Hello,

My 1996 P38 4.6HSE has issues starting when the engine is hot. The car starts fine in the morning when the engine is cold, but if i drive around and get the engine up to operating temps and try to start the car after 5 or 10 min i get a rough idle and sometimes the car will just die. The rough idle only lasts for about a minute and then the car will run fine.

The check engine light is also on and my OBDII reader pulls the following codes.

P1177 and P1179

Has anyone experience anything like this before that could give me an idea on how to troubleshoot this problem?

Thanks

 

check fuel pressure and go from there.

 

I checked the fuel pressure a few weeks back and it was at 25 PSI. I replaced the fuel filter and it went up to 30 PSI.

 

P1177:Maximum Negative FMFR Correction Fault
P1179:Maximum Negative AMFR Correction Fault

Its a fuel mixture problem. You need to find out what is causing it. Could be the fuel pump, could be the MAF, may also be the O2 sensors. You need to get a scanner on there that can read what the sensors are doing and if they are in normal their normal ranges.

 

I replaced the fuel pump last week and everything is back to normal. Just thought I would post an update just incase someone else has this problem down the road. Thanks for the help everyone.

 

Thanks for the follow up. It is interesting that your fuel pump was able to produce 25psi even though it was bad... Mine only produces 15 to 20psi but functions normally.