Humblecowboy

New thread from my "fuel heater leak" topic since this doesn't concern the fuel heater.
That link is here:
https://www.dieseltruckresource.com/...k-t279886.html

Posted: 01-03-2013, 07:47 PM . . . I may not have bled all the air out because my engine hi-cups a couple of times when I start it after it has sat over night. After that, it runs fine. Guess I'll try bleeding it at the injector pump to see if that does any good.

Humblecowboy

Well, it is still cutting out a couple of times about 5-10 seconds after a cold start (sitting overnight). After that it's fine and idles and excelerates normal. Starts fine even after sitting a few hours. I went ahead and bled the line at the vp-44 banjo but I didn't get a flow after two lift pump cycles. Put a bleed line on the outside test port on the filter header and got 4 oz. per pump cycle. It is an oem pump that the mechanic put on after the ip replacement. I'm baffled as to why I didn't get a flow at the ip banjo??? I've got fuel flow because the darn thing cranks up right away. I'll try the cold start tomorrow and see if I fixed the air in line problem. According to Bluechip's site, my symptoms are air in the line. It didn't start this until the second time I replaced the fuel heater o-ring. A Checked all the fittings and all are tight. If this doesn't work then I guess the next step is to replace the copper washers on the header banjos as I may be getting air there. Want a fuel pressure gauge real bad but can't spend that much right now as I am about retired out and not real sure yet of what kind of budget we'll have. There are mechanical gauges cheaper and I may mount one of them under the hood just to monitor pressure for now. It should plumb into one of the header test ports easy enough. "Stay tuned for more details".

rickf

I have had problems in the past with reusing the rubber/metal sealing gaskets on the banjo's. Only on the suction side. They never seem to leak easily on the pressure side but I have had issues just like yours due to the one coming into the pump leaking and sucking air.

Humblecowboy

Thanks Rick. I'm still getting the cutting out a few times right after a cold start so my first process of elimination will be replacing the copper washers on all three banjos, The one leaving the filter header tp the ip seems to be made of some composite material and is probably the OEMs. The other two banjos are copper or brass. I have an assorted box of copper so I hope I have the right size, otherwisw, it's back to the parts store. The leaking around the fuel heater is solved so far so I wouldn't think it's sucking air from there. When it was leaking fuel I didn't have this problem. Go figure??? Did you use copper on your ip banjo?

rickf

Back when i was having that problem I was using the stock sealing washers which were rubber over metal. Now I have mostly the copper washers that came with the new lift pump. Your leak could be anywhere along the suction side of the line and you would never see a leak since it is under vacuum while running and even when you shut it off the fuel trying to run back to the tank will keep it on the negative side so if there is a leak it will draw in air as it sits and when you first start it it gets that one big hit of air and after that the leak is so small it is not noticed.

Humblecowboy

OK, I'm confused but at my age that happens a lot more frequently. When you say "suction side" does that mean before the lift pump or between the filter head and the ip? The line to the ip has a short section of hose, for what reason, I don't know. It would seem to me that the air is entering close to the ip since it starts cutting out about 3 to 5 seconds after it starts and it does start right up on the first rev or two. There's no hard start. Is it possible that the fuel pump pressure pushes the air to the head of the line? Sorry for my ignorance on this truck but I'm learning as fast as I can and especially when it comes to an injector pump that costs almost as much as an engine in some cars. I'll have to drive it like it is until the weekend when I can tear back in to it and put in new washers. I just hope I'm not doing any damage.

rickf

You are correct in your thinking. The suction side is anything from the tank to the pump and pressure side is anything after the pump. High pressure is after the injection pump. What is happening is not going to cause and severe damage. As long as you are not standing on the throttle when it burps you are fine. There is a way to check for air, take a piece of clear flexible line from the hardware store and put it in place of the rubber line from the filter to the injection pump. Clamp it very well! (don't ask) You can even put a loop in it to give you a little more viewing space. Have someone else start the truck while you watch the line. If it is building up a large bubble you will see it come through. Remember that when you first put the line on you will have air so that will need to be worked out and then let it sit the normal time and try it while looking at the line. Even after it is running smooth watch for a steady stream of small bubbles, if you see that then you have a leak somewhere on the suction side. Keep in mind that this clear line is not rated for diesel and will break down in a couple days so do not leave it on there for more that a day or two. I would advise getting a size that is a bit too small so you have to force it onto the metal lines. Otherwise it will leak and tend to slip off.

Rick

Humblecowboy

Thanks Rick. I will do the clear hose test this weekend. The only thing that has me baffled is that I didn't mess with anything from the filter back to the tank unless it just started coincidentally.

nothingbutdarts

Out of curiosity, try cycling the ign. key on and off 3 times, each time waiting till the lift pump quits pumping, then try to start it and see if it stumbles.

Humblecowboy

I'm sorry nothingbutdarts, I posted this on the 29th but in my original thread "Fuel heater leak" I guess I'm an official senior citizen since I can't remeber when,why or where I post, among other things "un-remembered".

Posted on the 29th:
Well, I said a prayer on my way out to start the truck Wednesday morning and sure enough, it started and ran fine to work and back. Did the same thing Thursday and today. I don't think it was anything I did so it had to be a miracle. Evidently there was quite a bit of air trapped that I wasn't getting out on the bleeds. Thanks for the suggestions and help. Now on to another thread for TLC that I need to start giving this old gal because she has to out last me.