Yeee haaa SUCCESS!!!
As a direct result of your very helpful information, the stalling problem was traced directly to the connector for the rpm sensor. The wire spring clip, which holds the connector in place, had gone missing and as a result the plug had worked its way loose. By cleaning the pin contacts and fixing a new clip, the (new) '90 760 Turbo runs like a million! Not bad for a $750 car...
Thanks a ton!!! You guys really make the fixin' process enjoyable!!!
Craig - Wisconsin

'90 760 Turbo 197k
'86 240 DL 186k
'65 Saab Monte Carlo ?k

Yep, could well be the full pump relay, or radio suppression relay (under the hood), but as well bell housing rpm sensor; neither of which are expensive items. If the tach does not pulse during cranking, then consider rpm sensor (about $35.00), but read post and FAQ about how to replace without breaking bracket.

All the above will usually cause a fairly sudden engine stop. If you are having a slow death of the engine, then consider checking the distributor cap and rotor. Oil can get into the cap from a worn oring. Use an 8mm wrench to remove the three captive screws holding the cap. Although you might think the car will run bad all the time with this problem, this is not necessarily true, as I had this problem a couple of months after replacing all the above relays and sensors. If it is the distributor and you have oil, you can order new orings (small one and a large one are required), which means marking the position of the distributor (to re-install with throwing off timing), removing two 10mm bolts and pulling straight out.

on the two relays in the engine compartment drivers side, switch the connectors. If this solves problem remove both and resolder connections inside or replace. (mine had cold solder joints)

I also recommend that you pull the fuel pump relay and resolder.(located on relay rack behind ash tray.Access after removeing right side plastic on passenger side.
This is a very common problem with this vehicle.
Don't waste your money on new relays unless the contacts are burned off or physically damaged inside! 99% of the time it is a cold solder joint situation.

I had a similar problem with my 940 Turbo (same engine). I narrowed my problem down to the ignition because it would shut off immediately (not sputter out like a fuel issue would, and the tach would instantly drop to zero). With the assistance of the FAQ (at the top of this site) I traced it to the Ignition Control Unit. It's located under the hood, front/driver's side, mounted to the body, right above the battery.
This link will show you what it looks like:

http://www.performancemotorcars.com/catalog.php?l=wizard.jsp?partner=pmc&year=1990&make=VO&model=760-T-002&category=F&part=Ignition+Control+Unit

I could actually make the car stall by jiggling the harness going into the unit. I replaced the ICU, all is fine now.

Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

Craig,

It sounds very similar to the problems that I had with my '91 740.
It would stall at any time, any speed. I changed the fuel pump relay
and I have not seen the problem since. I would also check for loose
wires in the engine compartment. My brother-in-law has a 740 turbo
that would also stall, he found a loose ground wire in the engine
compartment. I'm not sure which one, but check any wire that is connected
to any of ignition componets. Good luck.

resolder or replace the Fuel Injection relay. Sounds exactly like my 1990 T. problem from 6 months ago. The part is not expensive so maybe just replace.