Why could my 01 be losing boost?

[DUNE RACER]

This ones got me bugged. Coming home today and I noticed that my boost will not go past 17 lbs. (20 normal) and the truck seems a little sluggish on the top end. When I got home I checked everything I could think of: Turbo clamps, air filter, exhaust leaks etc. .

Nothing sounds or seems different. My lift pump pressure has always seemed a little on the low side to me, but it never goes below 2 lbs. (3200 rpm. , WOT) and the volume is great. When I primed after the last filter change I removed the inards of the schrader valve and put a hose on it to purge the air. It took about 15-20 seconds then fuel started gushing into the bucket, when I put my thumb over the hose it had considerabe pressure on it so the pump moves fuel just fine.
I don't know what else to check, any ideas.


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2001 black dually,4x4, 6 speed H. O. ,loaded up and then some!

[This message has been edited by DUNE RACER (edited 01-15-2001). ]

 

[DUNE RACER]

Jarsong,
did you ever get your truck figured out, did the memory erase help? Its ironic that I posted good results with my truck in your thread, now I'm on the other side of the fence with the same problem #ad


My truck has no "power enhancement" and I don't think a light foot or lack of towing is the problem, my truck sees plenty of loads. If the engine gets stronger the harder its run then I'm gonna have one honkin' Cummins after break-in #ad

I also forgot to add that I have 9000 miles so far.

 

[Bad Brad]

Hey DR,
Don't forget to check all those turbo hoses to make sure they are tight. You will lose boost if one is loose. Take care ...

 

[DBuchheit]

Originally posted by jarsong:
I wonder... Pull your battery cables over night and test it again... . https://www.turbodieselregister.com/ubb//Forum4/HTML/003200.html

Please tell me more about battery disconnect / memory erase. My truck performance and fuel economy has been going steadily down since it was new, 4 months ago. I got 18 MPG with the first tank of fuel, now I'm down to 13. 5, that's a 25% loss.

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2001. 5 Intense Blue 2500 QC, SLT, 5. 9L 24v Cummins, 4x2 Auto, 3. 54/LSD, 155 inch WB, Agate, Trailer Tow Group, Sliding Rear Window, Line-X over the rail, Leer Cab Height Topper.

 

[Chad Sheets]

Wait till it gets warm out. The fuel out now has junk in it to keep it from gelling up and getting all nasty due to winter temps.

About March/April last year all sorts of people were posting how evrything from washing the truck to changing the oil was showing gains in MPG. Once the winter blend fuels go away, you will start seeing gains again.

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Always ready to help!
2000 2500 Red Sport quad cab, 4x4, K&N, DDI's, straight piped, boost, pyro and fuel pressure gages, Hot Power Edge, mean looking set of 33. 5" tires, Snap On diamond tool box, Marine Corps window sticker, Semper Fi!

1972 340 Cuda'. Original tripple Black, 340 car w/air. Good clean car, super stock springs, Weld Prostars, shaker hood, strong 340 with a 727/4000 stahl, 4. 56... . Bombs away!
NRA Life Member. http://www.geocities.com/chadsheets

 

[Alan Reagan]

My mileage is down about 2mpg right now. The winter fuel is the deal. You should notice a change about spring time.

 

[LSMITH]

You need fuel to make boost. Have you checked the fuel filter? Just a thought.

 

[DHatfield]

What do you mean only 2 MPG less my truck is getting 3-4 MPG less, because of the cold weather and winter blended fuel. Man I hope it gets to spring fast.

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2001 2500HD Quad Cab SLT SB 4x4, HO Cummins, 6-speed, 3. 55 gears, LSD, brightwhite/driftwood, 4w ABS, camper and trailer tow packages, HD transfer case, snow plow prep, group, cab lights, Isspro Boost and Pyrometer gauges mounted on A-pillar, 4" JRE exhaust, BD exhaust brake. 27100 miles and counting as of 1/16/01.

1980 CJ-5, Modified for off-road use, bobbed fenders, 350 TBI, NP435 trans, 4. 56 gears, Dana 300, Dana 44 front, Dana 60 reverse-cut rear axle, ARB air lockers front and rear, 15/35/15 Super Swamper TSL on 10X15 steel rims, Cobra CB, Warn 9000I winch, nerf bars, 1/4" steel rock crawler bumper front and rear, jerri can/spare tire rack, custom roll cage.

 

[illflem]

Duneracer,my 12v did the same thing when mice tore the insulation off the hood and filled the airbox with it. Checking the filter minder will tell you.

 

[DUNE RACER]

Thanks for all the ideas,
I have been running the same tank of fuel for about 3 weeks and the boost has been normal on that tank until now. My fuel filter is less than 2000 miles old and my fuel pressure confirms the same numbers as usual. The filter minder shows 'open' on the airbox.
This literaly happened from one day to the next with nothing changing on the truck, no new fuel, maitainance, nothing. Please keep the ideas rollinin, I'm still #ad
about this.

[This message has been edited by DUNE RACER (edited 01-16-2001). ]

 

[illflem]

Ok,if there's no mice or leaks my guess is that the wastegate actuator is hanging up. If you had a 12 valve I'd tell you how to check it,since you have a 24 I'm not going to stick my neck out.
Most fuels are climatized for the area they are sold in,I doubt if Seattle area fuel has any #1,probibly just a little antigel additive,that won't cause a problem.

[This message has been edited by illflem (edited 01-16-2001). ]

 

[arlan]

DUNERACER,
Are you still having the problem? What are your EGT's doing? Are they any higher than normal and how is your seat of the pants performance? Only two thing I can think of, the first is a leak at one of the turbo hoses, it has happened to me numerous times, at first barely noticable and all of a sudden
EGT's go through the roof, you hear a wind sound and zero boost. Along with checking the tightness of the clamps, check and make sure one of the hoses is not beging to slip out from beneath the clamp. The clamps can be tight and you could still have a leak. The other is a simple leak in the boost line going to the gauge although those usually make a lot of noise.
Good Luck
Arlan

 

[DUNE RACER]

Arlan,
Yes the problem is still there. #ad
My EGT's are the same as usual, but seat of the pants feel is low on power. Its fine until about 2500 then it feels like it starts dropping off, it usually pulls hard all the way up.
The first thing I checked was all the turbo plumbing for a leak or a shifted boot somewhere but its all good there. I don't think my gauge is leaking since I could feel a difference before I started watching for max pressure.


Illflem,
I have not checked my wastegate actuator yet. The only other obvious thing I can think of is a problem with the Exhaust brake
even though it works fine and I use it often. I will look into these tonight if I have time.

Thanks for the help- Zach

 

[illflem]

Zach,if it was the E-brake sticking closed your EGTs would soar,I think it would be very evident if it was acting up anyways.

 

[EricBu12]

Hey all,
On the thing of MPG's down from the cold, I did a little mod. I took off the horn that goes from the airbox to the fender, and put some cardboard over the hole. then I put a air dam on the radiator (in front of the AC condensor) and the combo of those brought my mileage back up a bit. I got 18. 2 last night some street and some highway
thought this might help


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2001 QC 2500 4x4 bronze W/two tone Driftwood, 24valve HO 6sp. Westin side bars, fender flares, Spray on bedliner, soon to get shell Painted to match and Bf Goodrich AT Tires