Here's a stinkin' stumper of an issue for everyone out there...and hopefully there's a genius Ford Tech (hint, hint Sal) out there that can solve my little dilemma. Yanked my JDM 4 lb. lower pulley on Friday and installed the new interchangeable pulley on Saturday morning. Go to back the truck off of the ramps and it will start but immediately dies. Truck has about 1/8-1/4 of a tank of gas so I figure it's starving for fuel. Roll the truck off the ramps and attempt to start it...starts but immediately dies unless I run the RPM's up and it's missing badly. Figure I need to let the fuel pump run for 30-60 seconds before I try to start it...no go. Check the fuel cut-off switch...nada. Now I'm getting pissed since nothing I did should keep the truck from running. Make an appointment at my local Ford dealer for Monday and arrange to have it towed there courtesy of Ford Roadside. Get to the dealer and they run some diagnostics on it and claim my K&N filter was 'dripping' with oil and all of the extra oil caused the MAF to go bad. I call BS and walk out with my service advisor and check the K&N...not a drop of oil in the bottom of the box and if you run your finger across the K&N it comes off clean. Fine...they call Ford and suddenly it's covered under warranty. Five hours later (after waiting for the MAF to come from another dealer in town) the service advisor pulls my truck around...with the hood not completely latched...hmmm. He then proceeds to show me that, even with the new MAF, if the wires to the MAF are unplugged the truck runs fine. If the wires to the MAF are then plugged in the truck immediately dies. He also proceeds to tell me that with the chip (which Ford and I had both removed to test to see if the problem went away and it didn't), upper and lower pulleys, throttle body, breather cap and cat-back that the numbers that the tech is pulling off my truck are so far outside the realm of 'normal' that they have no idea what it is. So I limp home with the MAF unplugged and decide to check a few other things...cranks sensor wires near the pulley just in case I knocked them loose during the install...unplug them and plug them back in and still the same problem. Remove the wires from my electric fan in the fuse/relay box...no dice. Short of getting a new computer for this thing can anyone think of what may be causing this??? And I was supposed to dyno tomorrow too!

Thanks in advance,

Dan

 

Have you tried removeing your chip just for grins & giggels? I dont have a clue man??

 

I'm no where near a tech ,

but, since you've gone through so much, try putting your old pulley back and see what happens. Are you running the same amount of boost before the change? Have you checked the fuel filter(has it been changed in the past 10-20K miles)?

Does it feel like it's losing compression? Have you check for a bad spark plug? What year is it? Although I have never experienced it with mine, there was talk of the 01-02's over loading their MAF. Might want to talk to Jim if that applys to you. Check all the vaccum lines up top.

Other than that, that's all I can think of. Good luck.

p.s. Try isolating certain things, like Rich said, pull the chip and check it. Or remove your blower belt and check it.

 

I am just an aviation mechanic but it sounds like somehow the timing is off? it's got to be something to do with the pulley change or at least around the area you were working in. did the truck run fine before you started the work? you left it on the ramps all night? right? It's hard to diagnose when you are familiar with symptoms. there is an answer, don't give up

 

I'm not a Ford tech but, I'll say you need to have that chip reburned for the new pulley ! Goodluck.

 

All good pieces of advice but I did the following:

Removed chip and tried to run the truck without the chip just in case and the truck did the same thing.

Checked around the pulley to see if there were any other possible connections that could have been knocked loose (crank position sensor is the only down there and it's connected).

The chip was already burned for the pulley when the pulley was installed.

Truck only has 2200 miles on it and it runs fine when the MAF is unplugged so it can't be anything fuel related and it has a brand new MAF on it as of today so it cannot have anything to do with the alleged 5.00V on the MAF issue.

All vacuum lines on the motor are connected as they should be.

My last resort is to blame the PCM. If the PCM is bad it may be resorting to the default tables that are used in the event the MAF goes bad but I don't know enough about the inner-workings of the PCM to be sure.

 

There has to be a piece of info missing... The changes you describe dont relate to the problems. Changing a pulley wont make it fail to idle.

Is there any chance something else got disturbed when you were swapping pulleys ? Another sensor got unpluged ? Did you disconnect the battery ? Any chance the PCM shorted ?

Just guessing...

Doug

 

GREAT Point Nitro

A Vacuum leak would act just like what he describes....
Run the idle up is runs but not well.... Easy to fix toooo
Doug

 

Also, did the dealer actually check your fuel pumps? The clamp on them?

Daniel

 

Is it throwing any trouble codes>??? Did they put the right MAF back on the truck>??? Disconnect the battery then try running it. Hey worth a shot. -Mat-

 

Your problem sounds exactly like some of the stories I've heard about the Superdutys CPS (crank position sensor) going out. You mentioned that you checked the connection, but it may have just gone bad...???

Roger

 

Fuel line partially clogged, fuel line loose at pump, one pump defective, or partially clogged fuel filter---low fuel pressure?????

No flame , but I find it interesting that you installed(bought) a JDM pulley and yet, you ask for Sal's help(I just checked JDM's board and didn't see a thread from you over there too.). Thing is, he'll(Sal) probably help you if he sees your thread...................

Dan

 

I was also thrown by the fact that this happened after changing a pulley since none of the symptoms coincide with a pulley swap (during which the battery was disconnected just in case). Checked for any other loose wires around the pulley and found none. The MAF is installed correctly with the 'direction of air flow' pointing towards the intake plenum. Battery has been disconnected several times for a minimum of 30 minutes to drain any residual voltage and reset the PCM. There aren't any vacuum lines that have been disconnected as I have already checked all of the vacuum lines (and it still runs if the MAF is unplugged which it wouldn't do if there were a vacuum leak). I have also ruled out any issues with the fuel pumps as I drove the truck 7 miles to get home last night with the MAF unplugged and it ran fine. It is throwing a code (P0174) which indicates it has a lean bank 1 (due to the breather cap). I'm actually leaning more and more towards a bad PCM based on ruling out everything else...darn it, what does Ford get for those things???

And Lightninrod, I actually didn't post on Jim's board because I called him directly last night (at 11 P.M. his time to see if the had any ideas for me). I just figured that the more "eyes" I could get on my problem the better the chance of getting it solved (and no offense to anyone else on this board, but I figure Sal has the largest base of knowledge about our trucks from a troubleshooting standpoint).

Thanks again for the ideas,

Dan

 

Pull the breather cap off and replace with stock cap.

I had the same problems when I added a breather, even though my chip was programmed for it. As soon as I took off the breather, the problems went away.

 

Sounds like THAT's your problem.

If the CPS goes out, it won't run since it has no reference crank postion to reference for spark ignition. The fact that the truck runs with the MAF unplugged (default mode) and then dies when it's plugged in tells me there's a short in the MAF circuitry. The MAF plug might be bad, the PCM MAF circuit might have a short or the PCM is bad. That's where I would start looking.