ok heres the problem. for the past 6 months my truck has been running bad. the SES light came on and through a bank 1 lean and bank 2 lean code. I can drive the truck with no problems as long as I don't excelerate hard enough to get into boost. if i excelerate hard enough to get my boost to 1+ PSI the RPM's jump and hold, at idle, around 1400. It used to hold higher (around 1900) until we lowered the TPS and idle. But sometimes when i go WOT it wont hold at all. AAAHHHHHHHH!!!! I have tried everything I know to do:

checked and switched out the IAC
checked MAF (Pro-M)
put stock MAF back on
put the entire stock intake back on
Sprayed carb cleaner on all my vacuum lines, no engine rev
pulled chip
checked 02 sensors and changed them
someone suggested the fuel filter, changed that
had ford reflash the comp.
I checked every vacuum line
checked the EGR and changed gasket
checked throttle body to see if it was sticking, it was clean
checked TPS
took the plenum and blower off and checked for a pinched gasket
checked all the hoses the connect into the rubber boot of the intake

im sure ive done more, but i cant figure it out. i have a couple of buddies that work for ford, and they spent days looking for the problem and couldnt find anything. if you have any idea, dumb or not, please give it to me. im on my last straw.

thanks for your help
kurt

 

Kurt, have you checked your tune if you are running one?

 

yes i do have a chip. i bought the chip about 3 years ago, Blue Superchip, and had never had a problem until about 6 months ago. i pulled the chip and the problem was still there. i plan to get a predator as soon as i figure out what the problem is.

 

Are you getting enough fuel pressure? One of the two lines from the fuel pump assembly had slipped of on mine and my truck acted alot like yours. The fuel pressure was only 25 lbs or so. They removed all of the crimps and put hose clamps on all hoses. No problems since then. I think normal fuel pressure is around 50 lbs. Hope you find it.

Cesar

 

Kurt

There seems to be a rash of in-tank fuel line clamping problems latley,
I would DEF look into that one

Also may want to consider a bad Injector Driver in the Computer

And I've also heard of MANY fuel Pump RELAYS going back recently too

 

Check fuel pressure ?
Check boost actuator ?

 

Like rob mentioned if it is a 99 def check the fuel pump line in the trank. Also it could be the PCM not operating correctly

 

Pull the negative terminal off the battery with the head lights on for about 10 minutes to reset the computer. Good Luck !! Maybe your PCM took a dump?

 

called my buddy and he said that he checked the short term and long term fuel trims, fuel pressure, baro, egr flow, and data logged before the problem and after the problem.

i did reset the computer by pulling the neg. battery cable

by checking the fuel pressure, doesnt that take out any problem related to fuel

 

injector driver? how do i check and see if that is working properly? what should the parameters say when i check it?

also could it be my single blade throttle body? this problem didnt start until i took the plenum and T/B off for cleaning. maybe i jared something loose when i either set it on the ground or on the work bench. i checked to make sure it wasnt sticking but thats all. is it easy to bend the plate inside? could the plate inside be bent or just not sealing properly and allowing air to flow by causing the high rev? could i have possible done something to the linkage on the side of the T/B? do T/B go bad over time? just trying to get all the possiblities of the T/B out of the way.

thanks
kurt

 

Kurt i know this may sound silly and its such an easy mistake for anyone, but did you reuse your old gaskets? did you put them back on? where they ripped or torn? did you put the upper intake gasket back on the propper way? you might have a vaccuum leake around those areas you can check that with the carb. cleaner too.. just a thought to try and help ya out..
Richie

 

what is the actual code # it is throwing?

 

Great spot to start, amof I have software on my puter to bring it right up
See

Mine went from being too lean with the 50's, to too rich with the 60's. I guess
I rather foul a plug than melt it, hehehehe

Unfortunately the Drivers are built into the Computer, if they go bad, AND THEY DO, you have to either toss the puter and get another, or I belive you can use an aftermarket outside Driver Box, Sals old truck uses one I believe ?

 

Hostile, I did reuse my gaskets when i took the plenum off. Before i put it back on i checked the gasket to see if there was anything wrong with it. trust me, we have drenched my engine with carb cleaner on every possible part and in every possible place you could name.

Late, i dont know the codes ill find out later. everytime i get my them checked at ford it says too lean bank 1, too lean bank 2.

im going to try and replace my T/B with a buddy of mines stocker and see if that works. Im keeping my fingers crossed.

kurt

 

Check your throttle cable. I had the opposite problem, idle off. On my set up the throttle cable was way too loose. After adjusting the bracket angle, with vicegrips, got it to around 700 rpm. After I had it tuned it sits right at 800.

If it is only happening when you go into boost (&WOT), is the throttle cable itself hanging up somewhere.

If it's not mechanical then it's electronic. If your throttle cable is taught when this is happening then the puter is not allowing it to idle down.