Engine/Transmission (1998.5 - 2002) VP44 + Heat + FASS?

[BDanner]

Before I read a 17 page discussion here on fuel coolers I Googled for fuel cooler suppliers. In reviewing fuel coolers I discovered that the European diesel market is way ahead of us in turbo diesel technology. I am not implying that this is the definitive ideal location for a cooler, but I would bet that a lot of German research went into deciding where to locate the cooler on this new Audi A6 http://www.hydro.com/en/press_room/news/archive/2004_03/audi_a6_geneva_en.html . Midway down is the fuel delivery and fuel cooler. That is a slick lookingcooler!! :--)





My latest dilemma while upgrading has been the hard start syndrome suffered by many of us after a FASS install. It occurs after driving and shutting down and restarting while hot. It takes 2-3 seconds of cranking to restart I let my wife go to NY from VA with a horse trailer this weekend and showed her how to crack the injectors if she gets a serious vapor lock.



WHAT NEXT!! Each fix seems to open a new can of worms.



Most of the threads will answer your VP44 is going and needs replaced or add a fuel pressure regulator. I have not read that any of these fixes definitively cure the heat problem. It is strange how this suddenly occurs after the FASS upgrade. I contacted Performance Diesel where it was purchased and discussed my installation, symptoms and perhaps the issue of high pressure.



My gauge reads 18-20psi at idle and 15-17psi at FT. They told me that the VP44 computer is reacting and dying due to the latent high under hood temp and that a vapor lock occurs due to the heat of the fuel. They responded that they only see starting problems on VP44s that receive over 25psi. Several TDR threads suggest 6psi only for startup?



ANSWERS TO PROBLEM FROM PDR:

1. Add a fuel cooler to frame rail on return side like the Duramax.

2. Add fuel supplements to lower fuel temp and add lubrication to pump.

3. Lift hood if hot and cool if location permits.

4. New VP44 replacement





I would like to know what others have done to fix these hot start issues!



What has actually worked for "YOU" that have encountered the FASS hot start issue? 72,000 miles on second VP. Do not know if lift pump was dying because the gauges were added at the same time as FASS, it would fill the OEM filter canister after a filter replacement.



I keep dropping tons of cash in my pursuit of adding any performance box!



Bruce in VA





_____________________________________________________________



'01 3500 - DTT A/T, FASS, 4'' SS exhaust, BHAF, PSC Steering gear box, Exhaust brake, DSS, '03 link and bracket, T-Link steering conversion w/ grease fittings.

 

[keimmmo]

I don't know how the FASS is hooked up, but I had a hot starting problem when I ran a pusher pump. The factory setup runs the pump for just a moment. The gauge goes up to about 7 psi... and drops back to 0. You fire the motor on 0 pressure... after creating pressure for only a moment. As soon as the motor fires, the pressure comes up. I had the pusher hooked up on a relay that ran it as soon as I hit the key. It flooded the motor and would NOT start hot. It started FINE cold. I have put about 70k on the injection pump since I had the problem, and it is still running fine. I would guess that you have too much pressure at startup... just like I did.



Steve Keim

 

[GKinney]

hard start

Just wanted to say I have had my FASS 150 for over a year now and haven't had any hard start conditions no matter what. It always pumps up to around 15# when I first turn the key on, then drops to zero before I hit the key to start up the engine. Wish I had some answers why so many people are having trouble, it starts the same before and after I installed the 1/2" suction line in the tank. What pressure do you see after bumping the starter and let the pump run freely? Mine stays at 14-15#.

 

[BDanner]

FASS Hard start

The initial start pressure with the wait to start light is 18-19psi. I wait for it to fall to zero when the engine is warm before cranking even though the light is long off in our 85*-90* outdoor temperatures.



Bump starting the pressure is the same for the 25 seconds that it cycles.



I have bypassed the factory filter since I have the 95gph FASS with filters. I even bled the FASS filter thinking there might have been an air pocket.



As you mentioned the replacement of your tank pickup line with 1/2" hose it would be interesting to see if particular model years with 95gph pumps were having more of the hard start issues even though the 1/2" line replacement was recommended only for FASS 150 owners.



I thought I read that there are different pickups on the hose ends of certain build years as it floats the hose in order to keep it from sucking the tank bottom.



Never dropped the tank, it maybe time for a little look - see.



Another concern I have seen mentioned is the proximity between the return line and the pickup line within side the tank. Perhaps this is creating a suction and vacuum effect within certain trucks. Are all hose lengths the same inside tanks? However this would not have an effect on hot vs. cold starts.



My experience with this Dodge is that it is several cumulative things misengineering themselves inorder to give us all more to chat about!



Thanks for all replies,

Bruce in VA

 

[keimmmo]

18-19 psi is WAY more than the factory 7 psi before startup. I still have to wonder if that is the problem. Mine ran only 14-15 at start and caused a hot start problem! When I hooked up the original pump with the original wiring (only extended to the relocated pump) the problem went away... and has stayed away for a couple of years.



Steve Keim

 

[BDanner]

Thanks for your input Steve. I am almost positive this hard-hot start is pressure related. Several old threads mention that reconnecting the factory LP resolved the hot start and when they reconnect the FASS pump it is hard start again.



I liked the idea of the pusher pump vs. LP and having read plenty of praise about the FASS I was sold.



Today I am rethinking my investment as it appears to not be a plug and play modification as heralded.



Bruce in VA



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2001 3500 "Still getting the Dodge out of the Cummins"

 

[JimKing]

I had a hot start problem after installing my FASS, I cured it by adjusting the running pressure downward until it was at 14-15 psi. Where I live it gets HOT. . With the stock setup as the FASS was delivered it had 19-20 Psi running, but it would refuse to start hot. Brad sent me a new spring that was about 12 Psi running and it started fine regardless of the temperature, but I could pull it down to 8 Psi WOT, so I stretched it a bit and found my "sweet spot" was right at 15 psi. Starts great regardless of temp. I have talked to others who have tinkered with the pressure and found it to be different for their particular setup. Do a little experimenting, lowering the pressure is as simple as squeezing the spring in a vice, or have them send you a lower pressure one, then work around that. IMHO, every setup is different. One thing certain, to much pressure will make it hard to start. I read somewhere here that Cummins ? or Dodge ? or someone says that high start pressure can damage the VP44.

 

[keimmmo]

Well, the FASS sounds good in general, but I was never sold that it was worth the investment. Is there a way to hook up a resistor to make the FASS run slower and make less pressure on the start cycle but still deliver good pressure when running? I honestly don't know enough about the electrical system to know if it is possible or not... I'm just thinking.



In thinking back to when I had my hot-start problem, it was Scheids in Effingham, Illinois who told me that anything over 7 psi before startup can cause hot-start problems.



Steve Keim

 

[Hohn]

WHAT NEXT!! Each fix seems to open a new can of worms.

First rule: quit fixing things. It the number one rule of Holes. If you find yourself in one, you put the shovel down



Anyway, your FP seem in line and the difficult starts when hot is a CLASSIC dying VP44 issue.



It may just be my ignorance, but the fuel cooler didn't look all that impressive to me.



jlh

 

[keimmmo]

If the hot-start were with near factory fuel pressures, I would say the VP is dieing. But, the high fuel pressure is a concern to me. I had hot-starting problems 60k-70k miles ago. Fixing the high fuel pressure solved the problem. Now, are you going to tell me that my hot-starting problems were due to a dieing VP? I still have no codes, the truck runs and starts fine, and I am getting better fuel economy than when new. It also seems odd that the problem started when the FASS was installed and the fuel pressure was increased. COULD be a coincidence, but I doubt it.



Steve Keim

 

[JimKing]

I gotta agree. However, Hohn's advice is well put. If you find yourself in a hole, you better start filling it in. Go back to where you started and work forward from there. There are many examples on this board of folks who developed a hot start problem after making changes to the lift pump/fuel system in general. There are just as many solutions posted. Learn from those that had similar problems before you. Oh yeah. . VP's don't always throw a code prior to going belly up. . My brothers 00' barely ran when he had a pump replaced. Never a code, until he fired it up after the replacement.

 

[tractorface]

Lots of good advice. I would also suggest checking the vacuum on the suction line to the tank. This is often overlooked, however the OEM fuel module has been known to be overly restrictive. A real strong pump like the FASS can suck the fuel out of the module if it is marginal. GKinney and others have installed 1/2" suction lines to cure the problem. Actually 3/8" is more than enough. Just want to keep the restriction low

 

[BDanner]

Hohn thanks for the putting the shovel down advice! Two questions for you:



1. I would appreciate your expertise and wisdom in the addition of a fuel cooler. Not for solving my hard start issue, but in general for the overall well being and long life of the VP44. Would you use one and if not, why?



2. If so would you place it before or after the injector pump?



I placed that Audi A6 link in my post at the beginning of this thread not for the actual Hydro fuel cooler product, but for the location that the Audi engineers chose and their recognition of high temperatures generated by high pressure inline injectors. There has been alot of discussion on the need and or placement of a fuel cooler.



Thanks,

Back to one step at a time, shovel down for the moment.

Especially with my freshly broken right wrist. :{



Bruce in VA

 

[tractorface]

Fwiw

We see hundreds of Diesel generators every year and I have never seen a Fuel cooler on anything but the return line.

 

[BDanner]

Fuel pickup module

tractorface I really like that custom fuel pickup module. Checked it out in your rig gallery! Nice work.

 

[Rebel Ram]

My experience with FASS.

I bought my FASS as a vane first step in trying to save a dieing VP44. My fuel pressure was very low. (9psi @ idle & 0 @ WOT) I knew that the factory lift pump was junk and buying a new one was to be buying new junk. So I reckoned that if the FI pump was good or bad the stock lift pump had to go and a higher volume and pressure fuel supply was necessary anyway. After installing the FASS system I experienced one time only on the old FI pump a hard start episode. But that was only because I had been bumping the starter to hold pressure. Turns out my VP was bad anyway and after I installed the new one, Viola, No problem.

I am not suggesting if you are having hard start problems, that your IP is bad but, rather you may have high fuel pressure @ start up as mentioned in earlier posts. In that case I urge you to check installation and opperation, specifically the power supply to the FASS pump. It plugs directly into the factory loom and as with the stock lift pump, It will only run for approx 3 seconds and then shut off if the key is turned to the run position only. This is controlled by the truck computer through the stock fuel pump relay in the power distribution block under the hood. (fuse box) This is what your FASS should be doing as well. If the pump remains on as you are trying to start you engine, then you have a high pressure problem. (perhaps)

Give it a look.

 

[tractorface]

Thanks, my only wish is that I would have used a different material. No problems but I worry about rust. Mabe next time :-laf

 

[BDanner]

Pulled the FASS fuse!

Got a hold of the guys at FASS and they told me to pull the fuse and crank the engine over when the hot restart issue arrises. Well that is everytime when the outside temp has been 85*+.



Guess what it fires right up with the VP sucking on it's own. I snapped the fuse back in and off I go. They said they will send a lower pressure spring to replace the one in my FASS. It seems as I was told in an earlier reply in this thread that the trucks are all very individual and they will react to high pressure accordingly. The spring inside these pumps appears to be something they know about as an issue creating a hard hot start. It may be a death watch on this VP44, but if the spring is the band-aid I'll wear it for as many miles as I can.



I am still contributing to the Hot rod VP insurance fund as I know that one is always driving with one foot on the gas and the other in the VP grave. I am also adding a diesel additive called DIESEL AID made by E-ZOIL for cleaning and lubricating the injection system.



Thank you for all the help!

Bruce in Virginia