Q: I have a 1986 Volvo 740/ 4 cyl. My car runs for about 7-10 mins, and then it stalls out. I have a full gas tank, i got a tunip done, IT RUNS WELL AT FIRST but then it stalls out.
A: will it re-start and stay running if you feather the gas pedal?[possible throttle body carbon ring or constant idle motor problem] if it wont re-start until it sits for 20 min. or so [you may have a failing fuel pump and/or pump relay] when it stalls out and if it wont re-start and you smell raw fuel in the exhaust[you may have a failed coolant temp sensor] if it stalls and restarts and will idle but stalls again as soon as you touch the gas pedal. [suspect the air mass unit]-- this can be tested by unplugging the quick disconnect at the air mass unit, this will force computer into limp home mode [if now runs poorly but quits stalling replace the air mass unit] note acceleration will be very slow with the air mass unit disconnected. one last tip there is a radio suppression relay [right strut tower turbo left strut tower non turbo] this supplies power to the injectors [12v].intermittent failures are fairly common but does not really fit your described symptom in short you will have to be more specific for proper help. is your car a turbo model? does it have a manual or automatic transmission? please list actual tune up parts that were changed, serviced, or cleaned. NOTE cod_frag 's tip for the distributor is stellar. i have seen many over the years fail like this. caution is to be used when replacing the distributor cap on these models the plastic is very brittle.