Zedx148

Well my fass has been in for about a month now. The truck runs smoother and seems like it may have a little more power. However, last week it started to crank a few more times than it used to when it was warm. Finaly, I went out to start it after sitting for 1/2 to 1 hour and it wouldn't start. After it cooled completly it started right up.
I just went outside and duplicated the previous events and it wouldn't start again. After reading the fass troubleshoot I pulled the fuse from the fass and it started up like a champ. I've already had these similar problems which led to an injector pump replacement about 15 months ago.
In the troubleshoot it mentions (Honywell Hobbs part # 78143) which keeps the fass off until 3-4 lbs of oil pressure build. Does anyone know more about this part or my problem? Also does the spring help? What about flashing, I don't know much about it but could this help?
I added a quote from the troubleshoot for clarity.

I also don't want to admit the fact that I may need a new injector pump, but what is this hpvp I hear about? How much extra power, cost?


Lower the fuel pressure from the FASS system. Early FASS Fuel System units for the 24 Valve Dodge (Serial # 1378) came out with the PS-1001 spring, usually around 10 – 11psi. Later units (Serial # 1379) came out with the PS-1002 spring, usually around 16psi. The cost for the spring is only $7.50.
Most customers prefer the higher pressure from the PS-1002 spring. If this is the case we recommend an oil pressure switch (Honeywell Hobbs part# 78143) on the ground side. This is done by placing the oil pressure switch in the oil gallery (on top of the oil filter). Then disconnect the ground from the ECM and (if it has it) the ground to the battery from the FASS wires. The ground wire is then connected to the oil pressure switch. This will delay the FASS pump until the engine has 3 – 4 pounds of oil pressure.

Diesel-Dan

1. The Pressure switch works well. All you need is the Hobbs switch and plumb it into the extra oil port on your filter head. Cut the Green wire, going into the Relay, back far enough to splice on an extra length of wire. Take that wire you spliced to the relay plug and attach it to the Hobbs switch.

2. You can also so the same with the "relay trigger Hot wire". Just cut the red wire (In the FASS harness) between the Stock engine harness and FASS relay. Splice an extra length of wire on the section going into the relay. Then tap that wire to a fuse that is hot only in the "Run" Position (EX: Power window fuse)

3. You can also get your ECM reflashed as well with the latest from DC. The can be done one of 2 ways: Go to the dealer and have them do it, or find a buddy with a Smarty (OR just get one! ) and try it out. Once you flash your truck (EVEN when going back to stock) it will update the ECM with the latest and greatest.

4. Flash your truck with a Smarty Tuner. Once you go back to stock, it will load all the updates from DC with the stock flash. This has also been shown to help with the hard starts.

5. Hate to say this one at all......but VP might be giving you fits. BUT working one these things has showed me that VP's only get worse when you start seeing symptoms. SO its worth waiting it out before sinking TONS of cash into a new one.

Hope this helps!

Zedx148

Yes this helps, its nice to know of someone who has done it. Thanks again Dan. Where can I get that switch? The fass troubleshoot also mentioned "disconnect the ground from the ECM". Is that step unnecesary when doing it as you described in your #1 example?

I'm not a'feard of doing it and I have the basic concept of no pressure at start up, I just don't want to fry something important.

Diesel-Dan

The way i look at it, as long as you keep the ground from the batt going stright to the FASS you will be fine. The ECM ground wire and the BATT (NEG) wire "T" into each other. Along with the ground to the relay. SO you are just taking the relay ground off that line and moving it to the Hobbs switch.

Hobbs switch: PN-78143

Look on eBay for the switch...we do not stock this any more due to not being very popular...but its a very common switch.

BARTMAN

What????
I have had NO trouble at all with my FASS and will NOT screw with it! I initially stretched my spring until they came out with the new spring kit, and then bought it. I run a constant 15-16psi in the winter, and 14-15 psi in the summer with no problems. The truck, now with 54,000 miles starts at first hit, and runs like a jewel (well...this week at least).
Are you guaged? Can you verify the FASS is the problem with starting before messing with it?

Diesel-Dan

Personaly...i agree...i never once had a hard start with my FASS at all! AND MY VP was done the same time my FASS was back in 2004. This hard start thing is like a Texas Tornado....it will jump around and hit at random. These hard starts are some times tough to pin down....But this fix seems to help the majority.

Zedx148

I replaced my lp with the fass because it was going out. I am gauged and I saw 3lbs on several occasions. I would start to limp home and then it would jump back up to 14 lbs. I had a leaky isolator in my setup and was hoping that it was the gauge isolator (and not the lp) since the lp and vp had been replaced about 15 months ago. Hence the gauges.

I am having similar symptoms from when I replaced the vp originally. I think the low pressure may have toasted it?!!? If you refer to the fass troubleshoot that Diesel Dan has in the start of this thread, clear at the bottom it says to pull the fuse if this happens. Once I pulled the fuse it started right away without hesitation. This was after cranking for about ten seconds.

Prior to that the the truck had been running better than ever. I am open to other ideas but it looks like I will be looking for the oil pressure switch. I understand that my vp is probobly on its way out (and the problem is not the fass) but the vp still runs smooth and does not smoke. Can I squeeze some more life out of my vp?

I'm getting kind of frusterated, what good is a truck with a motor that is supposed to last forever if I have to keep throwing big bucks at the parts that keep it runnin'!!!??? I'd rather be buying Smartys and exaust!!!

Diesel-Dan

VP-44's are weird birds.....the ones with the hard start....that is all they do...pretty much. (BUT the usally get worse to the point where happy juice is needed to crack the truck off....then that wont even work) They dont smoke, run bad, or set codes...usally. The ones with loss of power, you see "the code" being set. Sometimes, you notice nothing and "the code" is set. I could write a book on all the symptoms i have seen when VPs die. The Cummins is a GREAT engine! The IP leaves a lot to be desired. BUT in all honesty....there are a lot of people that are running the VP with no issue. VP #2 for me is going on its 3rd year with no trouble. I figure if i had to replace it every 5 years or so...im still way ahead......but i can change them myself.....so that does knock off a chunck.......