Low fuel pressure Duramax

[was_butnotnow]

I have a 03 Chevy Duramax and just replaced the fuel filter (getting ready to head for summer travels) and the next day after about 40 miles it went into limp mode with engine light on. Have enough power to drive but when I try to hit the foot feed it almost stalls for lack of diesel fuel. Got it to me local repair guy late on Friday and he took a engine code reading and it said low fuel pressure. Going to take it back to him on Monday.
Now my question why with a NEW filter this would happen?
We have replace these several times in the past without a problem. You learn when pulling a big 5er in the mountains and you go into limp mode to make sure your filter is good and you have a spare.
But now with a new filter it happens.
I bought a WIX filter 33960XE at $59.99 at O'Reilly auto parts so not a low end filter by any means.
Any ideas?

[BobsYourUncle]

I found an interesting article regarding this problem.

See it here.

[larry_barnhart]

Have you pumped the filter when it is not running good to see if the filter is full?

chevman

[NHIrish]

I would think it it is one of the things already mentioned....bleeder screw. oring etc. I would also think you would be wise to stick with the OEM brand filter for your Duramax. The ac delco filter is darn good.

[tdeal823]

What is the mileage of your truck? If your getting up there in mileage your CP3 could be getting tired. This is common in Duramax trucks. GM Duramax trucks are the only diesels that do not use a lift pump. They use the Injection pump (CP3) to deliver injection pressure to the rail and also suck fuel from the tank through the filter and up to the pump sitting at the motor. That is a long way to suck fuel. If you have any minor air leak you will get a loss in vacuum and starve for fuel. With any fuel maintenance you have to be extra extra clean. I can not stress this enough. Here are the steps I would take.
1...The easiest thing to check is a new filter. If you are using factory style filters you need to clean and maybe replace all seals along with it. This includes the water sensor gasket and the bleeder screw.
2...Is you are reasonably mechanically inclined you can rebuild the filter housing. Autozone, KOI, NAPA will all have filter housing rebuild kits for less than $50. It is all the o-rings and seals for the housing. The housings are very susceptible to dirt and debris at the primer plunger. If you are worried about the work involved you can buy a new housing also. If you get a new housing make sure it is for your year truck. GM slightly changed the hose routing somewhere in 2005-08.
3...Get a NICKTANE filter housing adapter and a Donaldson filter.
http://nicktane.com/osc/product_info.php?cPath=22&products_id=63

http://nicktane.com/osc/product_info.php?cPath=22&products_id=51

This will not always fix the problem. But if you have a week CP3 the larger filter will allow the pump to suck through the filter a little better.
4...The best solution is to install a Lift Pump back at the tank with a good water separator and filter built into one. These are expensive but once done are wonderful. AirDog 2 165 or FASS 150 are great options.
http://atptrucks.com/airdogii165-2001-2010-gm-duramax.html

Feel free to PM me with any questions. I will do my best you help.
good luck
Tony

[UsualSuspect]

I would check the O-Ring, check the WIF sensor for cracks, or the nylon bleeder screw could be worn. If those are good, do you know if the fuel filter was ever overtightened? If so, it may have started a small crack in the fuel filter housing. I have replaced a few on buddies Duramax's that either tightened them to much (Hand tighten only)and cracked them, or took it somewhere where someone else overtightened it. They can be had for around $125 online.
BobsYourUncle - My BIL truck was doing exactly what you described. I replaced the fuel filter housing and he has not had an issue since.

[BobsYourUncle]

I have had the exact same issue with my 07 Dmax. Happened the first time pulling a long grade last year, in the summer with my TT hanging off the back. It only does it when I'm towing.

I put a new fuel filter on it and it made no difference, indicating to me the problem is something else.

I posted a thread on this last fall. See it here.

I never did get mine fixed, as I haven't exactly pinpointed the problem, but research I have done points to an issue some of them have with the fuel line itself. I am told there is a rubber line that goes from the bottom up the firewall and it has been known to get weak and collapse, giving the symptoms of low fuel pressure.

Might be worth checking out more on this.

Mine did it again on a highway trip in Alberta a couple months ago when it was cold out.

Let us know what you find!

[redsb3]

Are you sure the WIF plug is tight and the o-ring is in right. Might just be sucking some air. Did you make sure the old o-ring came off with the filter? And then, maybe RAS43 is right, occasionally there are bad filters.

[RAS43]

It could just be a defective filter even though Wix is a good brand. Had it happen years ago on a 6.5 diesel. Try another filter first.