ok so bout a week or so ago i first noticed a little miss when i was driving down the road doin bout 50-55mph and it seems like it only does it when im doin a steady speed with my tach at 1500rpms, but then it started to not only do it then but now when im sitting at a stop sign or whatever for more than a couple seconds. When my buddy was doin my egr delete he noticed my boot on my intercooler was leaking a little bit he said that could be the problem possibly messing with the ecm. Im just tryin to figure out if this sounds possible or not. Im going to replace the boot either way when i get back from daytona beach but until then i would like to know if this is even possible. i have a 05 f250 with 155000 miles mostly stock except for egr delete sct tuner and a 3 inch lift with 35s.

 

The oily boots is normal and not the cause of your issues. Our crank case vents into the intake. You can see the hose entering the bottom of the intake just behind the air filter. So some oil makes it way into the turbo and through the intercooler and the associate tubing. It's normal. If your boots haven't popped off, just leave it as is.

The miss could be a few things. Is this truck stock? Has the EGR been deleted? If it's still in place take it out and inspect it, probably needs a good cleaning. Another common issue with our trucks is the injectors develop a "stick" on the spool valves, and it will simulate a "miss" when under a load, or first fired up in the morning. Could also be weak or dying batteries, or a dying FICM. Few things to check, but lets start with the basics. What are your maintenance intervals like, and what oil/oil filter are you using?

 

ok first of all yes the egr has been deleted second ive only owned the truck for bout 6 mnths so my only maintance record is i changed the oil and filter a few days ago with rotella 5w-40 and a motorcraft filter, and also added 2 bottles of rev-x. i had the batteries tested bout 2mths ago and they was good but i will do that again just to be sure, i also tested the ficm at that same time but i will check that again aswell.

 

Ok that helps. Any idea what your fuel pressure is? Are you running some sort of tuner?

 

yeah i have a sct tuner from innovative diesel but i dont have any gauges to tell what my fuel pressure is.

 

Have you tried putting it back to stock tuning to see what happens?

 

no i actually was just thinking about trying that last night i just havnt had a chance to do it yet. i will do it when i get off work i will let you know how it turns out.

 

Keep us posted... Much easier to diagnose in stock form.

 

ok so i set it back to stock and it still is doing it idk what my next step should be but yesterday when i was backing out of work it seemed to do it real bad in reverse so im just kinda dumbfounded.

 

This miss, does it sound like a gas V-8 with a plug wire off at idle from the tail pipe, or is it something like a bag of hammers rattling that you can hear from the interior that results in a surge? These are two different sounds with different diagnosis.

When mine sounded like a gas V-8 with a plug wire off (when listening to the exhaust), number 8 injector was sticking open and about to STAY stuck open.

I forgot exactly what the other is, maybe an HPOP TYPE issue. Can't remember exactly. Anyway, because we can't see/hear your rig, details, details, details.