Car sluggish and stalls out when first started - then runs OK after that

Could this be from bad gas? I put a bottle of Gum out fuel system cleaner in the tank was almost full and the directions say to put it in when almost empty and then fill for best results. My son bought gas at the same place I did and his car started having idle problems at about the same time my problems started (sometimes his engine races, sometimes normal, sometimes so slow it stalls out).

My car is a 98 Volvo S70

“Bad Gas” usually means that there is water mixed into the gas. Maybe try some of the product that removes water from the fuel system. It is usually right next to the Gumout on the shelf.

Cross your fingers!

“Sluggish when first started” leaves a great deal to the imagination. Does that mean when the car is started and shifted into gear there is a severe reduction in power and the car struggles just to pull away from a stop OR does “sluggish” mean that when started the engine does not roar to life and throw the tach up to 2,000? I get the impression that the problem is the lack of a flair up when started cold. Computerized engines have accustomed drivers to expect that turning the key with no throttle applied will fire up the engine loudly and within a few seconds bring the rpm down to normal. But I’m just reading between the lines…

mleich and Red Knox - thanks for your replies. I put in the kind of GumOut that is also supposed to remove water but no improvement so far. I just bought a bottle of Techtron Concentrate plus fuel system cleaner buit am waiting for my tank to get near empty to put it in as it says to do in the directions. This stuff does not say it removes water.

Car is still very sluggish and stalls out if I try to go anywhere when first started. After that it occasionally hesitates a bit while going down the highway and other places but not nearly as bad. Sluggishness is worst after car has been off and sitting for several hours or more. I still see a little occasional sluggishness 20-30 min after engine has been running.

Any other suggestions/ideas?

I’m usually skeptical of “bad gas” explanations for problems, though it does happen. Are you still on the same tanks of gas?

Has your check engine light come on?

When is the last time you got new spark plugs? Wires? Fuel filter? I would want to evaluate the fuel pressure, especially what it does on a hot shutdown and then a cold start.

I’m thinking bad gas because the problem literally happened over night after my son borrowed my car and put gas in it at a cheap place. Prior to that performance and gas mileage were great. I got down to about half tank when I put the gas additive in and then put in 3 gals of high test after it got down about that much as someone told me that might help.

Actually check engine light does come on. I reset it but it will come back on again . Error is: P0003 “Fuel volume regulator control circuit low.” Any idea what that means? Also, once I also got an error P171 “System too lean (bank 1)” but it never came back on after I reset it several days ago.

Spark plugs about 60,000 miles ago / 3 years
Fuel filter 44,000 miles ago / 2 years ago
Wires Not sure - it’s been awhile

How can I evaluate fuel pressure?