1993 Volvo 850 gas?

hey I had the same problem with a car, I would check the air intake ( the big black rubber hose coming from the air filter housing to the intake of the car)for a crack even just a small one would cause a problem like that,it could also be a problem with a vacum line

[quote:e571203fbb="rick h"]Engine Performance problem
1993 Volvo 850 Two Wheel Drive Automatic 118000 miles
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I have a 5cyl 93 volvo 850 on accelaration it hesitates but as soon as you let off gas pedal and slightly push it down it will gain speed. There are no codes that show up using under hood factory code reader. (1-1-1)I have replaced fuel filter,replaced fuel injecters, the exhaust is not plugged. fuel pressure is at 45psi?the distributer cap is fine as is the rotor. It will cruise a long time at highway speed but as soon as you push down on gas pedal it will hesitate until backing off and feather light acceleration will get it up to speed. It does this at any speed.A mechanic friend has checked out mentioned stuff above. It idols fine but also hesitates on acceleration. Any ideas on what do to next short of going to volvo dealer and opening my wallet? thanks rick[/quote:e571203fbb]the problem was a fuel pump it would have low pressure during driving speed. thanks to lumlumsweetie for trying to solve. rick h

Hi rick h,

Did you test the throttle position sensor?
A faulty O2 sensor would cause what you described and does not show on the CEL.

A diagnostic test would be necessary to check out the readings under load.

[quote:86f5995cc8="rick h"][quote:86f5995cc8="rick h"]Engine Performance problem
1993 Volvo 850 Two Wheel Drive Automatic 118000 miles
----------------------------------------------------------------
I have a 5cyl 93 volvo 850 on accelaration it hesitates but as soon as you let off gas pedal and slightly push it down it will gain speed. There are no codes that show up using under hood factory code reader. (1-1-1)I have replaced fuel filter,replaced fuel injecters, the exhaust is not plugged. fuel pressure is at 45psi?the distributer cap is fine as is the rotor. It will cruise a long time at highway speed but as soon as you push down on gas pedal it will hesitate until backing off and feather light acceleration will get it up to speed. It does this at any speed.A mechanic friend has checked out mentioned stuff above. It idols fine but also hesitates on acceleration. Any ideas on what do to next short of going to volvo dealer and opening my wallet? thanks rick[/quote:86f5995cc8]the problem was a fuel pump it would have low pressure during driving speed. thanks to lumlumsweetie for trying to solve. rick h[/quote:86f5995cc8]8/29/08 the problem was solved by a 10 yr volvo mechanic on his own time The $ was fair and it runs like a volvo should. throttle position sensor was checked it was fine. a d test was used to fix. thanks for all help rick h

So what did your mechanic say the problem was ? About how much did it cost ?