Towing our new 21 foot travel trailer up Ute Pass, I lost my #2 COP. Limped the rest of the way home on 7, and bought an OBD II to find the all of my problems, (which is how I diagnosed the #2). After replacing that coil, all the plugs, air filter, oil change - all the stuff we could think of, there's still a 'stumble'. I noticed today, that there's what appears to be a slightly crimped spot at the back curve of the driver's side fuel rail. My buddy thinks he might've bent it while working that side. Here's the question - Could that slight constriction in the fuel rail, (I think it's the return side), cause the stumble?

 

Probably not, It would cause more problrms at higher rpm's under high fuel demand.
I would look for a vacuum hose off and the PCV hose elbows for cracks. You may also might try cleaning the MAF.

 

Do what LXMan said - clean the MAF first. They can cause 9 kinds of problems with jsut a slight coat of dirt.

Good luck, Logger

 

ok - checked the PCV hoses and replaced the valve - cleaned the MAF, and while it's made some improvement,the stumble is still there. My buddy - (the one with the hammer), found a fuel-rail on ebay for about $45, so he bought it and we were starting the process of pulling the old one when we noticed a difference between the first two injectors that we saw. One of them still had the pintle 'hat' but one of them didn't. The Chilton's manual says, "Inspect the injector plastic "hat" (covering the injector pintle) and washer for signs of deterioration. Replace as required. If the hat is missing, look for it in the intake manifold." So - out of the eight, two were missing, and weren't anywhere to be found. One hat is cracked, and will probably disintegrate soon. Could this cause the stumble? Called a couple of parts stores - they have the o-ring kits but don't have the cap or the washer. It's Sunday, so Ford's not open. I'll call them on Monday. (Why wouldn't they sell the hats too?)

 

yeah kinda stupid but autoparts dont carry much electric stuff...or specific things to issues...they have just the things that peeps deal with everyday...

 

should've pointed out - once we got the fuel rail loose, ready to try to drag it out, we got it into the light so that we could actually see the extent of the damage. It just ain't that bad! (I'd put a pic of it here, but I'm not allowed to post attachments.) Since it didn't seem worth the extra effort, we're not swapping fuel rails - I've found a couple of posts containing both Napa's and AdvanceAuto's part numbers for the kits that contain o-rings, spacer and pintle cap. Haven't chased 'em down yet. That's next.

 

Found 'em - PartsAmerica.com - Niehoff Ignition Injector Seal Kit - Part Number: 274081 - $2.79 each.

 

nice...now the fun time comes in ...using the kit !

 

The 'stumble' is gone! Installed the seal kits on each injector - put 'em back in - everything seems to be fine. One thing to add - installing the pintle caps requires 'gentle' force. Had great success with a 10mm socket and a vise.