[Jguck25]

I have a 1999.5 F350 SRW and I am having a few problems with it that I cant figure out so I was hoping that someone on here would have an idea of where to look first..

My truck has lost a lot of power and feels like a dog compared to other 7.3's.. I have had a total of 3 7.3 fords and driven over 15 different ones and all of them have had more power than this one.. I am also getting much worse fuel mileage than I used to get. I went from a consistent 18.5 down to 12.5-13 right when i lost all the power. I brought the truck to a local ford dealer and they had it for a day doing diagnostic testing and such and gave it back to me and said that there is nothing wrong with it at all. That is BS because in their initial test drive they called and told me it did seem slow and not very powerful but then after they did all their testing they did they said it didnt throw any codes and there were no codes in the memory. So i had them reflash the computer and still no better. At the end of the day $250 dollars later they say there is nothing wrong with it at all and it runs great. I get in it and its still bad and NO POWER.

I have also realized the there is very little turbo whistle compared to other trucks much much quieter. It is also horrible when it is cold. If its 40 degrees out I have to let it idle for a least 5 minutes before it will move. If i try before that ill be 3/4 throttle and the truck will barely move at all. like 4 feet per second at full throttle..

I have tried to check for turbo leaks and have come up with nothing.. I just really need help with fuel at 415 a gallon..
Sorry for the long post..

THanks for any help

 

[Jguck25]

I should also mention that I had them test all the injectors and they said that all 8 were perfect and running strong.
I also replaced the air filter with an amsoil filter, changed the fuel filter, and it has a banks 4" exhaust from the turbo back. Did an oil change and everything. Is there a way to check out the intercooler or the turbo?

 

[TonkaThunder]

Is the problem better or worse on cold start?

 

[RT]

Do you have a boost gauge on it? Any way to monitor the MAP sensor data? A loss of boost, either real (leaking boot) or perceived (bad MAP sensor) will cause tremendous loss of power and mileage. This would be a great example of a truck that would benefit from having a scanner monitor multiple sensors while driving. If you had AE, or access to AE, you could monitor your MAP sensor, ICP sensor, IPR duty cycle, and EBP sensor. It would also be nice to get a fuel pressure gauge on it while driving - low fuel pressure will kill power as well. I think TonkaThunder is pursuing possible high pressure oil issues with his question, which would be confirmed by the ICP sensor and IPR duty cycle data. That's a real possibility as well.

 

[TonkaThunder]

That and the EBPV.

 

[Jguck25]

other than when i first start the truck, it seems like the power loss is pretty even across the board warm or not.

No I do not have any guages on it and like that idea of monitoriing all of those sensors while driving.. Where would I get something like that? what is "AE"? I had an EBPV go on a past truck and it sounded like a sand pouring noise i guess, and this truck isnt making a noise like that.

I do have a oil leak but could an oil leak make this much of a difference? Could my problem be low compression?.. I did plow all winter with a superchips 1700 setting on off road setting..

Thanks for the quick responses I really appreciate any help I can get

 

[Jguck25]

I think I found one of my problems :thumbsup: I was looking over everything and I noticed that the wastegate wasnt connected at all, the clip must of fallen and rusted off so im guessing it was stuck halfway open and thats why I wasnt getting very much boost at all :clap: It runs much better down the road so that may have been contributing to my loss of power mileage and low boost.

I am still having the problem that when I start the truck i have to let it warm up for about 5 minutes before it will even move.. I have done extensive searching and found that is most commonly the EBPV. I tried unplugging the sensor like i have heard and it didnt seem to help very much. Not sure where to check other than that.. Possibly just take the whole tube off?