mvr

the problem was the car would start run for about 5 seconds sputtering and caughing until it died. it would throw that code, i would clear it with my xcal2 and it would start right up fine. couple days later it would do the same thing. this happened for about two weeks until finally the other day it did it and would not start again. it just cranks and cranks but doesnt fire up. the code is p0190 fuel rail pressure sensor malfunction, a pretty common problem on our cars, but mostly boosted cars especially. i replaced the frps and it still didnt fix it. i am trying to figure out a way to isolate the problem so im not wasting money and time on this issue. it is my only car right now. it could be the fuel pump, which i am lucky i have a svtf pump sitting in my room. i am reading a thread on svtp where someone had the same issue and they said they took the plugs out and let the cylinders air dry because the motor and plugs were flooded. any help would be greatly appreciated. only recent matinence is i replaced the battery about two months ago with a yellow top optima.

MustangLife

This is what I found....

DTC P0190

Possible causes for this fault are:
- VREF Open Circuit
- VREF Sensor is Open

Disconnect FRP sensor connector. Turn ignition switch to ON position. Measure coltage between VREF and SIG RTN terminals at FRP sensor harness connector. If voltage is 4-6 volts ? You need to measure FRP sensor resistance. Between FRP and SIG RTN terminals at FRP sensor. Measure resistance between FRP and VREF terminals at FRP sensor. Since you've replaced the FRP sensor. The resistance should be 30,000 - 40,000 ohms. I'm assuming there are no other trouble codes.

Than check for Intermittent Fault, which would mean the fault is not indicated and can't be located at the time.

Now if voltage from the first step is not 4-6 volts. Check for Open Circuit.

Turn ignition switch to Off position. Disconnect PCM connectors. Inspect connector for loose, damaged or corroded terminals. Repair as needed. Measure resistance of FRP, SIG RTN, and VREF circuits between FRP sensor harness connector terminal and PCM harness connector terminal. If all resistance is 5 ohms or more repair open in affected FRP, SIG RTN or VREF circuit.

The SIG RTN, VREF AND FRP Signal are 3 of the 4 points on the Fuel Rail Pressure Sensor Harness Connector and the PCM harness has the 3. In case you weren't sure what these were. I don't have a diagram. This was something I printed off a while ago. With todays cars alot of trouble codes aren't as easy as replacing a sensor unfortunately. Best of luck to you. Might want to just take it in to the dealer. I don't what your level of mechanical abilities are. But maybe you'll find the problem easy.

Josh

mvr

thanks for that post, if and when i have to look at the electrical system il start with that. after talking to the local mustang guys i am leaning tward the fuel pump craped out and the result of if acting intermittently was the FRPS code. hopefully they will be able to come out tomorrow with some tools and help me diagnose this problem some more.

mvr

it turns out it was the sensor. what i did to start it again was unplug the sensor, put the car on jumper cables and keep clearing the codes and trying to start it. after a few times it caughed like it wanted to start, then fired up the next time.