Let’s back up. About 6K ago, I replaced the oil cooler, removed the EGR cooler, changed the up pipe, had the turbo rebuilt, and installed a new air charge cooler, also did the blue spring deal. Got a livewire and some very mild custom tunes. Life seemed pretty good. After about 1K, I was leaving work, truck was cold, and it cranked a lot longer than it usually does, probably 4 to 5 seconds, drove home, no problems. Maybe a few weeks later I was merging onto a highway, going through the gears (6 speed) and the truck missed while accelerating on the highway, again ran great ever since.

Fast forward to 2 weeks ago, go to start the truck in the morning, it cranks long, but starts, about 4 seconds, it usually takes about 2. Hot starts were fine, normal. But all week the cold starts were long….once it starts, I like to say its started with authority, it kinda “revs” slightly, not really revs up, but it one seconds it cranking, the next its running. Anyway, during that week, at few times, it would stumble at time when I’m accelerating, between 2-3K rpms. It won’t do it all the time. I didn’t drive it much last week. Today, I drive it and in the morning its back to starting within 1 to 2 seconds, and its normal. I still have the hesitation on moderate acceleration, today it seemed worse, on the way home I didn’t seem to noticed it. At WOT acceleration, it seems ok. Its starting to bother me!!!!!! What should I look for

 

How often do you change your fuel filters?

It seems inconsistend that the cold and hot starts are good and bad right? And it is not all the time, right???

how many miles on the truck?

 

It has about 8K on new motorcraft fuel filters, top and bottom. Just turned 188K. The hot have always been good, one second or less. Cold was long for a week, now faster, still having trouble with a miss/hessitation on acceleration. Also no codes. Grrrr......

 

So the issue currently is long starts cold for the past week, now they are back to normal with in the last (lets say)~2 days. correct?

The miss/hesitation is still current, and it is consistent?
what about cruising, slow accel, hard accel, wot as of today?


What previous work or adjustments have been done to the truck?

 

If you can: Check FICM voltage, monitor ICP/IPR cold and hot. I'm thinking your IPR valve is trashed up or sticking or both.

 

https://www.ford-trucks.com/forums/1...ng-videos.html

 

Thats pretty much right, starting normal this week so far. The miss is inconsistent, didn't really happen today. It happened mainly at medium to heavy accel, haven't noticed it at WOT. The only work I've done to it is what I stated in my first entry above. Before that major project, I've never had any engine problems, seems odd. My guess is I may have got a very small amount of dirt in the HPOP sump, and may have damaged the IPR valve, but thats just a guess, I have not done any tests.

I have the livelink software that I can use with my livewire, I've only used it once to record my oil temp and coolant temp after I did my repair. I guess I can monitor oil rail pressure verses desired oil rail pressure? I'll have to check to see what other readings I can check. I was also thinking fuel pressure? I don't have a way to check that currently, I know I should have a FP gauge already......
Thanks!

 

I got my oil pressure gauge form harbor freight for $30 and I use that for fuel and a 2nd for the engine oil.