CumminsLBC

I am looking at a 98.5 reg cab 5 speed right now, and I have a buddy that had a 2000 and he had a FASS on his and liked it alot, but what I was wondering is if the FASS is going to solve most if not all injection pump problems with the 24 valves? I plan on leaving the truck stock for a while, but I plan on bombing it as soon as my budget allows. Also, is there any bad things about the 98 24 valves since they are the first year for them, or are they about the same as the later years in terms of reliability?

Haulin_in_Dixie

I will attempt to answer this the best that I can. To start with the 98 and 99 trucks had somewhat weaker injection pumps as I am given to understand. I am not a pump expert. My 99 pump lasted well over 200,000 miles, but I did keep the fuel pressure up for its life. Shortly before the pump went out I installed a new lift pump and it was defective and went to 0 pressure. How long I don't know but a few miles anyway. I have no idea if that was the cause of the injection pump failure.

All that being said, the FASS system is pretty much a cure all for fuel pressure problems. Will it wear out, of course it will, the question is in how long. I don't know that. It is built much stronger than any lift pump and may be compared to the motor on your heater. They last a long time. Brushes are replacable so the condition of the motor could be checked by pulling the brushes. The filtering system is far superior to the stock system and a range of different filters are available. I am currently running a 5 micron filter.

To sum up, so long as the motor in the FASS remains in good shape, the FASS is a cure all for fuel pressure problems. If that is enough to keep the 98 injection pump working is anyones guess. I will know though, I have a VP44 built in 1997. I have no plans of it going bad, but that is my thoughts. I am by no means an expert.

To the best of my knowledge the rest of the engine is pretty much the same as later models. I was getting good service from my 99 engine doing very heavy work every day. I did not have the slightest hesitation in installing an engine built in 1997 which must have been one of the first 24 valve engines produced.

CumminsLBC

thanks haulin, that really helps out my decision. I have never owned a diesel, but my buddy has had 3 cummins and after driving all of them, i fell in love with cummins. I had originally planned on getting a 12 valve because of there high reliability considering that i am a college student. But my friends last truck was a 2000 5 speed with an edge comp and a fass and I really liked how the truck drove. And considering that I may be getting this truck for a really good price has made me lean towards a 24 valve.

I also had another question about the FASS, i did a search but had no luck answering this question. I have heard of people running the FASS through the stock filter so that they could retain the stock fuel heater for winter time starts, but I have also heard that the FASS has a fuel heating already in it? Which one is correct?

Haulin_in_Dixie

Both are correct to a point. The stock heater is electric and I would guess gives instant heat in real cold weather. The FASS unit has a pair of threaded ports that hook up to heater hose to heat the fuel. I don't have mine hooked up and actually don't have plans of it but I live in the south. If I experience problems due to cold fuel I may hook it up. I drove big trucks most of my life with no heat on the fuel though.

CumminsLBC

So is it possible to hook the fass through the stock filter to retain the electric fuel heater? I was just wondering this because i keep my vehicles outside and I live in a very flat part of Ohio where it tends to get pretty cold in the winter months . Sorry for all the questions I am just trying to get on top of things if I do decide to buy this truck.

graphitecumnz

You can hook the FASS to the stock filter but you will have to supply your own fitting.

F. Flack

If I'm not mistaken, the cold weather issue of jelling up will happen at the first filter -- the one in the FASS. Therefore the stock fuel heater will not help unless you run the fuel line from the tank through the stock filter/heater and then to the FASS pump.

The FASS' heater is not an actual heater. It only consists of ports on the pump housing that allow you to plumb hot water lines from your radiator for the heat. I've never found anyone who has actually done this, but the possibility exists. I would recommend having a shut-off valve so you are not heating up the fuel during the summer.

I have been using Howes additive to prevent jelling (among other benefits). If you watch the weather forecast and use the correct blend (#2 & #1), and use a fuel additive, you shouldn't have any problems in Kansas. It would be a bigger issue for our friends in Canada and Alaska.

Franklin

tenbrooks

how much heat if any is transfered from the pump to the fuel? i wonder if it would be enough since the fuel is continuosly circulated? all that would be needed is to keep the fuel above 50*f correct?

jthorpe

putting this in the proper forum....

F. Flack

tenbrooks, I'm not sure what the actual temp is for jelling to start. I would guess it's closer to freezing. My local station starts blending #2 with #1 on August 15th to allow for temps down to -10, then adds more #1 on December 2nd to allow for temps down to -30. They back off with the #1 on March 16th to come back up to temps at -10, and completely stops adding #1 on May 15th.

With the FASS' bypass, and the IP's bypass, we are getting a lot of warmed fuel dumped back into the tank -- once the engine is running and warmed up. Jelling usually occurs inside the tank while the engine is off, or during extended sub-zero periods. Once the engine is started/running, the jelled fuel is sucked into the filter causing it to become restricted -- or worse, completely plugged up. The trick is to use the proper #1/#2 mixture for the outside temp, use a fuel additive that prevents jelling, or to get the fuel warmed up prior to being sucked through the filter.
FWIW, Franklin

Haulin_in_Dixie

With the normal big truck running down the road, the gelling will stop the truck at 7 to 10 degrees F.

Ram44maR

CumminsLBC,

Please PM if you have any more fueling questions [including FASS questions].

I've been FORCED into becoming a danger to the '98.5 24v fuel system over the past nine months . If it's got something to do with practically ANY '98.5 fueling issue, I've PROBABLY been there.

I've spent the past eight weeks, for example, going from tank to injectors, replacing and/or modifying every link in the fuel system "chain."

As I've received helpful advice on this [and other] FREE forums, I want to "pay it forward" by helping out others who may now be where I've been before.

Have a great one,
Bill

HOHN

To me, the "heater" function of the FASS is a joke. By the time it actually heats the fuel (read: engine's up to temp), the risk of gelling is over.

Gelling will happen with really cold fuel hits a filter. This means when you FIRST start the truck-- like the first 10 minutes. If it doesn't gel after 10 minutes or so, it won't gel at all.

So the FASS only heats fuel when you no longer need it. Honestly, I think this is a laughably stupid design. Why have it there at all?

Moreover, the stock filter/lp is up under the hood, protected from the outside and warmed by underhood heat.

All other aspects of the fass are impressive to me (except the price). Why they would take a great product and turn it into a laughing stock with a WATER-HEATED fuel heater is beyond me.

Keep in mind that the OEM filter is 10 micron. Running a 5 micron or 3 micron filter on the FASS make gelling even more likely.

Justin

RowJ

I have seen charts for the low sulfur #2 Diesel with gel points as high as +18 Degrees F.
RJ

BigBlue

Glad I don't have to worry about those kind of temps here.