01 7.3 No power when towing?

[ToddOH43]

2001 F350 CCSB.

Recently when towing a LIGHT load (less than 3,000 lbs. on a 25' gooseneck) the truck has NO power. Does fine on flat terrain, but it wont even pull a minor grade without losing speed.

Noticed that the boost was WAY low (5 to 6 psi) even with my foot to the floor (still in top gear) when pulling up a minor hill on the freeway.

Replaced the up pipes and gaskets, and it made a difference, but only pulls the same hill at 7 to 9 psi.

Fuel pressure is running about 70 psi.

Checked the EBPV tube, no clogs.

Truck runs just fine without a load.

Any ideas?

[7.3550Duty]

Check your intercooler boots, may have a ripped boot somewhere causing you to not be able to build boost. Not sure what intake setup your running but if its stock intake box check your air filter

[ToddOH43]

Originally Posted by 7.3550Duty

Check your intercooler boots, may have a ripped boot somewhere causing you to not be able to build boost. Not sure what intake setup your running but if its stock intake box check your air filter

Intercooler boots are fine, and the stock airbox is long gone. The truck had the DIY intake done long before I got it and its got a fresh filter.

Problem happens only when towing - empty it runs great.

[7.3550Duty]

Umm...do you still have your wastegate hooked up? If so, unplug the red line going to it and go for a spin.

[ToddOH43]

Originally Posted by 7.3550Duty

Umm...do you still have your wastegate hooked up? If so, unplug the red line going to it and go for a spin.

Haven't tried that yet. I'll give that a try and see what happens.

Could the waste gate stick without throwing a code?

[7.3550Duty]

Your wastegate wont throw a code, no monitoring to it to tell ya if its stuck open or closed. I would unhook it, unplug your ebpv and see how that works. You could a big diff but you may not, but it dont hurt to try it out.

[ToddOH43]

Originally Posted by 7.3550Duty

Your wastegate wont throw a code, no monitoring to it to tell ya if its stuck open or closed. I would unhook it, unplug your ebpv and see how that works. You could a big diff but you may not, but it dont hurt to try it out.

Guess I'll have to try that.

Although I would think that if there was a problem with the waste gate, you'd see it all the time - not just when towing.

[Turbostang500]

what boost pressure do you see when not towing?

Is it possible that you think it runs good but haven't been in one that is actually running right?

If you don't find anything wrong with what was mentioned maybe you might have something messing up in the throttle pedal. It is only a TPS sensor and doesn't actually connect to the engine. If the sensor for some reason is only reading to a certain point then leveling out, you will only get the amount of fuel the PCM "thinks" you are commanding.

Not saying it is it, just maybe worth a look.

[ToddOH43]

Originally Posted by Turbostang500

what boost pressure do you see when not towing?

Boost pressures are roughly twice as high when not towing compared to when I am towing.

Originally Posted by Turbostang500

Is it possible that you think it runs good but haven't been in one that is actually running right?

Anything is possible, but it seems to run really well when there's no trailer on the back of it. It definitely was not hitting its potential until the up pipes and gaskets were replaced last week.

Originally Posted by Turbostang500

If you don't find anything wrong with what was mentioned maybe you might have something messing up in the throttle pedal. It is only a TPS sensor and doesn't actually connect to the engine. If the sensor for some reason is only reading to a certain point then leveling out, you will only get the amount of fuel the PCM "thinks" you are commanding.

Not saying it is it, just maybe worth a look.

I'm not going to say that anything isn't worth looking at, but I'm not getting any codes towing or not towing.

The truck runs terrible (wont get out of its own way) when there's a trailer hooked to it. Empty, runs just fine.

I'm really at the end of my rope here....

[Turbostang500]

This one doesn't make much sense to me. I am headed to bed (work mids) and if no one has anything before I get back up, I will try and come up with at least a few things to check.

Any smoke (color) when it is running bad?

Also, when running bad, is it running smooth just nutless or is it misfiring and shaking?

*edit* just noticed that this was my 1,000 post!! lol. ok I am going to bed now!