96meangreengt

Trying to figure out what gpoing on with my car lately

Sypmtoms: when up to operating temp at random times it will miss realy hard and feel like its got no power for like 2 sec then all is well. happens maybe 1-2 times coming home from work(23miles) usually when im barly on the throttle.

also at idle after warmed up at will idle down to 400rpms and spark knock and act like its going to die then it idles back up and its fine. happens at random times.

it started dong it 3 weeks ago and last week my theft light starting go off and its throwing a code 16. car runs and drives really good the rest of the time just has a hicup here and there.

vacuum- at a steady 20
fuel pressure-30psi at idle

list parts replaced in the last 5,000 miles
idle air control valve
mass air flow sensore
evap sensors
o2 sensor
sparkplugs.

does have a sniper tune
pats is turned on

96meangreengt

any ideas

1998Slow 'Stang

I am probably wrong, but it seems the fuel pressure should be higher.

I had similar problems minus the spark knock with mine until I found that the o2 in bank 2 sensor 1 was completely dead.

96meangreengt

I checked in the Haynes manuel and it says it should be between 30-45 so its on the lower side.

I wouldn't think it ould be a 02 sensor since i replace both upstream sensor last summer oem motorcraft sensors.


I just wonder if it as anything to do with the PATS.

96meangreengt

anyone?

trailor

you should be around 40-45psi at idle, 30-35 at WOT. i don't know much about the return style system though. could be your fuel pressure regulator?? fuel pump and filter? fuel injectors??

if you have a sniper tuner, you can disable PATS, so try that if thats your concern, but it honestly shouldnt even start if PATS is active, much less drive.

i had a problem with power loss at highway speeds with my grandpaws 2007 taurus and it ended up being a bad fuel pump. didn't even have 40k miles on it yet. i was quite the unhappy camper on my 650 mile road trip... fortunately, the daytona beach stealership replaced it under warranty, but refused to guarantee the work because I installed the fuel filter myself.. figures.

96meangreengt

I was told not to disable PATS because it cause more problems to do that than not. I know that the book calls for the fuel pressure to be between 30-45psi at idle and mine is right at 30psi and when you rev the engine it goes to around 45psi.

Only sensor that i have not replaced is the TPS sensor

Does anyone know how the check it?

trailor

once again not familiar with return style systems, but the concept is the same. fuel pressure is supposed to drop at WOT, not raise. the book gives that range for the full rpm band, not for idle.

disabling PATS via a tuner does NOTHING negative to your ride. they wouldnt give it as an option if it caused problems... for new edges, their gauge cluster is married to their computer, swapping either will cause PATS to activate, making the car undriveable. disabling it makes you able to drive the car anyway with no ill effects other then your car wont be as well protected.

although you've ignored just about everything else I've told you thus far, I doubt it'd be your TPS. google symptoms of a bad TPS, i'm sure you'll easily see thats not your problem.