replaced fuel pressure regulator

[steelisreal]

This is my first post on this forum. I am mechanically challenged and do not work on my own vehicle but I would appreciate any feedback on this topic. My car is a '94 E320 wagon (104.992 engine?) with 108,000 miles. I had a warm re-starting problem which was solved by having the dealer replace the fuel pressure regulator. Now, when the car has been in the garage overnight, it starts fine but I have to let it warm up for a few minutes before I am able to back out of the garage. The engine will "stumble", when I try to accelerate,until it has warmed up, but it will continue running. An independant mechanic told me I could bring it in. He would keep it overnight, and put some sort of sensor on it when he starts it in the morning to determine if the fuel mixture is ok. The dealer told me that since everything is computerized there really are no adjustments that can be made to the fuel mixture. He told me to add a can of fuel treatment (recommended Chevron Techron). Any suggestions/comments? Thanks for your help.

[stevebfl]

It is possible that after the previous problem the fuel mixture adaptations were not reset. Logically a car with a bad fuel pressure reg was being adapted leaner (normal problem is a leak which makes it too rich). If the problem is corrected without changing the adaptation the car will continue to subtract fuel until readapted. On your car that can take weeks. It should happen eventually even without help, although it is real easy to set other "Check Engine" problems in the mean time.

I would ask the dealer, although the service writer probably won't like it with you knowing more about it than he, so go gentle with him.

[meldwyer]

hello ,, i would like to ask how to you remove old f,p,reg,,and what tool,s touse i know that tou open gas cap ,and remove cap off fuel rail but i am not sure about how you remove the old fuel,pressure reg, any help will be useful,,, need help,,,,1994 s/420 meldwyer THANK,S,,,,