Okay, a few months ago, I had an issue with my Ex. It would have a weak hesitant start and idle real low, I mean like 3-400 rpm low. Typically I am seeing about 700 rpm at idle. Anyway, when I would start it and it would have the low rpm, I would put it into Drive and I had absolutely no throttle repsonse whatsoever, it went strait to the floor. I turned the truck off and turned it back on, and still got nothing and after a few times the truck just would turn over but no fire. Finally after letting it sit, I got it running.

So, dropped it off to the dealership, they could find no codes. I had them replace the fuel level sensor under warranty becasue it was all screwed up. Well since than no problem.... Till yesterday. It started happeneing again, I got the truck to start but it felt like it was going to fall right on its ***. And again, no throttle response. I was starting to get really upset when it left me in the grocery store parking lot idleing at 500 rpm. So in my fit of rage. I started stomping on the throttle in an attempt to get something going, and surprisingly it had slowly crept up and would boost up and throttle response was back. So, I get going, and get home and get ready for work and then leave, and the truck started acting up again when trying to start up. It seems like once the truck gets going it doesnt have a hiccup in the world. And gets me to where I need to go with no problems, but starting my rig up, is just killing it and causing it to fall on its face. Anyway, I get no Check Engine Light, I dont have any tuner hooked up to it. I wanna take it back to the delaership, but when I did that last time, It pulled no codes. Any thoughts? Please help, thanks.

 

Take it to a different dealership.

The symptoms you describe are commonly caused by high pressure oil system problems, injector problems, and software issues. You need a dealership that will spend some time with it to find the root cause, not just check for codes. The fact that the truck does or does not have codes means very little.


Jay

 

Yeah, I was thinking the same thing. Here is a lil more info. I parked the truck tonight at around 6:45 and came back out at 10:30 to start it up, and not a single issue, it fired right up and didnt not even think about stalling. I took it off campus for a lil ride and to go up to McDonalds and pulled back in to my usual spot turned it off and fired it back, and it idled real low again, and had no pedal repsonse. Did that for about 5 minutes and I was stomping on the accelerator pedal this whole time and it started to slowly climb the RPM band to allow full throttle response. It seems like when the truck is cold it starts up fine but when it is warmed up it has this stall. Again, just a lil more information added.

 

Early signs of very small "high pressure oil" system leaks perhaps.

 

I was thinking the same exact thing, also.

 

Mark, What do you think of an EGR valve sticking open at shutdown?

 

It sure wouldn't hurt to pull it and see what it looks like.

 

As in the possibility of it sticking while it is warm, and when I dont start it till after a few hours it has unstuck itself? Good possibility. Would that send a code?

 

My concern with the EGR theory is that stuck valves usually show more symptoms cold than hot, but it is certainly something to look into. EGR codes are often present without symptoms, so even if you had codes they may not be related to your problem.

I would probably be taking a close look at the high pressure oil system PIDs and looking for harness issues.

Jay

 

I believe I have a EGR valve that sticks both hot and cold....

Almost the same symptoms...

Park, turn off motor, go have a coffee, come back, and it works fine.

 

Yeah, but for me I would have to drink about 6 cups of coffee. It seems like when it is nice and warm it just wants to give up. But when it has been sitting for a few hours, not a hitch.

 

Alot of of names I recognize LOL. Bismic and Cj, isnt another option get a sct and have it turned off and eliminate it period.

 

If it starts normal when cold and hard start/no start/long cranking before start when hot, then my bet would be on high pressure oil system.
How many miles on it? Have you had any work done with your injectors?

 

It has 68K miles on the motor, and never had any work done on the injectors. While its under warranty I didnt even want to put a tuner on it, I was going to wait, but it looks like i might be purchasing a livewire tommorow. The only other problem this thing has had has been a failed EGR about 25K miles ago.

 

The reason why I asked about injector work was because I had dealer working on my truck and damaged the threads holding high pressure rail, so it came loose and broke #8 injector (right after my warranty was up). In either case, sounds like you still have the 5years 100k warranty on it, so just take it to the dealer and have them figure it out, but I still betting on high oil pressure problem. (If you have money, and thinking on keeping the truck for a while, get extended warranty on it, I thing with 6.0 it will pay for it self soon, at least it would if I had it on my 03). Good luck.