2001 ford 150 4x4, AT, 5.4L, 288K. Ran rough, fuel intake was replaced (leaking). After install, it started but still ran rough. Engine light was on and sometimes blinking. No code scanner available but knew from past experience about the COP's so decided to replace them all.

I put in all new plugs (Motorcraft), all new COP's (ebay), cleaned all the injectors, and all ohm'd out at 14.8 and had a clean spray pattern. used di-electric grease, new fuel filter, the whole nine yards. Totally disconnected the battery to clear the codes (probably a mistake). Went to start the truck and it turns over with an occasional stumble but no start.

Fuel rail has pressure, sprayed starting fluid in throttle body (useless). Took out injectors on right bank to spray starting fluid in there. Turned over and stumbled a lot but still no start. Got code scanner, no codes (understood cause it never fully started). Theft light turns on for a few seconds then goes out, so the PATS system must be fine. Checked all connections 10 times, So I throw my hands in the air! any ideas? thanks

 

Compression test. Try the original cops, the Ebay cheapos have been pretty bad lately. How much pressure in the fuel rail? Use a gauge.

 

Well the truck is running. How and why, I have no idea. I tested and worked on the right (passenger side) bank since then access is easier, cyldrs 1 - 4. The fuel pressure at the rail pulsed up to 40PSI. Post fuel filter it pulsed up to 80 PSI.

Accidentally pulled the PCM/Fuel relay fuse instead of fuel pump fuse during the spark test which obviously caused no spark. Kinda thought the crank position sensor. But, once I caught the fuse mistake I put all the fuses in and zip tied the injectors in the rail to stop the fuel from spraying. Spark test was then good for all old coils and the 4 new ones on that side. They Ohm'd out fine too. I plugged in one fuel injector to see if the injectors are getting signal, yep good spray.

Compression tested 140 to 160. However, during the compression test the engine stumbled (with only 4 cyldrs?) and acted like she wanted to start.

For the heck of it, I slapped it back together (plugs, coils, injectors) and tried to start it. The motor stumbled, I floored the gas and held it, it stumbled more and more the tada! fired up. It took a while for the computer to relearn but runs ok with no codes, so far.

What was the problem and how did it get fixed? no clue. Maybe time will tell.

The only thing I notice now is high idle, the temperature needle was just entering the operation zone section of the gauge and upon start up it hits 2000 rpm, then drops to 1100 rpm and stays.

tomorrow I plan to button up and test drive.

 

High idle is usually a vacuum leak or a sticky IAC.

40 psi on the rail is good, it should jump up 5 psi when you pull the vacuum line off the FPR.

 

Shouldn't have done that if you had removed all 8 plugs and cut the fuel off in proper procedure.

Be a good time to change your oil now that I am sure fuel and starting fluid has gotten into the crank case.

Run some techron through it for good measure

 

Cleaned throttle body, replaced IAC and checked vacuum lines for leaks, none. still has high idle (1000 RPM) even when operating temp. Ideas?
thanks
John

 

Did you complete testing on the FPR? If you pull the vacuum line off it, if you smell fuel, it's blown. Pressure with vac on should not exceed 40, with vac off should not exceed 45.