I have a 1990 780 bertone, 4 cylinder Turbo, purchased with 27,000 mi, currently has 154,000 mi. My problem is this: Nearly every time that I drive the car, I can expect the engine to die in about 5-7 minutes. When it dies, there is no hesitation, sputtering or the like. All of the warning indicators on the dash come on, as if the ignition was turned off and back on without starting. I pull over to the side of the road, after waiting for several minutes, I can re-start the car and usually continue for the rest of the trip. If the car is shut off for a considerable period of time, I can expect the cycle to repeat itself. Can anyone share any hints as to what the problem may be? When the car is running, there is no indication of performance problems, tune up issues or the like. I have owned volvo's since 1982, and have experienced a few quirkie problems, but I really need help on this one.

Thanks, Larry T.

If you'd like to try out the "swap the coil" idea, I've got a stock coil out of my '91 780 you're more than welcome to have for the cost of shipping. I've also got an incomplete set of plug wires and a brand new set of 6 spark plugs you can dick around with if you'd like to throw in a few extra bucks. Personally, I'd start looking at the ignition switch. How much crap do you hang off your keychain? If the contacts in there fail intermittently (i.e. after heating up a bit?) that may be the cause for the mysterious "looks like someone turned the KEY off and back on again" symptom. Email me if you're interested in the spare parts.

Good luck,
-Jon
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1LT Jonathan T. Belmont-- '91 Coupe 164K "Gustaf"

Hi Jon,
Thanks for the ofer on the coil. I just learned about the OBD1 system in the car. I am in the process of reading the diagnostics this week in my spare time. I am hoping that the diag. indicate that there was a missed signal from the RPM sensor. I am thinking that if there is an open in the sensor, that it would cause this problem. The ignition switch is also a good thought. I don't have a bunch of 'crap' as you put it, on the key ring, simplly a keyring and the ignition key. Occassionally, actually quite seldom, when the car dies, and before I come to a complete stop and shut the key off, it will try to restart. I can here the starter solenoid engaging into the spinning flywheel.

Regarding the use of your coil, if you have any idea on the freight cost, I can send you a check and my address. That couldn't hurt to try it out. Why did you replace the coil in your 91?

Thanks for the help.

Larry Thompson

I replaced the coil b/c I got one from torquemaster when I bought their plugs. Any difference? I dunno... maybe money well spent mebbe not. At any rate, the stock one is perfectly good. I'm guessing about $5 for the shipping via USPS priority mail. Drop me an email at sirexcel@aol.com and I'll send you my address or you can paypal me at that same address.

-Jon
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1LT Jonathan T. Belmont-- '91 Coupe 165K 'Gustaf'

Hi Larry,

Sounds like a nice car - i'm well envious!

Just a small thing - once you've checked all the basics have a look at the ignition coil. Substitute it for a friends coil or even buy a new one as they don't cost a lot and it wouldn't harm to replace it after that mileage. A distant accquantaince of mine with a 940 LPT had the same problem and it turned out to be just that. As it cuts out instantly with no spluttering then i'd be inclined to think it's an electrical fault you have there.

Good luck,

Big Rich.
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This is a 245 Volvo...the most powerful wagon it the world...d'ya feel lucky Punk?

Read-out the fault codes per the "OBD" section in the 700/900 FAQ's on this site. It may give you a clue.

Have you resoldered the fuel pump relay? Have you resoldered the radio suppression relay?

Not familiar with the 780 but if it has a tray of relays under the ashtrays like other 7xx cars you should find the fuel pump relay there.

My 91 740 turbo has the two identical relays (one of which is the suppression relay)mounted on the shock towers (one on each side)

The ones on the shock tower (or where ever you find them) will have a silicone seal on the joint between the base and the cover. Remove the silicone and remove the cover- resolder the board. Look with a magnifying glass for imperfect solder joints; but go ahead and resolder them all. Same procedure on the fuel pump relay.

Also could be the rpm sensor located on the top of the bell housing. When the car dies does the tach still register. If not I would suspect the rpm sensor. I don't know of any way to test it.

Randy