When I do a hard acceleration the truck downshifts and takes off with plenty of power like normal. But when I get to about 20 psi I loose all psi and power. A real bummer when I'm trying to pass somebody on the highway. It did this before a long time ago when I was running low on oil. Could oil foaming cause this or just a bad wastegate. I have about 13,000 miles on the current oil. I'm using a bypass system with amsoil 15-40 synthetic. My truck has a superchip, exhaust/intake mods. Any help please?

2000 7.3 PSD 96,000 miles

 

Foaming oil, low oil, dirty fuel filter, bad wastegate controller, and 13000 sounds like a lot but I am not that up to par on the bypass. At any rate, I would change it and see if that helps.

 

I agree with Barry, change your oil first. Clean, full oil is essential to the proper operation of the engines.

 

welcome to FTE
well id say you have boost leak that opens up under load, or you have your truck defuel, cause you running to much boost, do you have any boost fooler? cause we know you running a chip, so under load your map sensor sees more than it was programmed for and defuel the truck , you loosing power, and it falls on its face.

 

Do you have a boost fooler? Sounds like its defueling to me.

 

No I don't have a fooler, but It's never been a problem before. I've been running this same configuration for six years now without a defueling issue. This includes heavy towing.

 

well than, what did you change since you start having problems with the boost?.
did you try to see if you can scan any codes from the truck? this might tell us more about the problem. but it has to be scanner for diesel trucks, and with ford package.
inspect your turbo for any wheel play in or out and phisical damage to compressor wheel, check you intercooler boots for damage and or loose ones.

 

We gotta ask, assuming can get expensive. May be a fuel filter, air filter,weak fuel pump or clogged screen.

I just re-read the OP. Why do you need to down shift to pass? Sometimes I do, but not usually. That might be a restricted exhaust. Pay more attention to the RPM's/load than the boost next time it does it.

 

I haven't done anything different lately. It just started happening. I had noticed I was a couple quarts low on oil and then topped it off prior to the problem. The truck is an automatic, so it downshifts automatically when I put my foot into it at 70 mph. Has anybody herd of this as a result of old oil or foaming?

 

No I have never heard of that.. I still think it sounds like a defueling issue, but I could be wrong.. Thats where I would start, especially if there are no codes of SES light

 

I run an Edge Evo and it won't run over 80 in tow mode. I assume it defuels as it just falls on it a$$ when it hits 80. However I never do 80 when I am actually towing so it's not a problem. And if I want to go faster, I run the #2 setting. It's not a boost issue and it sure sounds like the same thing to me.

 

this oil runs though HPOP to the injectors at 1000 to 3000 psi so good clean oil is very important..yes a ruff running truck can be caused by dirty oil and some oil will foam (read link below) and make her run ruff..the wrong oil,dirty oil,additives and mixing different oils will some times foam..take her for a run then pull the dip stick out..is it full of air bubbles?? that's foaming..also if you was 2 qt's or more low..its very possible you ran the HPOP out of oil when RPM's are way up there..if oil level gets to low these trucks will shut themselves off instead of blowing up......


What about Additives?

 

How high of boost pressure can you normally get ? Do you have your waste gate connected ?

 

I usually get up to about 25 psi under load without any problems. I have never lost boost before. I believe my super chip overrides the defuel issue. Yes my waste gate is connected. Now I have strong boost up to about 20 psi. When I'm hard accelerating it gets to about 20 and them immediately drops to 0 and I loose all power. When I back out of the throttle, boost and power returns in a few seconds. But a few seconds seen like eternity when your trying to pass someone in the oncoming lane.

 

so your truck is defueling. you have to get your codes scanned and see if you have overboost code. you might have bad map sensor , if you have you friend with 99-2004 7.3 swap map sensor and see if it will help you . unless you scan codes we wont know for sure.