740 fixed, now 1991 940 turbo hesitated and almost quit while wife driving yesterday. Not accel or decel related, happened under normal driving conditions; randomly for about two seconds at 1 or 2 mile intervals. About 6 months back I replaced the fuel pump relay and radio suppression relay. Just before that I told a mechanic to replace the rpm sensor while diagnosing an intermitant no start problem which I found to be the rs relay after he could not fix it (I hope he replaced rpm sensor - he's out of business now).

I'm thinking lose wiring or rpm sensor related. Car starts fine. Any ideas?

I'm thinking ignition module.

Ignition module as in power stage? Did wire wiggle and relay knock test and no problem. Took for a drive and no problem. Plenty of zip cold or hot. Have however had occasional problem when giving considerable gas it boogs down on me until I let up on the gas.

Have 200,000 mile on it and have never change distributor cap and rotor, injector orings or fuel pressure regulator. Therefore, going to do that just for preventative maintenance and hopes that it will help.

Thanks for you input.

Sounds like it might be the fuel pumps themselves. Any noise coming from the main pump under the driver's seat? Check both that pump and the in-tank pump, if one is failing it will put strain on the other, and if one dies altogether you'll have a no-drive situation. As I found in the middle of nowhere, Nebraska this summer.

jeff daigle
'89 745GL 135,000mi

Only thing is Jeff car runs great otherwise. Like said in my post to John, took it for a spin a little while ago and no problem. Pleanty of power cold or hot. Kick in the turbo and she off like nothings wrong. It's just an unpredictable thing.

I guess I should check the fuel pressure anyway since this is these are orginal pumps with 200,000 mile on them. As also mentioned to John, as preventative maintenance and in hopes of helping I am replacing dist cap and rotor, fuel pressure regulator and injector orings since they are also original.

Thanks for the help. I'll check for the pump buzz and that fuel pressure.

Yeah, that's the thing about fuel pumps. I had an '87 740 that went 225,000mi on the original fuel pumps, then I had to replace the in-tank pump on my '89 740 at 133,000mi (though it's my theory that some oxygenated gas helped it along). There was little warning before it died--two instances of the loss of power you described, then one day about 2 weeks later I noticed the main pump was buzzing, and about 5 minutes later the car died & wouldn't start until the in-tank pump was replaced.

Thanks for the warning. Both my volvo's are almost there.