1991 Volvo 740, non-turbo, regina system.

2 years ago replaced the fuel pump.

Car never ran right after that but it ran.

2 months ago, would hardly start at all, and husband barely got it home. Engine light was on. Googling gave me the info as to how to check codes. It was throwing a code for the Air Temp sensor and O2 sensor. Both those were replaced. All vacuum lines were checked and/or replaced. MAP sensor was replaced. Cap & Rotor were replaced as well. Plugs and wires looked fine and had been replaced recently. During all this replacement...car would run some but would stumble and have no pick up/be sluggish and would have a gassy smell in the exhaust and it would backfire into the air cleaner box, the box would actually move from the pop when it backfired.

But, After replacing all of those above, it seemed to being doing some better, but still not right and then went back to the no start issue as well as the other drivability issues.

Googling again, found some info about doing "limp home" mode and if it ran fine above 30-35 then it was likely the Fuel Pressure Regulator. Today we replaced the Fuel Pressure Regulator. It started up fine. Ran fine. Husband drove it around for 10 mins and it was fine.

Several hours later, went to go pick up daughter and car will not start. Cranks, but acts as if not getting fuel. Tried "limp home", no luck. At my wits end with this car and VERY frustrated. Please help!!!