Still full of air

[offroadohio]

New fuel tank sending units, new fuel tank selector, new return line kit, new lift pump, new steel/rubber fuel lines. And the truck STILL fills with air. I wasted about $600 so far trying to figure this out. I had this SAME problem with my 93 and its why I sold it.

Only thing not new is the injector pump, and the hard plastic lines.

Where in the heck is this air comming from?

 

[6 Nebraska IDIs]

We had an injector pump go bad that caused this.
Dont know if its your problem but it could be. Not much else it could be.

 

[offroadohio]

I had this SAME problem, on the engine before tis one (it blew up) This enigne didnt have this problem in the truck I pulled it from. Leads me to believe it isnt the IP, but I could be wrong.

 

[oregon-mike]

How about going electric on your fuel pump? Never any worries about air in the lines with that setup. An electric is on my list when my lift pump goes out for sure! Fixed *loads* of problems I had with air in my old 6.2 Chevy too.

Mike

 

[offroadohio]

Been wanting to do that, but that still doesnt find out why its getting air.

Once it gets air, it takes 3 battery cycles ( drain/recharge) to get it cranked enough times to fire up. That tells me there is a major air leak someplace.

I'll probably by a pump tommorrow, and install it. I cant leave for WV until its fixed.

 

[oregon-mike]

One of the steps I did when attempting to find the air leak in my old 6.2 chevy was to buy a cheapy plastic gas cap, drill a hole in it, mount a tire stem in it and pressurize the entire tank/system to 3-4 psi. I had a pressure gauge plumbed in at the primary filter on the firewall to make sure I didn't go too high and blow up the tank. I left it sit for 24 hours, still held the 4 psi, no runs, no drips, no errors. That's when I gave up & did the electric pump.

Good luck,
Mike

 

[Greenbeast6.9]

i had the sending unit rust on top of the tank where the lines connect and leak there, i took 3/8 fuel line and clamped it on and it took care of the problem fully.

 

[Exekiel69]

The electric pump is something that will solve many problems but You can still follow the fuel lines and see if any is rusted by chance. Some times is as easy as a kinked rubber fuel hose. Check the olive rings before the filter if You have any. Also the o-rings on the fuel selector valve.

 

[BROWNIEBOY525]

does your truck have those plastic quick connects the conect the fuel line to the sender. if so these tend to leak over time. thats what was wrong with mine

 

[Agnem]

Replace some of your fuel return lines with clear vinyl hose. Especially the one that goes to the fuel filter head. This will allow you to see what direction the air is coming from, and will help you troubleshoot this.

 

[offroadohio]

I put the electric fuel pump on this morning. Went rather easy, as the factory holes in the frame jsut in front of the selector matched my pumps holes perfectly, so there was no drilling required. I simply cut the hard plastic line and boiled some water, and dipped the ends in the water, this allowed me to easily push the line onto the pump, I then installed hose clamps just as a precuation.
I removed the end fitting from the line running from mechanical pump to filter, and hooked the factory rubber line (after inspecting it for cracking) up to that.

Ran pump on a 15amp fuse to an unused port in the fuse box, that gets power with the key. turned the key on and let it pump about 15 seconds until the pump quieteded down, then I turned it over and it came to life easier than ever before.

Now, my only question is.

Will it hurt running it with mechanical fuel pump still bolted in until I find a cover?

I believe I read I must use a BB chevy cover? Are the sbc covers differant?

 

[oregon-mike]

Everything I've read says remove the mechanical pump when going electric. If the diaphragm fails you'll fill your oil pan with diesel.

I'm guessing BB Chevy plates are bigger but I have no idea, all I know is that everybody says use a big block Chevy block off plate.

Cool beans on getting it installed & running!

What pump did you buy? How much$?

Mike

 

[Agnem]

I think what he means is can he use the fuel pump as a block off plate. I don't think he's running any fuel through it. Yes, you can, but I would get the block off plate ASAP.

 

[offroadohio]

I have the block off on order, just wanted to make sure my small huals this week wouldnt hurt with the mechanical pump running dry.

I went in and bought the 6-9 psi pump with built in relay for $44, the fittings that came with it slide right into my hard palstic lines, after I heated them (the lines) with boiling water. Didnt have to drill any holes either.

I ran it yesterday and today with no issues other than the now dragging starter. Starters dont like to be red hot. Its still under warrenty though so, a replacment is on order aswell.

 

[Wanderer-rrorc]

SWEET!!