Ok guys here a decent question for ya to maybe answer. Someone is saying that I shouldnt have pressure in the fuel tank. Is that true???

One response I got was the reason for the pressure in the tank was that one of the injectors isnt sealing. The copper o-ring that seals the injector nozzle to the cylinder head and seals compression is leaking. They stated that when one of them leaks it will allow cylinder pressure to escape into the fuel return channel in the head, the injector return fuel. This pressure makes its way through the return fuel system and then to the tank. ....Is that why i have such pressure in my tank???[coffee]

Ok guys here a decent question for ya to maybe answer. Someone is saying that I shouldnt have pressure in the fuel tank. Is that true???

One response I got was the reason for the pressure in the tank was that one of the injectors isnt sealing. The copper o-ring that seals the injector nozzle to the cylinder head and seals compression is leaking. They stated that when one of them leaks it will allow cylinder pressure to escape into the fuel return channel in the head, the injector return fuel. This pressure makes its way through the return fuel system and then to the tank. ....Is that why i have such pressure in my tank???[coffee]

the tank is vented to the atmosphere ...your vent is plugged

You are correct about the injector. We had it happen to TJ's truck when he failed to tighten down one of the injector hold downs. It was spewing diesel out the filler neck.
It's not a clogged Vent.
Get that injector washer fixed ASAP!

YES, FIX THE COMPRESSION LEAK INTO FUEL RETURN SYSTEM. Before something really serious happens.

You are correct about the injector. We had it happen to TJ's truck when he failed to tighten down one of the injector hold downs. It was spewing diesel out the filler neck.
It's not a clogged Vent.
Get that injector washer fixed ASAP!
Scottsjeeprolet, Its not spewing diesel out the filler neck, just got alot of pressure when you release the cap. Im waiting on my copper shims to come in, hopefuly this weekend![coffee]

Thanxs everybody for the info!!:cool:

Did you recently install your injectors with old washers?
Did you properly torque the hold-downs?

just my 2 cents. i had the same issue when my head was cracked. not sure if that was a result of the head or injectors like previous post. because i installed new injectors at the same time as the new head.

i get pressure in mine now and then too but it has always been like that.

mine must be working right.....i don't get a vacuum or pressure EVER!!!![coffee]

mine must be working right.....i don't get a vacuum or pressure EVER!!!![coffee]

or someone gutted your fuel cap, a properly working system will maintain a slight vacuum, its susposed to aid in allowing aierated fuel (from sloshing) to shed its trapped air.
vacuum occurs because fuel is being pulled from the tank via the LP, and when it becomes great enough the valve in the fuel cap will allow air in or else the LP would stop sucking fuel, or the fuel tank would collapse, in the event of sloshing and hot fuel (both from the return and heated by ambient air) the valve in the cap would open and expel excess pressure, ther is also a roll over valve (tank vent) that is susposed to do the same thing as the fuel cap, I tried looking it up in my repair manual, but it had nothing in there on its operation

My fuel cap has been molested, this eliminates fuel being sucked back to the tank should there be an air leak in the return side of the fuel system, which we all know can cause hard starts, or always park nose down hill

or someone gutted your fuel cap, a properly working system will maintain a slight vacuum, its susposed to aid in allowing aierated fuel (from sloshing) to shed its trapped air.
vacuum occurs because fuel is being pulled from the tank via the LP, and when it becomes great enough the valve in the fuel cap will allow air in or else the LP would stop sucking fuel, or the fuel tank would collapse, in the event of sloshing and hot fuel (both from the return and heated by ambient air) the valve in the cap would open and expel excess pressure, ther is also a roll over valve (tank vent) that is susposed to do the same thing as the fuel cap, I tried looking it up in my repair manual, but it had nothing in there on its operation

My fuel cap has been molested, this eliminates fuel being sucked back to the tank should there be an air leak in the return side of the fuel system, which we all know can cause hard starts, or always park nose down hill

Nope! i bought the truck new, i did however add an auxiliary fuel tank...the way i have it hooked up may have vented it different

http://i276.photobucket.com/albums/kk5/johnh_016/P1010001.jpg

Mine is pressureless. The fuel cap gets tested annually as part of the county emission check.

I think I might have the same issue... I installed new injectors this weekend and noticed a f uel leak.. I know my filler neck leaks a little I figure that's where the leak came from

all the old washers came out.. when I installed injector 6 the washer slid off into the injector hole as I was putting it in... I tried to fish it out with my finger but failed.. I installed the injector and all seemed to fit correctly... I was wondering if the washer is able to fall into the cylinder.. or if by luck it landed flat?

I think I might have the same issue... I installed new injectors this weekend and noticed a f uel leak.. I know my filler neck leaks a little I figure that's where the leak came from

all the old washers came out.. when I installed injector 6 the washer slid off into the injector hole as I was putting it in... I tried to fish it out with my finger but failed.. I installed the injector and all seemed to fit correctly... I was wondering if the washer is able to fall into the cylinder.. or if by luck it landed flat?
No problem as long as all the old gastkets were removed with the old injectors. I use a little dab of grease on a wooden dowel to pull the gastket out if in doubt. Or mirror and flashlight to make sure gastket is in place and lying flat on cylinders #6.

But.....did he ever check his fuel cap?

My truck has never had vacuum or pressure at fill ups.....


Cheap, easy and dumb stuff first for me!!

No problem as long as all the old gastkets were removed with the old injectors. I use a little dab of grease on a wooden dowel to pull the gastket out if in doubt. Or mirror and flashlight to make sure gastket is in place and lying flat on cylinders #6.

I noticed I had a little bit of a hard start this morning with a little puff of white smoke... now I knew something was not right...

I went back a check the old injectors I removed and they all had their copper washer... pulled the 5th and 6th injector and they both had their copper washers in place.. I reinstalled them and remembered that I had locked them down before pushing the cross over tube back in... big mistake! I dropped them in and pushed in the cross tube then locked down the injectors this time... and problem solved!

Thanks for the advice on the wooden dowel and grease...

it blows my mind that something that small has such a big impact on the way this motor runs

I agree, I have changed many injectors over the years but always double check everything before tightening down the valve cover. One loose injector bolt or nut will cause a problem down the road. Always torque every bolt to spec and follow the procedure. You'll never have a problem that way. Final torque I always use metal paint marker and just dab paint on the bolt. I do that with head bolts also. Saves time and problems later knowing it was torqued to spec..