Idk much about the internals of the ip other than the fuel shutoff and the cold timing advance sry

 

No worries and thank you and I appreciate you getting back to me. I have asked similar questions elsewhere on this forum but no one answered. Hopefully someone out there knows the answer. I have found a lot of documents on the Stanadyne IP but it has a lot of gaps in it. As I said, I did read that the transfer pump of the IP is supposed to have certain values of pressure to work correctly but I havent found where to get the tool to check or how to check it. I am hoping once I get the E pump installed that it will fix my problem of no fuel flow in the return lines and the sluggish throttle. I am still a newbie working on a diesel but im getting the hang of it. lol

 

I'm hoping so too! I can't remember if you tested the pressure at your schrader valve while the truck is running or not but if you haven't while the truck is idling see if you have any pressure at the schrader valve by putting a tire gauge on it (it needs to be a low pressure tire gauge or it won't move it at all)

 

I did check but thank you for the advice. When I checked it, it was 3.5 lbs but that was approx 1.5 - 2 months ago. I also ordered some viton o-rings trying to find anything that is causing the problems. I am determined and thru process of elimination I will get my girl running very good again. I drug a 52 foot by 2.5 ft thick tree out of the woods today so I know she is still got muscle just this fuel flow problem is a big headache.

 

I understand because I miss my girl she has been down since July

 

I installed an electric Mr. Gasket 2.5 ~ 4.0 # pump. I Tee'd out of the fuel line before the mechanical then Tee-d back into it before the fuel filter. I use it every time on cold start-up. It's on a toggle switch and runs from 10 seconds or so before I turn on the ignition for the WTS light and let it run for around 10 seconds after the truck starts. Otherwise, it's on the mechanical pump. I over-ran the life out of a fuel filter a couple of years ago and the truck died in the middle of the road. My wife was driving and turned on the electric pump to limp home without a tow or road side repair.

 

gummy, 3.5 lbs is too low. The pressure at the schrader valve should be 5-7 psi, and should produce about 1/3 of a pint in 10 seconds.

 

Thank you for that info greywynd. I will check it again to make sure that I was correct in my previous statement. Also, I was wondering if you have ever heard of the transfer pump inside the ip going bad and if so what were the tell tale signs of such a problem. The reason for my question is I have no return fuel of any amount to really speak of. I have looked at a blow up of the inside of a stanadyne ip and it looks like the transfer pump, if it was to go bad, would go bad catastrophically which would seem to make the ip not work at all.

 

Unfortunately there aren't many people with the knowledge of the internals of these pumps, and to the best of our knowledge, any pump testing is generally done on a special stand designed for the purpose.

Some pump rebuilders won't even test used pumps, as the stands may contain a fluid other than diesel that they don't wish to contaminate with used diesel fuel, and will only test/adjust freshly rebuilt pumps.

Generally pump 'failures' on these trucks are one of two types, one from a heat issue, in which case, pouring cold water over them will get the truck running again. In this case, it's generally believed that it is a seizing problem from one part heating and expanding more than another.

The other is simply fatigue from age and too many hours, the truck slowly suffers more and more from poor performance regardless of what is done to it, replacing the injectors will help, but since this now raises the pop pressure of the injectors, the pump has to work harder, and eventually just can't provide high enough pressure to pop the injectors. At first it will start out with maybe one or two cylinders missing, and then it will grow over time.

My dually is tired in this way, at high revs it misses and carries on something awful, but as best as I can tell it has the original IP and injectors, with about 220K miles on them.

Reading back through your posts, one of your concerns is the amount of 'return fuel'. To be honest, I have no clue how much fuel returns from the injectors, and I suspect that most folks would be the same. All I care is if the right amount is getting to the injectors or not.

One simple thing that often helps with dirty/gummed up IP's is to drain your fuel filter, fill it with a cleaner such as Diesel Kleen, start the truck, run it for 10-20 seconds to fill the IP and injectors, then shut it off, and let it sit a while, ideally overnight. When you start it next time, take it out and give it a good drive, as some say 'drive it like you stole it', and often this will help free up any sticking internals in the IP, and should help clean up any injectors that can be helped too.

I know you said the previous owner told you the motor was gone over not that long ago, but it doesn't mean that the fuel system was touched at that time or not.

 

I had a idi that would not start because the pump would not deliver enough fuel while cranking.Pull start it would run fine alittle low on power but not enough fuel while cranking.Hung an injector off the line and cranked the engine over,no spray from tip.The rotor and head was worn inside the pump,also fuel likes to bypass the advance piston after alot of miles seeing the housing is aluminum causing the gray smoke and high rpm stumble.hope this helps seems odd after a fuel filter change.