Working with a new fulel filter, I have a fuel pressure test gauge hooked up between my fuel pump and fuel filter.
Ive been watching the gauge when I start the car and notice about once out of 5 starts, the pressure drops down to around 20 then back up to 28-30psi.
usually it goes straight to 50 or so right at startup and then to 30psi at idle and stays at 30 for idleing.
Should the pressure dip to 20 at startup? My pump sticker says it was made in 2-06. Im not sure if this pump falls under the 06-9-9 TSB or not. it does have a 7R33 instead of the newer 7R3Z part # prefix.
Reason for all this is from time to time the car would stumble right after startup for about 2 seconds then correct itself. It would only do this from time to time and only when warmed up and after being shut down about 10 mins after a drive.
Over the corse of a couple years the stumble caused a code. the codes were the same for each incident. the codes were P0171 and P0174 - lean condition at the right and left banks. I also replaced the MAF sensor with no changes to the stumbling.
Thanks, John
Ive been watching the gauge when I start the car and notice about once out of 5 starts, the pressure drops down to around 20 then back up to 28-30psi.
usually it goes straight to 50 or so right at startup and then to 30psi at idle and stays at 30 for idleing.
Should the pressure dip to 20 at startup? My pump sticker says it was made in 2-06. Im not sure if this pump falls under the 06-9-9 TSB or not. it does have a 7R33 instead of the newer 7R3Z part # prefix.
Reason for all this is from time to time the car would stumble right after startup for about 2 seconds then correct itself. It would only do this from time to time and only when warmed up and after being shut down about 10 mins after a drive.
Over the corse of a couple years the stumble caused a code. the codes were the same for each incident. the codes were P0171 and P0174 - lean condition at the right and left banks. I also replaced the MAF sensor with no changes to the stumbling.
Thanks, John