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Discussion Starter #1
Well on my 2001 K3500 with 75,000 miles I decided to add a fuel (lift)pump and I can say the results were excellent. I had the same problems with my Topkick (now also fixed) with a Cat engine so I got to the store and bought a '98 GM diesel liftpump made by Carter then removed the fuel line from the tank hooked it all up with a relay and a aftermarket filter. And the results were a much smoother idle and power where sometimes I would step on the throttle and it would hesitate or just be dog tired. I can also say I found the quick connections on the hoses to be quite loose so if you are having problems you should at least consider changing the supply hoses at the tank and engine if you have an older truck, you can get the release tools from KD tools and you can get at the top of the fuel tank by just bending over the aluminum shroud and reaching in. A new hose would give you new o-rings and seals and would help a host of problems I see on this site that are dogging owners with stalling and power issues. Like I said on my Topkick I spent about 3500+ dollars - twice changed the injectors 3 times tuned up replaced most of the fuel lines and with not a visible leak , always stalled after startup (hot or cold) and sometimes almost no power I was baffled - I added the 125 dollar fuel pump and not a problem since and that was 2 years and 15,000 miles ago.
 

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Good on ya Diggin. Have been thinkin of doing that myself but wasn't sure if it would be a waste of time or not. This will be a mod I see in the not so distant future. Thanks
 

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Good to hear your experiences diggin. I'd like to share my thoughts about secondary fuel filters and lift pumps. In Dec. '06 I installed a TFI 56 gal replacement tank (on sig truck) and at the same time added a Nictane filter between the tank and the fuel cooler. Easy install and no fuel lines cut. On the inlet to the Nictane filter head I also mounted a single KD lift pump.

Now for the results. Prior to the tank/filter install I changed the OEM fuel filter. On the KD fuel pressure/vacuum gage the reading went from 4.5" vac to about 1.5"vac. After the tank/filter/pump install, with the pump deactivated, the fuel press now measured 4.5" vac, about the same as the "used" fuel filter. Now I haven't yet activated the fuel pump (too busy (lazy), too cold, too wet, etc.) I expect to see the fuel pressure reading go to a 3-5 psi from the 4.5" vac.

For those who have added extra fuel filtration but not any type of lift pump, do you experience any idling issues? Any power loss issues? I know that my truck seems to be on Valium when the fuel filter got used, and always seemed to have more pep with a clean filter. It almost seems that the truck sees a secondary fuel filter the same as a used (plugged) filter.

Anyway, I plan on completing the electrical install on the lift pump before the end of the month and then do a 1500 mile trip to Idaho, so I will report my impressions after that all happens.

Mike

PS I should update my sig, I have had the Edge w/attitude installed for a year now, usually only run 1 - 3 depending on if I'm towing or not.
 

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Discussion Starter #4
Yes I want to add a fuel gauge also but I know the Carter pump (available at most parts stores) can't produce more than 5psi so it's safe for over pressure and is by far better than vacumm . I just can't believe they never installed liftpumps in the trucks , a frame mounted pump is so simple and I am sure it would have saved them millions in warranty claims against injectors etc. There has been a couple times now when I was at the dealer getting parts and I overheard a service tech sending away a Duramax owner saying they didn't know what his problem was cause most of the time the fuel starvation doesn't produce a code. Oh another thing I forgot to mention was that you will know if the screen in your tank is iced up or your fuel is gelling by when the engine is running the primer will suck itself down !! This is for those without pumps. Good luck.
 

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What store did you go to to get the pump.
 

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If you are just looking to make positive PSI most of the time, the AC delco pump from the 6.5 will work, but it's not much of a pump in terms of volume or flow potential. The internal passages are quite small. I have made some special fittings for this pump to install between the fuel cooler and tank and still have a few kits:





My preference here is the Kennedy single (or better yet twin) pump but the above is better than nothing.
 

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Discussion Starter #7
Hi Kennedy , that's a real nice setup. I used two ends that were straight and then you could mount the pump in the frame right by the fuel tank just under the fuel lines. Yes I know the pump is no real big volume pumper but it has everything the truck needs and probably more, all I know is it works great and they are in stock just about every parts store including yours. It is important that they know that if they don't buy it with pre-made fittings like yours that they must buy adaptors that they can loctite into the 3/8 fittings.
 

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Hi again Kennedy , I was looking at site again and people should also consider the wiring harness like yours- real nice. I wanted to ask you if you think it's needed to pre-filter these types of fuel pumps , I know there is a screen in the tank but you seem to know the pumps internal makeup. Thanks.
 
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