Ford Power Stroke Nation banner

XTREME STREET question

4K views 39 replies 7 participants last post by  Zmann 
#1 ·
Hey guys, I apologize in advance for the long post.

A friend and I were working on our trucks yesterday and I was installing the Sinister charge air pipes and the intake elbow. After we finished it up we took it out for a spin to see if all the boots would hold.

I have been running IDP's Xtreme street for probably 1,000 miles or so and I really like the throttle response and the range that the power curve comes in. I have NEVER held the throttle wide open on this tune, especially for any length of time.

Well, we did yesterday. I rolled into the throttle until about 30 mph and then floored it. the power was there for sure BUT once I got to about 80 mph the truck seemed to surge, almost like the programming was defueling the truck or something, then all of a sudden the power would come back again.

Fuel pressure stayed at 54 psig at WOT, boost was at 32-33 psig, accelerator position was 99-100 %, ICP pressure stayed maxed out during the pull. We did this a few times and monitored different values on my CTS insight. All numbers looked to be correct though I cannot recall them off the top of my head.

In my mind, the only thing that makes sense to me is that I "ran out of injector". is this possible? other than being bulletproofed with a 68mm pmax and the typical 4" exhaust the truck is "stock". no fuel system mods, stock injectors.


any ideas????
 
See less See more
#40 ·
just for another angle

Over the years I have seen several engines with valves sticking in the cylinder head in the 7.3L, 6.0L and the 6.4L. All were low mileage trucks and two were brand new units in our stock lot. I recall one coming off the carrier popping out the intake.

This happens due to rust build up on the valve stem. Believe it not not the valve guides and stems run with very little lubrication. Trucks that sit stored for extended periods are susceptible to rust developing on exhaust valves that are open while the engine is running and the guide gums up, the valve begins to stick and eventually contacts the piston. I don't think I have ever heard of a diesel floating a valve.

In all of the cases I have seen there was only a mark in the piston and none required bottom end repairs. Additional damage has only been limited to broken or bent push rods and rocker arms. I have repaired all of them by using a transmission valve body hone to clean the valve guide and replacing the valve, push rod and rocker on the affected cylinders. All of my repairs have been successful and none have had repeat failures.

Sight unseen I can't comment on your engine specifically but I hope that I explained this well enough for you. Ford did issue a TSB on proper vehicle storage procedures to help reduce this from happening... among other things.
__________________
Keith
Ford Diesel Senior Master Technician
NJ Native
Diesel Technician Society
Diesel Mentor
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top