Update on the fuel problem

[Low87]

RE: http://64.246.42.114/vboard/showthre...threadid=89984

I checked Chris & Mike's suggestion to unhook the inlet to the TBI and see if any fuel came out when I tried to start the truck, nothing came out. I then took out the fuel filter, it was clear. I put the air compressor line to the TBI inlet to see if anything would blow out to where I had unhooked the filter, nothing came out. I then drained the fuel tank (about 8 gallons in there) and pulled out the foam. I ran the air compressor to the other side of the filter hookup, the air ran through the fuel pump and to the fuel cell without any apparent obstruction. Right now I'm letting everything drip and air dry.
Any ideas what the problem might be from these findings? The fuel pump is brand new with less than 50 miles on it.

[swervin ervin]

If I'm reading this right, it sounds like you have a plugged fuel line somewhere.

[Captkaos]

Does the e-pump pump any gas at all? I believe that the pump will have a one way check so the fuel won't go backwards, but I could be wrong. Can you presurize the tank and get anything out with the pump gone? How about blowing air on the other side of the filter to the TBI end?

[Free88]

sounds definately like a fuel obstruction. May have a blockage in a hose or a weak spot in a hose that may collapse. Secondly I would check and see if the fuel pump is putting out its correct volume, or if it is even getting correct power to it.

[swervin ervin]

Yeah, what he said.

This may sound like a dumb question, but the fuel pump is working, right? Do you hear it running?

[mike reeh]

is your fuel pump relay clicking on? Can you hear the pump running in the tank? If its working you WILL be able to hear it standing next to the tank (have someone else turn the key to ON)

I didnt read all of that other thread but thats my suggestion.

mike

[Free88]

Should be able to hear it. The one on my 2000 Safari is so loud you can hear it from 20 feet away. My brothers 87 Blazer just had this problem and I talked to him and he told me that it was a bad ground on the wiring. Cleaned up the connections on the pump and it worked. Just my second thought.

[Low87]

Originally posted by Captkaos
Does the e-pump pump any gas at all? I believe that the pump will have a one way check so the fuel won't go backwards, but I could be wrong. Can you presurize the tank and get anything out with the pump gone? How about blowing air on the other side of the filter to the TBI end?

Not sure if the pump is pumping gas, but it is running. Before I emptied the tank I should have disconnected the hose right after the pump to check if anything was coming through there. Not sure how I'd be able to pressurize the tank. I'll check blowing air from the filter location to the pump tomorrow, seemed to work okay today in reverse (from TBI to filter location) but I'll double check that as well.

[Low87]

Originally posted by Free88
sounds definately like a fuel obstruction. May have a blockage in a hose or a weak spot in a hose that may collapse. Secondly I would check and see if the fuel pump is putting out its correct volume, or if it is even getting correct power to it.

I can't find any weak spots, all the line is either factory steel line or recently installed stainless braided hose. The pump does have power to it, not sure of volume.

[Low87]

Originally posted by swervin ervin
Yeah, what he said.

This may sound like a dumb question, but the fuel pump is working, right? Do you hear it running?

I do hear it running, like I've said, it's a new aftermarket pump (not in the tank). It primes as soon as I turn the key and keeps running for a couple seconds after I turn the ignition off.

[74Pumpkin]

I had a similer problem. The pmp ran dry for just a short time and it burned up the impeller. It ran fine, just could not create pressure to push the fuel. Something to watch for.

[apstguy]

Just a thought - but is the fuel pump wired backwards so it runs in reverse?

[Captkaos]

Originally posted by Low87
Not sure how I'd be able to pressurize the tank.

Get a rag/towel and wrap it around the air nozzle and stuff it against the fuel filler hole.

[Low87]

From all I can see everything looks okay. The only thing I can narrow it down to is the fuel pump. Tomorrow I'm going over to the shop that installed it to ask about a warranty. Now that the tank is empty and everything is disconnected, are there any ways to test it? It didn't pump anything the 4-5 feet of line I had on it yesterday.

[Captkaos]

Originally posted by Low87
Now that the tank is empty and everything is disconnected, are there any ways to test it?

As in test the fuel pump? You can stick a hose on both ends and submerge it into a gas can throw some juice to it and see if it will pull the gas out.

[Mike76251]

Unless a new type of foam has been invented and they didn't tell me.............LOL
NEVER get tank with foam in it.
The foam breaks down real quick and once it does, there is no easy way to get it all out of the system.

[Low87]

So you suggest I leave it out? Anyone else with thoughts on this? I'd thought of that too Mike.

[Captkaos]

Originally posted by Low87
So you suggest I leave it out? Anyone else with thoughts on this? I'd thought of that too Mike.

I was going to leave it up to you, but since you ask, for a street vehicle and as much trouble as you have had with it, I wouldn't put it back in FOR you if you paid me.