turbo sputter

[JExum]

On my 5. 9 pulling about 15,000lbs the turbo sounds real choppy like its starving for air (afe stage 2) air filter is clean and restiction gauge is ok. This problem occurrs at 25psi boost, egts 1100-1250, about 1700rpms and in overdrive while the Smarty programmer is set on #3. I can turn OD off and get rpms up to 2000 and this solves my problem as long as my boost stays under 25psi. I havn't pulled the air intake tube off the turbo yet. But when I cleaned the filter about 4 months age the turbo shaft didn't have any play in it then. The truck has about 95,000 miles. Could this be to much drive pressure and if so what is the solution? Thanks

 

[SRadke]

What was your elevation where it was doing this?

 

[cerberusiam]

Does your boost gauge bounce at all and how are you reading boost?



From the initial description, the turbo is surging becuase your rpm's are way too low and its into defuel mode.



Then you say at 2000 rpms's it works fine as long as the boost is under 25 psi, does it do what you describe any time the boost goes over 25 psi?



How high will your boost go when you push it hard?



Are you using the stock turbo? A boost fooler?

 

[JExum]

The elevation was in east and south Texas on a trip from Mt. Pleasant to Beeville. My Smarty was set with the wastegate on with a stock turbo. The max I seen with the wastegate turned off is 42PSI. I agree it does seem like the turbo was surging but boost was not jumping around. When I started out on the trip smarty was on #5 but the egts would get up to 1350 so I would reduce throttle finished trip on#3 truck got less MPGs but was more driveable. I should have tried it on stock to see if egts got better and if surging went away. But it might have have a slight surge on #9 with cruise set no load and boost at 10-15 and egts at 800-900. I get the best mpgs set at #9 because I set the cruise and ride at 65mph, 16-17mpgs

 

[cerberusiam]

I would turn the WG off and see what happens. With an open element filter you might just be hearing a sound oscillation at a certain point if the boost is not bouncing.



Was that a 15k load or GCVW?

 

[JExum]

The load was 2 stacks of trailers so the gross was about 20k plus. The turbo was surging it seemed because the truck was shuddering back and forth. Ok time next time I will try it with waste gate off.

 

[Prairie Dog]

Mine did that one time with a TT in tow when the FF was clogged. I've kinda learned through the years that whenever my diesels don't run just rite, the first thing to do is change that filter.

Good luck,
Scotty

 

[JExum]

Thats always a good starting point I agree. I didn't change the fuel filter because I had replaced it about 3 to 4 days earilier but it is a 7 micron instead of a factory 10 micron. Fixing to go outside and pull the air intake tube off and check turbo for play. First day off in while so time to go investigate. Thanks.

 

[CToney]

You still have the stock lift pump? I believe they can support ~450hp. If you have exceeded that you may have the need for a better fuel pump. Since you have your transmission upgraded and can put the power to the ground. It may be the fuel system. A FASS might be needed to keep a adequate fuel supply with better filtration.

 

[TMutziger]

On my 5. 9 pulling about 15,000lbs the turbo sounds real choppy like its starving for air (afe stage 2) air filter is clean and restiction gauge is ok. This problem occurrs at 25psi boost, egts 1100-1250, about 1700rpms and in overdrive while the Smarty programmer is set on #3. I can turn OD off and get rpms up to 2000 and this solves my problem as long as my boost stays under 25psi. I havn't pulled the air intake tube off the turbo yet. But when I cleaned the filter about 4 months age the turbo shaft didn't have any play in it then. The truck has about 95,000 miles. Could this be to much drive pressure and if so what is the solution? Thanks

Mine does the same thing with my banks set on #6. If the engine is lugging up a hill in OD, the turbo will start to surge when the rpms get low enough unless I take it out of overdrive manualy or it kicks down on its own. Really scared me the first time, so now I always turn off the OD before it starts doing it.

 

[AH64ID]

Thats always a good starting point I agree. I didn't change the fuel filter because I had replaced it about 3 to 4 days earilier but it is a 7 micron instead of a factory 10 micron. Fixing to go outside and pull the air intake tube off and check turbo for play. First day off in while so time to go investigate. Thanks.

Factory on your 07 has always been 7um, and you really should be running 5um.

 

[JExum]

Ordered me a AirdogII 165gpm pump from Matt Gilbert. Matt gave me a great price on the pump and extra parts I requested and was very helpful. Should be here any day now got excited yesterday when Buster Brown's truck pulled down the street but he didn't stop.