You said everybody keeps telling to do this and that , but don't have a clue. How would you take that? We only have the clues you give us.

 

I see where that could be misunderstood. I wasn't talking about the guys on this forum and by no means meant to offend anyone here. In talking with the mechanics there were several interested ears around and each had their own take on what to do. No matter what I said it was "change this or change that" without ruling out anything whatsoever as though I have tons of money to blow.

I'm thoroughly frustrated with this truck and my comments were not detailed enought to explain that. I apologize for wording my comments in such a way to offend you or anyone else. You guys have provided the ONLY help and clues I've had. I'm at my wits end with this thing and you, JBrew, have provided more help than anyone.

 

Like you I've got an ongoing problem w/ a SES light of 171 and 174.It can be VERY frustratating!! I sympothise w/ you completly

That EVAP thing that somone had mentioned think it was jbrew? Is that the thing on the drivers side on the firewall w/ the green and white hose clamps on it? Could that cause 171 and 174 codes?

 

There will be one big party when this is figured out for sure. That's the EVAP cannister you're talking about but I don't know if that would throw the codes.

 

I've had those codes once but I had caused them while tuning which leads me to believe the ECM needs a reflashing. You are looking every where with no luck. The only other part I can think of is the DPMS(?). I think that's what iy is called and clean out the ltubes going to it. Just look on the driver's exhaust for the tubes.

 

bigwheel don't want to steal your post. but i have a 2002 f-150 5.4 had a miss changed plugs miss went away for about a week then came back changed the c.o.p.'s (uneek) went about a week now miss is back? like you don't know where to go next? sounds like alot of people have this problem but you never hear of the fix?
i don't think it can be c.o.p.'s like you said clear the codes and just comes back with different cly. #'s

jbrew is it possible running this way will run the Catalytic Converter to hot and burn it out as well and thats where bigwheel is getting his gas smell?

 

Could the fuel pump be causing this problem? Not enough gas getting to the injectors creating misfire?

 

Monitor the fuel pressure at the schrader fitting on the passenger side fuel rail. That's where I have mine. Key on without starting will read 50psi. While it is running it will be 33psi. Hit the gas pedal and it will jump back up to 40psi them fall back to 33psi when u stop hitting the gas. See if u are getting correct voltage to the pump. Oh and ck to see the vacuum line to the fuel pressure regulator on the driver's side of the fuel rail is not leaking.

 

I will check that Kaboom. In addition I just spoke to my mechanic friend who just got back into town. He said in the last two years he has treated many, many vehichles that have had water in their tank causing this same problem. Apparently with fuel prices being high many stations are buying lower grade products to keep prices down. In doing so they are getting water mixes that are causing problems. When I read down the list of things I had checked or done along with the symptoms he said that is exactly the problem he's been seeing. His suggestion was to go buy Heat Fuel Injection cleaner which is designed to take the moisture out of the system. He uses it a lot and says it works most of the time. If it doesn't then we will have to bleed the system and try to dry everything out. After I check the pressure you mentioned Kaboom I'm going to try Heat and see what happens.

 

Heet is good. I use Amsoil fuel system cleaner myself. Your choice.

 

Crap, I think I know what it is, I'm pretty damn sure. It just hasn't happened to anyone in along time. Is It still missing here and there or constantly, running like shlitz?

 

mine is help please?

 

Pretty much constantly. Not bad on cruise but anytime I put a slight load on it. Real bad up hill; good down hill.

 

 

Where the Wiring Harness comes out of the firewall (Passenger Side), - Coil wires can and have Rubbed, Chaffed, against the AC Accumulator Bottles in the past with these trucks. You just don't hear about that much.

Eventually a wire or two will rubb thru and expose, IF it gets that far before you catch it. What I mean is, if they haven't rubbed thru, the mag field from the accumulator alone can create havoc with your ignition components.

Do this -

First do a visual at the top of that big Aluminum Accumulator. The Harness loops just above (if it hasn't fallen on it) Look for bare wires or harness damage. If the harness is sitting on top, pull it off , fix the bad wires and tie it back away from the AC bottle (Accumulator.)

If it looks okay and the engine misses @ idle: - While it's missing, grab the harness and push it further away from the accumulator. If the the miss changes or idle deflects, you found the problem.

If it doesn't miss @ idle and the harness is close to the accumulator , but looks okay: - - Zip tie or pull it further (tie it back somehow) - away from the accumulator and go for a drive. See if the engine runs any better.


If the harness is two close and causing the problem. Pushing it it away should clear it up that quick. You'll notice it right away, - if it's missing or chopping @ idle.