Guys - I still need some help regarding the TPS on my 05 model. When it the engine is cold, it seems to start just find. You get that first engine burst over of RPMs you normally get. However, once it starts and reaches operating temp, when you try to start, the engine starts very, very slowly, keeps run, and running slowly, and then seems to catch up to speed so to speak. It reminds me of an old John Deere tractor we had 50 years ago where you had to adjust the hand throttle to make it run faster. It just seems like it needs some input from somewhere.

Also, there is still some sense of lag when you are driving and start to accelerate from a stop light. Once moving, things are good to go. Could this be the TPS? Thanks for any input! I hope I have described this symptom so you can make sense of it.

 

Have you looked in the Tech Folder? Hours and hours and hours can be spent there!

Have you checked the FICM voltage?
https://www.ford-trucks.com/forums/8...procedure.html

 

The FICM was just replaced less than two months ago. Of course, I know that it could still fail. It does not appear to have those symptom that were cured with the FICM replacement. I will check the tech folders for some ideas as well.

 

Have you updated your STC fitting and dummy plugs and stand pipes? Sounds like you're heading to a no start when hot condition.

 

Would also be helpful if you had a Scangauge or similar way to monitor some key parameters like the HPO pressure for troubleshooting.

 

Thanks for the input guys. I think I may have an oil leak. It may high pressure o-ring leaking. When it is cold and the oil is thick it works great, but when it hot and the oil is thin it is not working the fuel injectors properly. Will keep you posted.

 

Your description has me intrigued. Your symptoms, in a way, almost mimic a leaking injector. Do you have a way to code scan the truck and check the fuel pressure? You can also do an air test on the HPO system to check for leaks.

 

look at icp and ipr hot idle over 185* eot and post the info.

 

Guys thanks for the great information. I will post some results soon. Keep up the great idea sharing; it is really great.

 

UPDATE - Well it appears that my TPS was not the problem. It would appear that I have a bad cell on one of my batteries coupled with a couple of injectors that seemed to malfunctions intermittently. The battery was less than a year old, so the good thing was that replacement was free. At any rate, she is back on line an running great. Thanks for all your input and suggestions.

 

Interesting. How did you come to that conclusion? In my little brain, that makes no sense. But I love filling my head with more stuff. Not questioning the repair, just curious how you figured it was the battery.

 

I forgot to add that I was also having an issue with a HP oil sensor. It was showing 200 psi without the engine running, then it would drop to zero. I replaced it as well and of course that stopped the starting problem. The injectors were identified as part of the analysis before the sensor actually acted up. So I hope this helps to clear your brain issue as this will help to clarify.

 

That makes more sense... The ICP sensor showing 200 PSI would definitely cause your lack of throttle response.

Get you some gauges in that truck. You'll be happy you did...

 

I was wondering if anyone knows where the TPS is located in a 2008 Ford F-350 Super Duty 6.4L? I'm new to this - sorry if I posted in the wrong spot

 

I would guess that it is down by the pedal but that is just a guess.

Try posting here 6.4L Power Stroke Diesel - Ford Truck Enthusiasts Forums

Oh, and welcome to the Forums, lots of great info here!