Russ, Gary, Mel, fuel line help

[seawalkersee]

I have been fighting this thing for a long time and I have gotten to the point where I am stumpped.

Yesterday I finished REpopping all of the injectors and wound up replacing 3 of the ones that were less than 1k old. They were an e-bay set of BBs that I pop tested and set in Dec (I think) after getting the engine back together. Well, there are apparently at least two different styles of tips and bodies. They have a different thread pitch and different nozzle end, but back to the thread. I had some that were just ******* a stream and leaking. I swapped them out with the set that I had when I got this thing in 08. Got them all within 100 psi of them and put them in.

It ROARED to life without a lot of cranking (this is two days with the fuel system sitting open). Ran it long enough to get the air out and heat up a little and shut it off. If there is any type of heat still in the engine (warm to the touch or even sitting for 4ish hours or less) it will start with no problems.

It is in my garage which is about 60-70ish degrees. I went down there this morning and hit the key....it cranked and cranked and cranked. I stopped after about 15 sec. or so and said screw it.

There are no external leaks on this and I thoght about what gary said by putting a clear line kit on it to see if there is air getting into the system.

First question:
1)Is there a certain way the line kit has to be attached? Mine goes down the pass side from the filter head from front to rear and then over to the return line from the pump, then back to the tank. The driver's side goes back to front with only the rear injector going to the return line. The front cap is a dead head. I will try to do a diagram...

o------l---o
l l l
o l o
l l l
o l o
l l l< Had to crack this line loose
o 0/ o
l
0 ^
IP
^
Filter


So, after I get it running, there is NO fuel coming from the front two injectors on the driver's side. I took one line loose to allow all of the air to get out and put the fluid to the front injector. I let it run for a while and it seemed almost immediately that it ran even smoother as soon as the return line was full, but I am almost sure that is a coincidence. But if it is not, than I am almost sure the lines are plummed worng.

Second Question)
If I am not getting fuel to the dead head injector but it is filling the two previous lines, is there a pump problem that it is not pushing enough fuel?

SWS

 

[icanfixall]

Ok... Lets talk about the return line system and the dead headed injectors... When fuel is pumped to an injector not all of it is burned. So this "extra" unused fuel has to go somewhere... It gets returned thru the return line system to the fuel tank you are drawing from. So... If an injector isn't returning fuel something is terribley wrong with that injector. Now about having differant injector tips in the same engine... Not a great thing to do but it will run... Not a well as it could but it will run.... Its kinda like a race car running differant spark plugs and hoping to get all the power from the engine... Nope... wont happen... Somehow your getting a leak where air is drawn into the fuel system and your fuel is draining back. I don't know your fuel system so I can't point you in the direction to go... You might try removing the fuel filter when it sits overnite after you have run the engine... See if its full or missing fuel..... Thats a start.... Do you have an electric lift pump or a mechanical lift pump... If its not electric how old is the mechanical pump.... Are there any wet fittings around the fuel filter... The 3/8 line from the lift pump has an olive seal in it at the filter inlet... Then the two fittings from the filter to the injection pump has two olives in that... those are 5/16 line fittings.... Hope this gets you going the right direction...

 

[seawalkersee]

I have an electric pump. I looked at the return lines today and there was no difference. They are all full of fuel. I turned on the pump and there was no change. There is a small bubble that is in the driver's side front line and it did not move....not sure what to do from here. The only thing I can think of is that the electric pump is not pumping the fuel it should. That being said, when I hit the schrader valve on the side of the filter head while the engine is NOT running (but the key is on), it just puffs or dribbles fuel out. When the engine IS running, it dumps fuel out the side of it.

And since the drawing looks like Indian chicken scratch lets try another one


O<--injector-->O
l---------------l
O<--injector-->O
l---------------l
O<--injector-->O
l---------------l
O<--injector-->O<this one is the dead end.
l
O<filter head that has the return line go to the front injector on the pass side.

SWS

 

[Agnem]

Let me make this as simple as possible. The injectors, and the IP need to expell fuel. As long as you can trace a route from any one of these devices, to the fuel tank return, your good. It can go directly, or through any other injector or fitting in any direction. The filter head does NOT need to be connected for the truck to run if there is no air in the incoming fuel. This is NOT a permanent situation I would recommend, because eventually there IS going to be some air in your fuel, and it can only get out by going into the IP if there is no bleed off at the filter head. Reference my tech article "thoughts on hard starts and air" for more on this. Thing is, classic return line leak problems are almost always characterized by an engine that starts, but then dies immediately. Yours isn't starting. If you have smoke, you have fuel. Just not enough heat to burn it. If you don't have smoke, you may not have fuel. But remember, it can take a little while to see the smoke, so drop your up-pipes or Y-pipe to REALLY be able to tell what is going on.

 

[seawalkersee]

I have a small sectioin of clear line placed in the supply line to the filter head. I have clear lines between each of the injectors. Seems there is not a leak. I think my pump may be the problem now. I am just confused as to why the schrader valve volume increases as the engine is running as opposed to just key on engine off. Im going to check it today to see if I wired it up correctly to 12v.

SWS

 

[seawalkersee]

Another question, I DO have smoke almost immediately. If I spray it, and bump the throttle, I can keep it running. As soon as it runs for second or two, it will sustain by its self. But, if I am getting fuel, not enough to start, but enough to run, how can I rev it up and pull its self under power? Since Gary says I should have fuel heading out of the returns, is it possible that I am not getting enough fuel from the lift pump and the IP is doing more work than it should? It appears that may be the case and my fuel may have too much oil in it for 60* starts. I am going to run a line from a tank of #2 straight in to see if that makes a difference after varifying I have 12v...It appears I am narrowing down my problems...just not soon enough.

SWS

 

[Agnem]

You did bypass the mechanical pump did you not? Your right the volume and presure should not change as the engine is running under no load, unless your having a serious increase in voltage due to higher alternator output.

 

[Knuckledragger]

Your description is something that made me take apart my return lines about two weeks ago (they were leaking anyway). It does not seem that you have any problems once the engine is running, right? Bubbles in the return line are not important because they are not in the pressure system, they are just going back to the tank. If I am right so far, you need to check the GPs. The engine can get fuel and compression but needs some heat to start. I had a harder and harder time starting until it would not start without ether. Plenty of white smoke, and the engine trying to fire off, but the fuel in the combustion chambers, if not ignited, will actually cool the chamber down from exhaust scavenging.

Sounds as if your fuel system is fine, you just need new GPs.

 

[seawalkersee]

I think I have may have solved it but still have questions.

I pulled the line off of the fuel tank and put a tube straight into a container of #2. With cranking it only 15 sec and then giving the starter a rest, it fired. Died right away, but fired none the less. Now, since I have been trying to figure out where the (thought) leaks were, I have run the battery (relocating the second one so I only have one hooked up) down. I will fire it and run it pretty quick to get some fresh fuel in the IP lines and then shut it down to try tomorrow.

The GPs are good (or were a month ago). I do not think there are any problems when it is running. It feels better than ever. However, it is not broken in (remember this is a fresh rebuild) so that may have something else to add to the equasion. However, I THINK my lift pump is the suspect, as is the thick fuel that apparently is pumping very slow...I did not check the voltage at the pump, but will just to make sure. I think GenLightning has a deal on a good lift pump that will do some good pumping. I have to wonder how much better it will run with a good supply of fuel.

SWS

 

[dyoung14]

Are you ABSOLUTELY sure your glow plugs are functioning? cause if your getting smoke your getting fuel

 

[seawalkersee]

Completely sure it was a fuel issue...WAS being the operative word here. It was sitting idle for at least 4 days. Started right up like it was supposed to. Soon it will be on the road again.

SWS

 

[Knuckledragger]

Maybe a glob of jelled fuel was working its way through the system?

Good luck!

 

[seawalkersee]

Nah...after you gave it a shot, it would fire up and run, rev up and all without a hitch. It just would not start without spray. I pulled the supply out of the tank (remember it was like 60* (at most) in my garage when I was having the problems. Pulled out the supply line and ran it into my carrier of #2. Purged it and ran it for a bit. Let it sit for a few days and then it fired up.

SWS