Fuel issue?

[dremmick]

I have a 67 long box that I recently took out of storage and has not been ran in 5 years. Suprisingly the truck fired right up! I changed all the fluids and added a inline fuel filer then started the 2 hr drive home. After about 30 miles of running great all of a sudden the eingine was surging/starving for fuel. So i pulled over and let it sit for 5 mins. Then went down the rode 5 miles and did the same thing. If i let it set for 5-10 mins it runs good for only 5-15 miles.

So I had my dad run to town to grap me a new fuel pump and fuel filter for the quadrajet (inlet). Track ran great for 18 more miles then did the same darn thing.

Any idea what would be causing this? Sending unit?

[cdowns]

could be a clogged fuel sock in the tank

or it could also b a bad gas cap that is not letting the tank vent

[engineer_gregh]

I experienced the same thing with my truck when I first bought it. It had not been driven for quite some time. First thing I found was that someone had put a fuel filter underneath the truck close to the gas tank. It was completely clogged. Long story short, I replaced the tank, sending unit (came with new sock), and blew out the lines. Not good for gas to sit up for years in the tanks of these trucks.

[67 cst swb]

Check the small fuel line under the cab, that goes from the tank inside the cab then down the middle of the cab thru the floor to outside the cab and runs down to meet the hard fuel lines under the cab/frame... sometimes this kinks and after sitting, some contaminant may have got lodged in the kinked line. Over time rubber fuel hoses break down and swell closed and/or crack. So it may also be good to check all the rubber hoses.
Also... When you added the fuel filter... did you happen to re-route a fuel line over a hot radiator hose or is it laying on the motor? If so, this could be causing a vapor-lock situation

[dremmick]

thats where I put the fuel filter is right by the gas tank under the cab. Is that a bad location?

[engineer_gregh]

I put my filter between the fuel pump and carb. I don't want to crawl under the truck every time I need to change the filter. Also in the beginning I used a see through plastic filter so I could see if fuel was actually being pumped to the carb. I'm making a very frustrating and time consuming problem seem like I fixed it overnight. That was not the case. It drove me nuts for weeks before I finally ended up replacing the tank.

[SCHRUMGMC]

Sounds like the problem with my truck, it causes me some issues. It just cuts off, but then can be started back up

[dremmick]

Originally Posted by SCHRUMGMC

Sounds like the problem with my truck, it causes me some issues. It just cuts off, but then can be started back up

did you ever fix your problem? What have you replaced?

[SCHRUMGMC]

Well I am using a Boat Plastic gas tank, turned out my fuel filter was beyond clogged, and so was my Air filter.. Haven't been able to test it out due to my inline fuel filters leak. Not to mention its raining currently in my town.. I'll see if it fixes.. Was yours backfiring through exhaust and bogging down when put in gear?

I've replaced
Fuel Filter
Spark Plugs
Plug Wires
Rotor Cap
Distributor Cap
Coil
Thermostat

[dremmick]

It was bogging down only at higher sepeed 65+ mph. when it started to bog you could mash the throttle and nothing would happen. It did back fire also.

[SCHRUMGMC]

Probably another more knowledgeable member will tell you
Mine bogged down if I wanted to knock it into gear, although I have had the Carb rebuilt

[geezer#99]

9 times out of 10 a bog is caused by a lack of initial timing.

[dremmick]

but the bog is not constant. It only happens hafter driving 10-20 miles

[geezer#99]

What distributor you got?

[67 cst swb]

Well... Im not sure your fuel filter location is the problem. But that's not where I would put it. Seems to me that could possibly cause the fuel issue.
I would eliminate that fuel filter from anywhere between the fuel tank and the fuel pump.
Let me try to explain my thought on this...
Think of yourself drinking from a large cup of soda through a straw... seems pretty easy right? Now... think of that straw having a large bulb shaped bulge in the middle of it. It will take more sucking pressure to pull that soda up the straw to fill that bulbous bulged area before it can continue up the straw...
So, My mind tells me... your fuel pump is having to "pressurize" the fuel filter before it can siphon the fuel from the tank. That just may be too much for the fuel pump to do under load and/or for a longer duration of time. I think with that air pocket/cavity (that is the fuel filter itself) in the fuel line, its just not able to keep up with the volume needed.
Now... if the fuel system was a gravity fed system, as is... fuel was supplied out of the bottom of the tank and gravity was constantly able to supply fuel to the line coming off the tank... then I would be ok with a fuel filter there. But these tanks have a tube running from the top of the tank (with a tube inside that runs to the bottom...like a straw) So, essentially the fuel pump has to siphon the fuel from the tank.
I could be wrong in my thinking... but, I still would not put a filter between the in-cab tank and the fuel pump.
Also... a diaphragm style fuel pump (like the ones on our trucks) doesn't care how dirty the fuel is, it would pump mud if it were runny enough. The carb is what can't handle the dirt/contaminants in the fuel. I would move the fuel filter to a location between the fuel pump and the carb.
What can it hurt... move that filter to a location after the fuel pump and see if it fixes the problem...

[SCHRUMGMC]

Try what '67 said, sounds like an issue that needs to be resolved

[engineer_gregh]

Based on hard lessons learned. The rusty tank needs to be replaced and the clean looking one was replaced almost two years ago. I run ethanol treatment with every tank of gas. Take a look inside the neck of your tank and the inside rim of your gas cap, how does your's look?

[dremmick]

I will try what 67 said. Im using a stock Delco HEI distributor.

[imjeff]

Definitely try what 67 said. Filters are problematic on the suction side of the pump. It creates a low pressure area between the filter and the fuel pump area which reduces the boiling temp and can create vapor lock issues without much heat. Don't buy into any of the magic treatments for E10 gasoline. Nothing will prevent ethanol from absorbing water and phasing out other than using enough that it doesn't get a chance and minimizing air space in your tank.

[geezer#99]

Hei eh!!
What you're describing is related to a failing module.
They start to quit once they get heated up. Heat can sometimes be caused by low voltage.
If you don't have 12 volts to the hei the module will overheat.
Do you have a dedicated 12 volt wire for your hei?
Read about an hei module here.
http://www.crankshaftcoalition.com/w...EI_distributor

[CUSTOM/10]

I had the same issue with my old 72. Mine turned out to be the pick-up sock in the tank. Or should I say the rag that the PO rapped around the sock with a rock in it. The sock was ripped and the threads from the rag were getting sucked up into the tube partly blocking it. Running around town slow it was fine, get out on the highway the motor would starve for fuel, bog and die. Took me a bit to find that one. Before finding that I always wondered what was in the gas tank rolling around when i took a corner. ( The Rock ) "LOL"

Gary

Check the sock if nothing else works !!!

[engineer_gregh]

"Don't buy into any of the magic treatments for E10 gasoline. Nothing will prevent ethanol from absorbing water and phasing out other than using enough that it doesn't get a chance and minimizing air space in your tank."

We all have a right to our opinions. Based on two years of using Sta-Bil Marine treatment in every tank of gas the pictures I posted back up the fact there is Zero rust in the tank. Believe what you like, as for me I'll continue to use it.

[imjeff]

Originally Posted by engineer_gregh

We all have a right to our opinions. Based on two years of using Sta-Bil Marine treatment in every tank of gas the pictures I posted back up the fact there is Zero rust in the tank. Believe what you like, as for me I'll continue to use it.

If I was expressing an opinion versus a well researched fact, I would have made that clear. Phase out has nothing to do with rust. I don't use any additives and I don't have rust in my tank either. That proves nothing. Phase out happens when water, in the form of humidity or condensation, is absorbed by the methanol causing it to leave the gasoline and become a separate mixture. Since ethanol is used to raise octane, phase out lowers your octane causing more problems. No amount of additives will prevent this chemical process from happening. That's why refineries mix ethanol into the gas while it's being loaded into trucks going out to deliver. The best defense against this problem? Keep your tank full and don't let it sit for long periods of time. Science isn't really debatable. A little research will reveal exactly what I said about phase out. It's been studied...even your favorite. IMO, if you base an additive's success on whether you have rust in your tank, you're wasting a lot of cash. For my small engines and when I put an old vehicle away for awhile, I use clear gas and plain old Stabil. It does keep plain gas usable longer. As you said, believe what you want. Doesn't cost me a dime.

Jeff

[engineer_gregh]

Jeff, I don't know about Tacoma but in Nashville if you don't use ethanol treatment you will have rust in your tank. I've not used anything but Sta-Bil so I can't comment on any other treatments. I own and drive 2 71's and 1 72. Since replacing the tanks and using Sta-Bil, no more rust.

[imjeff]

Alcohol is a hygroscopic solvent. It absorbs water and cleans. The rust problem has to do with water, not alcohol. I own and drive classics every day as well. That doesn't change the laws of physics.