05 F150 5.4 rough idle stalling while driving – ford truck enthusiasts forums electricity wikipedia simple english


My truck has 162000 miles. Spark plugs were replaced at around 110,000 miles. About three months ago my daughter was driving it and it started to violently shake at idle. I replaced both VTC solenoids. Both of the old ones had screens missing. It was still acting like it had a misfire at idle so I replaced the coils. Next day drove it 500 miles with no problems. The next day went and started it and it immediately stalled. Restarted with no issues. Drove forty miles with no issues. Truck sat for a few hours. Started it up and it stalled again. Restarted and drove about 15 miles and slowed to make a left turn and it stalled. I got it running again but it kept stalling. Turned off engine for a few minutes. Started up and was able to start driving. Turned off O/D and shifted down to slow to keep RPMs above 1500 and made it the 50 miles home. The check engine light did come on so I had the codes scanned and it showed O2 sensor lean. Had the codes cleared and drove it 1 miles home and it stalled again. Had a local shop replace the fuel filter, added some HEAT to the tank thinking maybe water in the gas. Didn’t help. Had the shop put in a new fuel pump as there was a whistle coming from the fuel pump area. When I went to pick it up it started and died right away. Restarted it and it ran fine the 1 miles home and stalled again and check engine light came on. Took it back to shop. Codes were for O2 sensor rich, and some other codes. Cleared the codes and drove it about 20 miles ran fine then started to stutter and then stalled at 70 mph. Had to continually restart it as it would stall every couple of miles. Picked up a new MAF sensor and TP sensor. Installed those and cleaned the throttle body. No change would stall almost immediately. Saw a video about clearing the PCM and having it relearn the idle values. No difference. Picked up a new throttle body and installed. Tried clearing the PCM memory again and started it. Idled rough at about 500 rpm. Anything above that it seemed to run fine but when it idled down to anything less than about 600 it would start chugging and stall. Restarted several times with same results. Tried to hold it at 2000 rpms and it held for a while and then just slowed down and stalled while I was holding the accelerator in the same spot. I also checked the FPDM and it was corroded a bit but wasn’t cracked or any visible holes. Am going to check for an intake leak and replace the fuel injectors next. Any thoughts on what I might be missing? Maybe the O2 sensors? EVAP system? CAM phasers? Although I don’t have the ticking noise like other people have described.

You might want to get torque pro for android phone and a blue tooth reader . That will enable you to see real time data and test results . Misfires that don’t have enough counts to set cel will show . Lots of stuff to look at there, fuel pressure etc . .

Plugs should be replaced every 60k . New plugs are sp546 the 515s were high failure maybe you have those . Use a small amount of dielectric grease on boot ends ,keep plugs clean and torque in 25 to 28 foot pounds . Boots should be replaced with plugs .They go bad with heat and oil it only takes a small pin hole . Clean cop contacts real good . Corrosion is a problem .picked up a FPDM and put that on. Started it up and it ran fine. I just let it run for about 10 past normal operating temp. I drove it in town for about 10 minutes then took it out on the highway for about four miles. Didn’t give it the onions, just a nice drive. Ran great. No check engine light. Couple hours later went a mile to the gas station to fill it up. It was at about 1/4 tank. Filled it up and started it, it died immediately and check engine light. Had to keep restarting to get home. Let it sit with the engine off for a few minutes. Started it up it idled fine. Took it out for about a five mile test drive and it ran fine. Buddy is bringing his scanner out now to read the new codes. Will update soon

For example: the truck ran great on Wednesday. It only had a slight shimmy at idle. No engine light and I got 19 mpg bucking a 30 mph wind at 70 mph for 40 miles. The truck has never broken the 15 mpg mark since I have owned it. It even shifted more smoothly than I can remember.

Yesterday I went out to start it and it roared up to 2200 rpm and stayed there. I hit the accelerator quick and the rpms dropped right down to nothing and it stalled. I restarted it and it ramped up to 2200 rpm again. I didn’t do anything this time hoping it would “come out of it.” After about 20 secs the rpms dropped right down to nothing and it stalled with the engine light coming on. I haven’t have the codes read yet because I’m about fed up with it. I’ve put about $1000.00 into it already. I’m going to double check all the rubber gaskets on as many electrical connectors I can get to, especially the FPDM, coils, injectors, throttle body, MAF sensor, etc. etc.

I guess I thought I was asking for advice, not simply complaining. But in the future I will keep my emotions in check as to not offend anyone!! Thanks for the advice!! I won’t complain tomorrow when I go and try to run my truck, maybe it will run great then!!

Yes this engine requires a lot of learning and it eats parts which are not cheap. So yes it can get frustrating . Most of us have whipped our problems . You will find different personalities here ,keep cool and just get the good out of it . Most want to help basically . I’m too old to have any words with anyone . I refuse to do it . I had father time take my ego out back and shoot it .

I would encourage you to get torque pro, Its 5 bucks for your android phone and buy amazon bluetooth reader for about 20 bucks . . You can constantly monitor engine and study where its going wrong . The android doesn’t even need to be in service . You can run it going down the road .

Good you replaced vcts that’s a good move . Yes check and clean electrical connections its cheap and a good thing . There are connectors under neath drivers side that have been giving problems to some guys some have found them full of mud and corrosion . . You can clean crank position sensor plug but its not easy to get to but very important .

Clean all cop connections . New rate to change plugs out of ford is 60k miles , I agree with that .Change the boots on plugs and clean connections use a tiny amount of dielectric grease on boot ends . It is an insulator so keep it off metal parts , a little won’t hurt much .

I’m sure you can get on top of this . My plug on FPDM was intermittent after putting new one in drove me crazy until I found rolled gasket in connector . It was shutting down every few miles . It was only 100 degrees and 97% humidity crawling under her by the side of the road was a bear .

so here is what I found today. I started at the back of the truck. The FPDM gasket was not seated correctly, fixed that. Cleaned and electric grease on all electrical connectors. One gasket on a COP was broken, the power steering pressure sensor gasket was broken. I will need to order new gaskets for those. Replaced the spark plugs, old champions were pretty worn out. Most of the electrodes were barely visible. Luckily none broke off and most came out relatively easy. Took off the fuel rail and cleaned the injectors. Put everything back together started it up and it sounded like it was going to run good. Started putting tools away and it died. Kept restarting it with no difference. So I unplugged all the O2 sensors and it ran even worse. Would idle at about 200 rpm and then stall. I’m going to take the O2 sensors out tonight and pick up some new ones tomorrow and install them. If that doesn’t take care of it, the only other thing I can think of is that the computer is FUBAR. Any ideas? I am not getting a check engine light since I have tried to get in running today