]

Originally Posted by arcturus

Is it manual or auto? If auto the speedo could be the problem

Manual. I should have mentioned that the waste gate actuator rod is disconnected, the waste gate is in the position as if the rod were fully extended. Is that open or shut? Will look at the flywheel sensor wiring, but why is it only on heavy acceleration (or towing the trailer uphill)? When I lift off and cruise under light throttle all is OK? I know the fuel pump can cut out if turbo pressure is too high, but that wouldn't cut the tacho, it seems to be losing ignition. Thanks for your input.

[empomire]

When I shifted the wires to the flywheel sensor things got better for a while, until a very damp day. Took the sensor off, the outside insulation was gone, third uninsulated core exposed, and the white wire was kinked and parted at the first tug. Running well under temp repair, new one on the way, £35.