Fuel Problems?

[GKsport67]

Do they have a fuel filter between the gas tank & the fuel pump? Where would a fuel fiter be in a 67 chevy pick up?

[highperf4x4]

If someone added a filter it could be anywhere but all you have to do is track the fuel line.

You should be able to see one under the hood though between the fuel pump and the carb. If you have a Q-jet there should be one inside the inlet fitting on the carb too.

What problems are you having?

[GKsport67]

I was driving & it just cut off. In the picture,the fuel pump is mounted on the back of the A/C wall with the RED strip around it.I took the hose off from the fuel pump & the gas was flowing freely,now its trickle'n.

[cdowns]

in the tank on the fuel pickup theres a coarse fuel sock that is not uncommon for 40years of crap to gum up

[68gmsee]

Yeah, it could be anywhere if someone added one in the fuel line. Originally they had only the sock inside the fuel tank (which can get clogged up) and the one inside the carburetor where the fuel line connects.

I place one under the truck before the fuel pump cause my tank had a lot of sediment in it from sitting.

[Boog]

Take the supply line off the pump and blow back through it. If the in tank screen is clogged up this might free it a bit. Then reconnect it and see if it flows any better.
Also isn't that pump mounted kind of high? I've been told numerous times it's easier to push gas than to pull it so with it mounted high it has to work harder to get the gas up out of the tank and pull it up to the pump. I'm not bad talking your work just asking cause this could be some of your problem. I think the pump needs to be lower than the gas tank.

[highperf4x4]

Originally Posted by Boog

Take the supply line off the pump and blow back through it. If the in tank screen is clogged up this might free it a bit. Then reconnect it and see if it flows any better.
Also isn't that pump mounted kind of high? I've been told numerous times it's easier to push gas than to pull it so with it mounted high it has to work harder to get the gas up out of the tank and pull it up to the pump. I'm not bad talking your work just asking cause this could be some of your problem. I think the pump needs to be lower than the gas tank.

Yeah the fuel pump needs to be low.

I'd be surprised if it was the sock. Generally that's a slow process. You'd probably start losing fuel under hard throttle but run ok at an idle. If it just keeeled over going down the road I'd be looking at the pump.

[GKsport67]

Originally Posted by Boog

Take the supply line off the pump and blow back through it. If the in tank screen is clogged up this might free it a bit. Then reconnect it and see if it flows any better.
Also isn't that pump mounted kind of high? I've been told numerous times it's easier to push gas than to pull it so with it mounted high it has to work harder to get the gas up out of the tank and pull it up to the pump. I'm not bad talking your work just asking cause this could be some of your problem. I think the pump needs to be lower than the gas tank.

I bought it like that. I'm just trynah solve the problem. I got some good leads,thanks guyz. I lot of people love my truck but they don't know wat it is to have it. it's kool though.

[GKsport67]

So the pump i have sucks the fuel from the tank? do they have a filter or another pump from the tank to that top mounted fuel pump i have? What is a sock? can u show me somehow?

[highperf4x4]

A sock is just a screen inside the tank on the fuel pickup line. You'll know it when you pull it out.

Any fuel pump sucks fuel from the tank. Even the factory mechanical pump. Whether or not someone put a primer pump in the tank is impossible to know until you look. It's not stock. It's a modification that someone made themselves.

[GKsport67]

How you take the sock off? Where is the sock mounted? I will blow back on the tube that runs to the high mount pump.

[highperf4x4]

If your truck has the factory tank behind the seat then you will pull the section that the fuel lines are coming out of. The sock will come out with that unit.

[GKsport67]

Oh,its like a bag that catches trash. i got some catalogs that may have a photo of it thanks!!

[Rack Man]

They just slip over the pickup tube on the tanks sending unit...I just replaced mine...it was disenegrated

Here's what they look like....and here's where you can buy em...

http://www.americanclassic.com/asp/d...ype=to&exyear=

[LAW51]

My stock 67 had a fuel problem. One of my buddies told me that his 72 had a fuel filter under the tank on the frame. Sure enough, mine had one too. I put a new one on it and the truck has run like a champ since.

[GKsport67]

Originally Posted by LAW51

My stock 67 had a fuel problem. One of my buddies told me that his 72 had a fuel filter under the tank on the frame. Sure enough, mine had one too. I put a new one on it and the truck has run like a champ since.

on the frame? can i get it @ the local parts store? The sending unit is non existant @ auto zone,advance auto & orielly's.Did u remember the cost?

[riche]

One thing you could do real quick is rule out the fuel pump. Go get a few feet fo fuel line and get a small gas tank run the line from the small tank to the fuel pump. if the truck starts and runs the pump is fine. and the problem is in the lines/tank. if it doesn't run then the pump or the regulators history.

[GKsport67]

Well guyz i blew back on the hose coming from the tank & still the same situation. so i think the sending unit may be faulty. I didn"t find the filter on the frame either. So...its For Sale

[GKsport67]

Thanks 67-72 family! im tired man,i invested $3500+ & still can't get no act rite.

[riche]

don't throw in the towel yet!!! Rule out the pump then work your way back.

[GKsport67]

i will work with that sending unit & its parts in the am.

[Boog]

Originally Posted by GKsport67

on the frame? can i get it @ the local parts store? The sending unit is non existant @ auto zone,advance auto & orielly's.Did u remember the cost?

You won't need a "sending unit" anyway. That is the float mechanism inside the tank that measures the gas level for the gas gauge in the dash to register. The only thing you might need to go into the tank for is to replace the screen or "sock" on the bottom of the pickup tube. You blew back through it and it didn't help right? Does gas come through that line from the tank to the pump ok?
It's the line coming from the pump to the carb that is only trickling right? If so then you'll need to look at that pump closer. Just because it runs doesn't mean it is pumping enough pressure. Your engine needs no more than 6.5 to 7 psi fuel pressure. More than that and the gas will push the carb float down and flood the engine. That's what the fuel pressure regulator is for. Can you hold your finger over the end of the fuel line running from the pump to the carb and tell if it's got much pressure? What kind of carb does it have? Have you looked in it for a filter?

[highperf4x4]

If you have an electric pump on a carbureted engine that doesn't want to pump fuel and the line going back to the tank blows clear then you probably have a bad pump, a bad relay, or a bad pressure switch.

[rico7769]

I had a similar problem w/ mine when we installed an elec pump in the engine compartment and mounted it on the inner fender. Worked great for about 6 mos, then slowly lost from 7psi to 5, then 3, then nothing. Start up after a few days and same repetition after about 10 mins. Checked the regulator, checked the pump, nothing. Replaced w/ a mech pump and had the same issue. Simple things generally solve the problem. We pulled the sending unit and found the pickup tube clear of debris, followed the hard line throught the floor and found and unreplaced piece of fuel hose that connects the line from the gas tank through the floor to the line that runs down the frame up to the motor compartment. Replaced the line and found that it was collapsing and clogged. New line=consistent PSI and no probs since then. Cost $2. Like the previous post said, chase the line all the way in sections back from the carb to the pump, pump to the hard line in the frame or filter, then back to the tank supply line and then the sending unit. Its possible that the tank needs to be cleaned out too. Might be debris from 40yrs of corrosion and junk. Good luck.

[GKsport67]

Thanks Guyz! i will let yall know the results later.