Steve, Last summer my 940 did that crawling thing too only mine did not go away. Well I've seen this kind of thing before, so I told my mechanic friend who is a welder to cut that exhaust converter out and replace it. He said thats not it. I said trust me just do it. So he cut it out and low and behold something had come loose on the inside of that cheap after market converter and blocked the exit port. He welded in another one and all the power returned and it is still running fine. If it does it again have someone hold down the throttle and you put your hand at the tail pipe and see if any exhaust is coming out. Good Luck

Dear semv940,

Hope you're well. A nephew has a '90 760 (with B230FT engine). He reported very similar symptoms. He traced them to the Engine Control Unit (ECU), which is mounted behind a plastic panel, on the door-side of the passenger footwell. More specifically, after he re-flowed the solder joints on the ECU circuit board, the problem went away.

Re-flowing the solder is tedious. You need only keep the tip of a 15- or 20-watt soldering iron on each connection for only 1-2 seconds. That's all required to cause the solder to liquefy. When that happens, the solder changes color, from a dull gray to a shiny silver.

Over time, solder joints fail - they develop micro-cracks - because of repeated heating and cooling cycles. These micro-cracks are far too small to be seen with an unaided eye.

It should not be necessary to add solder. Adding solder to very tightly-packed connections means risking joining things that should not be joined.

But taking the time to reflow the solder on the ECU circuit board seemed to cure his car's intermittent refusal to run at full power, until it was shut-down and re-started.

Hope this helps.

Yours faithfully,

Spook

You did not state if this was a Regina car or a Bosch car. Either way, first things to check are the crank position sender (it's at flywheel) and the main fuel pump relay for cracked solder joints. Cracked solder joints can be repaired, there is also the fuel injector relay near the battery. But, I'd go for the crank position sensor first. Check for cracked sheath. It's easy and cheap to replace yourself. If a Regina car, check fuel pressure, but this does not sound like fuel pressure to me. CPS or main fuel relay is where I'd put my money if a betting man! Good luck.