Back several weeks ago I posted a message to the board about my "89 244 surging after a long drive. You can read about it by following this link: http://www.brickboard.com/RWD/index.htm?id=929625

I think I have it narrowed down now but I would like your opinion.

I thought the car would only surge after a long drive but it seems that it will do it anytime it is hot outside and the fuel level is off full by 4 or 5 gallons. You try to accelerate from a stop and the car acts as if it is running out of fuel. It bucks and surges and then catches up and runs pretty well.

I replaced both fuel pumps, the in-tank sock and the main fuel filter less than a year ago, none of the parts have more than 3000 miles on them. I can insert a tube into the filler neck, place it to my ear, and hear the intank pump running. When the tank i s full or it is cool outside the car runs fine. As a matter of fact, if I stop the car and wait for it to cool off a bit it will run fine for a little while. As an example: it was running very badly so I stopped at a fast food place and bought dinner (about 5:00pm). When we came out it was a lot cooler (a little after 6:00pm). I started the car and drove the next 100 mile home, the car ran fine.

My thought is a problem with the in-tank pump. The car acts as if it is not getting enough fuel to keep the fuel pressure up, thus starving the main pump. The main pump never changes sound so I think it's working correctly. When the tank is full the in-tank pump does not have to work as hard so the car runs fine. When it is cooler outside the fuel is denser (if thats a word) and the pump dosn't work as hard. As the temp goes up the fuel becomes lighter and the in-tank pump has to work harder. Does any of this make sense?? Any thoughts?? I really do need your input.

Thanks for your help.

Tony T
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Tony Turner 89 Volvo 240DL 257K, 92 Jeep Cherokee 250K, 93 Jeep Grand Cherokee 215K, 1980 Mercedes 240D 360K