Hello,


My 2002 Vanden Plas, 8 cylinder, has been running rough since a new fuel pump was installed. The mechanic checked the pressure and told me it was 37. However, I have been reading some posts and I am seeing some recommendations calling for a higher fuel pressure. Does anyone know what the correct fuel pressures should be for my car?



Thank you for considering this question.

37 should be fine. I believe 40 is nominal, and gauge error could easily be 10%.

And... it is pressure above manifold pressure. Notice the tube leading to the manifold on the regulator.

It may be a coincidental issue, but have you tried cleaning your MAF sensor (with a MAF only solution)? Check your MAP also, make sure you don't have a dry rotted vacuum line. Also, peek into your throttle body, if you had low fuel pressure prior to your repair, the ability for gunk to build up there is even more possible. Did the repair include a new fuel filter btw?
I would recommend a BG cleaning kit.... BG 2901 Fuel Kit | Part numbers BG 206, BG 208, BG 210 ....I used it on mine in combination with new primary/secondary chains and tensioners and mine is running awesome.