A few months ago I purchased a stock 1997 F350 PSD with 150,000 miles owner sts tranny rebuilt at 110,000. I put an aftermarket airbox and filter, 4 inch exhaust turbo back and superchips micro tuner set on middle program towing <8000 lbs. Truck seems to run fine around town and on highway until I encounter a long hill. My speed with drop down to 50 - 55 mph with rpms 2500-2600. It's as if it's has hit the wall or is governed. As the incline decreased power will come back and accelerate again. It runs smooth during the climb just has no power and just about everyone on the road passes me at will. There does not appear to be any leaks around the turbo or the tubing leading to the intakes. I have a new ford lift pump, new fuel filter, new cps. No codes show on the tuner. To me the truck seems to run fine until this one situation is encountered there is not any rough running, sputtering or smoking just nothing left power wise. I don't have gauges to see what the boost is at. Where do I go from here? Also this is both in or out of overdrive and the transmition does not have any noticable slipping etc. Please Help!

 

does the power lose happen right after your added the scmt? try returning the truck to stock, and go for a test drive. keep us posted!!

 

I don't know. I only noticed the lack of power when traveling out of town into the mountains. I just removed to program and have not been in a simular situation again.

 

At the risk of sounding like a smartbutt, the answer to your question is a little thing called gravity. You are trying to move a 7000+ lbs truck up a hill. That is a lot of weight. If you down shift (or in an auto just floor it) it should come to life, just will turn a lot of RPM's. If you do that and it still won't go then maybe you have a problem, but I doubt it. My truck is the same way. Just something you deal with.

 

The only time I have noticed any downshifting on hills is when I am towing my 9K trailer. Even towing it doesn't smoke or grumble, it just digs in and goes.

Frank

 

Markh, I know that you said the pump has been replaced, but this behaviour sounds like a failing fuel pump or loss of/low fuel pressure. Suggest getting a fuel pressue guage, installing it, and go hit that hill.

 

yea something's not right - with your rpms around 2500 - you should have all kinds of power - especially with the SCMT!! I'd have to agree with Kwik that it sounds like you are just not getting the fuel to the fires...

 

Well gravity is not the answer I was looking for. It should dig in and go as was stated by someone else. The throttle is to the floor at 50 - 55mph and only 2500 - 2600 rpm and the tranny has kicked down overdrive off. It does seem like a fuel supply problem but when there is a slight brake in grade power returns and the pulling begins. I it possible some sensor is cutting the supply to prevent over boosting? I this a symptom of a bad high pressure pump or throttle control switch? Everyone around here with like vehicles tell me something is wrong they can pull trailers up the same hills and have to back off because of high egts not any lack of power. I need to check my Fuel pressure now thanks! Keep the ideas coming. Thanks!

 

that came to mind when i read you problem, when you added the tuner you increased the boost the turbo can make, and going up hill with you foot all the way in it you could be "overboosting". if the MAP sensor sees more than about 24psi of boost the PCM will defuel the engine (and set the SES light) to try to control it. you can get a "boost release valve" that installs in the MAP sensor line to take care of that problem. when the engine defuels you should also be seeing a "service engine soon" or "check engine" light (what ever you truck has).

 

No lights showing at all. I have not had a chance to even look at anything yet. But would the evbp be closing causing this? I have read in other threads about the check engine light or other warning lights coming on when an overboost is detected and decreasing the fueling but no warning lights come on. No codes are found with programer. I was hoping for a simple fix before I put more money in the truck (ie. gauges) just hoping there was something I was missing that was the cause. Still need to check fuel pressure delivery though. Thanks!

 

markh
Do you happen to have a boost gauge installed?
If you do what was the boost?

 

return the truck to stock and go for a test drive

 

Mark, I knew it wasn't what you were looking for, but I had to put it out there as there are some people that might just think you should have just as much power as ever even climbing a hill.

I hope you figure it out as I am sure it is frustrating.

Again, I didn't mean to insult you by what I wrote, but with some people you have to make sure the basics are covered before jumping in any deeper.

 

For a quick fix, try checking the fuel filter and the screen in the separator bowl. Make sure everything is clean there before digging too deep. I've got a 95 that flies up the mountains in Colorado and I have to watch to keep my speed down at 11,000 ft. on some pretty steep grades. It's worth a look.

 

Thank you for all the input. I did clean the screen and fuel pressure was around 50 at idle. I increased the regulator spring pressure to see if that made a difference and it did. The truck would hardly run,and would die when coming to a stop. I returned the regulator to the stock position and not much change it still would not run smoothly. It was towed to a mechanic and diagnosed with an injector problem. After 4 new injectors and a handsome bill it runs like a new truck. It appears there has always been a problem with the injectors. The truck runs great far better than I have ever experience it being. Thats with the stock program. I am afraid to install the programer now it runs so much better.