Engine/Transmission (1998.5 - 2002) air dog install questions

[telliott]

Just got my airdog 150 today. Excited to install, but i have a few questions first.



-Anyone have torque specs for the fitting that goes into the vp44?



-The instructions say to compleatly bypass the factory fuel filter canister. is this a good idea? i have heard some guys are bypassing and some are not. What is best?



-return line from engine: I used to have the system from glacier diesel with the walbro pump. I think its called the gfs-392. Anyway, it had a regulator in the return line from the engine to the tank. Should i remove that so the return is straight through to the tank? or can i leave the regulator in the line.



-I dont have the in-tank fuel pump. Is it still necessary to install the new suction hose in the tank, or can i just use the factory pickup?



Any tips would be appreciated! Thanks!

 

[Midnite]

I bypassed the stock canister and am perfectly happy with it. If you do so, you give up the Water In Fuel sensor, but for me that's no big deal. I routinely drain a little out of the water separator after the truck's been sitting overnight and have yet to see any water.

I don't know on the regulator, but I'd probably pull it.

Mike

 

[Wyomingcowboy]

I decided to keep the factory filter for a few reasons -

1. WIF sensor

2. Fuel heater

3. extra filtration never hurts. There are plenty of us who have gone either way and been happy.



As far as the regulator in the return line, why is that even necessary? I have never heard of the reason behind that.

 

[telliott]

I guess i wasnt even aware these trucks had fuel heaters. What good does that do? I thought hot fuel was bad for the vp.

 

[Bob Cochran]

I decided to keep the factory filter for a few reasons -
1. WIF sensor
2. Fuel heater
3. extra filtration never hurts. There are plenty of us who have gone either way and been happy.

As far as the regulator in the return line, why is that even necessary? I have never heard of the reason behind that.

I did the same as above except #3 I removed the filter from the canister. So for about 2 years this has been working for me. I decided the extra filter was a needless restriction and was satisfied with the AirDog filtration. I have the 100 not 150 but for this discussion I don't think the differences are of any importance.

 

[ALepley]

I guess i wasnt even aware these trucks had fuel heaters. What good does that do? I thought hot fuel was bad for the vp.

Hot fuel bad for the vp?!?!?!? Just to let you know hot fuel is always going into the vp. Once the truck has been started and ran for a good while the fuel temp rises. The only thing that is bad for the vp is fuel that is lubricated like it should be from adding additives.

 

[telliott]

Hot fuel bad for the vp?!?!?!? Just to let you know hot fuel is always going into the vp. Once the truck has been started and ran for a good while the fuel temp rises. The only thing that is bad for the vp is fuel that is lubricated like it should be from adding additives.

I know the fuel warms up on its own when the engine is running from being returned to the tank. thats why i'm wondering why the fuel heater is necessary. It seems to me the fuel is heated on its own with out the help of a heater. Maybe its just necessary on cold mornings at startup?

 

[Wyomingcowboy]

It would definitly be helpful on cold mornings. That being said, I don't know if it is always heating the fuel, or how much it heats it. Maybe the heater shuts off when ambient temps reach a set amount like the grid heaters? I doubt that it gets heatd much, however. Certainly no more than when it is heated by hot summer air or after it cools the VP and is returned to the tank... .....

I'm sure there is some certain info out there. Anyone else want to chime in?

 

[Midnite]

Since I'm one who ditched the stock filter setup, I don't have the fuel heater anymore. I've had rare situations where it was a cold as -35 F. and I didn't miss the fuel heater. In my case, we have winter fuel formulations so the heater wasn't doing anything for me for preventing fuel gelling. I suppose if you live in an area where they don't blend winter forumations and just give you straight #2 and expect you to use your own additives, then it might help.

Mike

 

[telliott]

well we dont ever see anything that cold here, maybe -15 but thats rare. We also have blended fuel in the winter here so if you can get by with out a fuel heater in Alaska, i'm sure i can live with out it here.



I guess i'm still debating this a little. I know that an extra filter never hurts but is it really necessary with the 2 micron filter on the airdog? what about flow restriction? The main reason i upgraded to the airdog was to maintain a constant flow of 15 psi. Is the stock canister/filter going to effect that? The instructions say to ditch the factory setup but im still not convinced one way or the other.

 

[Wyomingcowboy]

I'm not going to get into my problems with Quadzilla here, but I have a fuel pressure gauge from them and it reads 12-15 all the time at the VP. The AirDog is forcing fuel through 2 filters and I still get pretty good psi. I have often thought about ditching the canister as well but at this point it would be more labor... ...

My reason to leave it is like I said - filtration, and possibly to avoid any CEL issues. My reason to ditch it would be to free up some extra room on that side of the motor. The canister does get in the way sometimes.

 

[telliott]

what if i plumb it through the canister but remove the filter as Bob Cochran did? I would then have the advantage of the fuel heater and WIF sensor but would eliminate any resistance the filter may cause. Except for missing out on the last filter, is there any downside to doing it this way?

 

[Midnite]

I can't think of any.

Mike

 

[telliott]

Thanks for the help guys