I hello all and i thank you all ahead of time for any help. 3 weeks ago i bought a 95 ford mustang with a 3.8 and manual trans. It had two codes p0171 and p0174. Not a big deal or so i thought. my issue is when you try to punch it the car falls flat on its nose it will not rev if you floor it. At start up when the car has been sitting for 6ish hours it will rev to 2k then drop to like 300ish and almost stall out, it then jumps back to 2k then drops back to like 700ish and runs fine. i have replaced the egr valve, the dpfe sensor MAF sensor tps sensor crankshaft position sensor and i replaced both bank 1 and bank 2 o2 sensors i checked fuel pressure and its on the high side of spec unhooked the fuel pressure regulator and it reads as it should. i even unhooked the y pipe and tried to rev it because i thought maybe clogged cats. this car is driving me nuts becuase i can't figure out what going on. Oh i sprayed the intake good with brake clean to see if it had a vaccum leak and no dice on that as well. it kinda sux becuase this car is perfect inside and out not a blemish. I'm really hoping for some insight to point me to whats going on. i thank you all ahead of time for any advice

 

I know you checked the pressure but could the fuel filter be clogged so as when you step on it it cant provide the fuel fast?

But with those codes and its behavior it points to a vacuum leak.

Help for your codes ...its for a 4.6l but should be the same.

 

yeah i changed the fuel filter as well

 

any ideas on how to find the vaccum leak other then using break clean and looking?

 

I have recently completed a major overhaul of a 2007 Mustang 4.0L SOHC engine (55000-miles) including new hydraulic lifters. After completing the rebuild and final start-up, I have detected a rattle in the left front timing chain. I was told that it was probably the chain tensioner. Therefore, I replace the tensioner. The condition still exist at about 2500-RPM. I inspected all of the timing chains and guides and found no defects during the rebuild. My question: What corrective action may be exercised in lieu of dismantling of the front timing chain case and left valve cover and installing a new timing chain set and chain guides? Thanks, Robert

 

hi Robert and welcome. I think you meant to start your own thread Robert..you'll get more help and keep white's on topic

 

Spark plugs shorting out?