undate on my issues (sorry all need some help)

[punkmechanic]

Alright so for everyone that are reading this but aren't up to speed. I have been having issues with the beast. I think it is the ip going bad (it has around 140k on it) but somthing the instructor said at the ford class has got me thinking I may be looking in the wrong place.

the background is on deacceleration the truck will buck and shake at around 2100 rpm(signs are pointing towards a random miss, ie pump) but the miss also seems like air in the fuel system. I have dealt with that before and know the signs well. I dismissed it due to the rpm but the instructor mentioned a common problem on the idi's due to the plastic fuel lines, and a suction system. any small leak will cause air to go in but maybe not fuel to come out.

anyway im wondering if it could be the switching valve and its o-rings. I would think that the problem would be more across the board but if it was a small leak in an o-ring maybe it needs the aggressive negative pressure from the pump at higher rpm.

Im thinking of pulling a heavy vacuum on the system and looking for air in the lines

thanks
R. Justin

 

[typ4]

Hey there, I have a pump that is a known good unit. Also if your problem was on accell or cruise I would agree with the teach, but on decel it is most likely the advance piston. my 10 c, inflation ya know. call me tomorrow.

 

[punkmechanic]

im still gonna see about redoing the 0 rings in the fuel lines while im at it. I would love to go stainless front to rear, redo the tank switching setup, and install electric pumps in each tank, but hey money is tight and "you can wish in one hand and s*&t in the other..."

 

[towcat]

I have a segment of clear PVC hose between the bleed nipple on the filter head to the fuel return doohickey on the injector. If there is air intrusion on the supply side, the air bubbles will show up there. even if you run it up to speed and then decel and slow to a stop, there will be lingering bubbles to see. I'll snap a pic and post in a few.
the hose is a little yellowed now, but you can see through it when you wipe off the grunge.

 

[k_williams1982]

If you need a fuel selector valve, give me a call. I still have the one on the frame of the '86. I even have all the lines from the tanks to the "lift" pump on the block. Just let me know if you need them. I'm trying to get some more oil to keep mixing up my "cocktail" and since I'm laid off from work, I can make a roadtrip up to you. By the way, I'm going to mount stacks in the bed so that the kids don't burn themselves on externals so let me know what you want for your current ones when you change them out. A buddy over here has some 4.25" aluminum irrigation pipe that he said I can build stacks out of, but I haven't decided what I want to do just let.