Engine/Transmission (1998.5 - 2002) Hard Start when hot!!

[sstockton]

Recently my truck started having issues starting when hot. This has been going on for about 2 weeks now. Here is the story behind it. I installed a FASS about 5 weeks ago. never had any problems everything seemed fine then 2 weeks ago, I left on a road trip, and some where in there my truck started having trouble starting when hot. Sometimes it only has to crank a touch more than normal, and sometimes it cranks for approximately 3 seconds before firing. I am running injectors but those were installed well over 10k before this started happening. The truck doesn't have any problem cranking when cold. In the research I've done, DPP is suggesting that the diaphram in my VP may be damaged, is this someting I can replace on my own, or do I just have to knuckle down and buy a new pump. DPP also suggests that a way to check and see if this is the problem is to crank the truck over without cycling the pump, I tried this, and the truck had even more trouble starting.



Some people have suggested that it is because of low sulfer diesel and that I need to start running additives, what is everyones take on this. Also one last thought, could it be a possibility that the diesel I was getting in other parts of this state and out of state. I haven't filled up since I got back, but I have a feeling that is the least likely scenario. Let me know If you need any other details. Thanks and sorry this is so long.

Sean

 

[DMcPherson]

I have heard problems with thehigher fuel pressure from the fass. trucks with vp's dont like to much fuel pressure hot when they start.

 

[johncameron]

I had the same problem last summer after I installed my FASS. It turned out to be my VP-44 injection pump. After my VP died I have not had one starting issue. I'm sorry to give you the bad news :{



John

 

[sstockton]

Yeah so what I read on trouble shooting for the FASS said that the Diaphram goes out, they recommended unplugging the FASS, seeing if it would start and if so immediately shuting the truck off. I did this, and it started fine, so I am trying an oil pressure switch, that way the FASS doesn't turn on until I have say 2. 5psi oil pressure then the FASS will turn on, we'll see, I hope this helps. but my only concern is not being able to bump the start and run the pump for 10seconds or whatever it is, to prime the filters. hmm just thought of that well I'll figure something out, and if all else fails, I guess its VP time.



What are your opinions on hot rod 44's. thanks

Sean

 

[LowFly]

Another way you can go about Shutting the FASS "off" while cranking is running the sensor wire for the relay to a circut where its not hot when the key is turned to Start. (IE: your cig lighter circut) BUT this would mean that your FASS would run if you went to the ACC position on the key as well. I bet there is a circut where its only hot in "Run" and that is it. This would be the one you would want. Again... . this would mean that the FASS would run when the key was turned to Run... but most dont have it there unless they are driving anyway.



The relay sensor wire is the Red wire that goes to the stock engine harness from the realy. You put 12V+ to that wire, the FASS will run.



A note: The FASS should be pulseing (Via the Computer) while cranking to lower pressure. Check your pressure to see what you are reading while cranking. It should not be as high as normal driving.



HRVP-44's are good to about 600 HP or so..... after that..... it doesnt matter what you have... they both run out of fuel. BUT to that point, the HRVP, will eat up a stock one... ... .