Fuel Not Pumping, What Steps Next?

[kyfig70c20]

As I mentioned in a different thread, my truck basically started sputtering and quit running the other day just like it ran out of gas; parked it where it stopped went back later and it started right back up, went about another half mile and same thing; towed it home later that night.

Tonight, I pulled the fuel line off the q-jet and turned it over for about 30 seconds-maybe a tablespoon of fuel came out of the line which tells me I have a problem with the fuel pick-up screen, lines or fuel pump. What are suggestions for next step? I can see the fuel sending unit cover but I assume you need to remove the seat in order to remove the unit? Can I blow air back through the line to unclog if my problem is in the pick-up screen- realizing that would be temporary.

The old truck was running really good after having set for several years. Ironically, I had just left the autoparts store picking up some new lugs for new wheels, plugs etc.!!

Thanks

[68gmsee]

Since fuel pumps are cheap and the easiest to replace I'd do that first. My 69 was doing the same thing and it was a ruptured diaphragm in the pump.

If that doesn't fix it, check the fuel lines to make sure they're not restricted before removing the inside the tank sending unit to check the filter. On my 68 GMC the fuel line from the tank to the fuel pump was severely restricted. I actually had to get a new one.

fyi: take the old pump with you to compare...

[cdowns]

take the supply line off the pump blow low pressure air (no more than 20lbs) back into the tank (make sure the gas cap is off the tank) reconnect line and check to see if the pump pumps if so you've got crap in the tank problems// cheaper than replacing a pump that may or may not need replacement

[68gmsee]

I have to agree air pressure may help if it's just sediment in the line. My fuel line was restricted due to being gummed up from years of sitting. But, I disagree re: fuel pump. They are cheap (less than $20), easy to replace and if you have never replaced it or are unaware of it's condition, I recommend replacing it. I got stranded once because of a bad fuel pump. Why take the chance?

[DZL1]

I suggest what cdowns said. But 68gmsee has a valid point. You should just do both, IMO.

DZL1.

[kyfig70c20]

The other thing I discovered this morning; the two pieces of rubber hose that I could find- connected where the line comes out of the cab to the frame rail line and the supply going into the pump- are in very bad shape.

I am going to repace those as well. What size rubber is that 3/8? I am thinking about putting a filter on one of those pieces of rubber lines; what type of inline filter do you reccomend?

My guess is fuel pump is original. It was my grandfather's truck and it only has 59,000 on it.

I was feeling pretty good driving it down the road getting "the stare" and a thumbs up and then she died! My wife and kids had a good laugh.

[DZL1]

Whatever you do don't put a glass filter. As far as the size of the line, just take it with you to the auto parts store and they'll match it up.

When it comes to the wife and kids, I'm in the same boat as you. When I first bought the truck home they just laughed and didnt even want to go near it. Slowly I've been fixing her up and I always tell them that 1 day they will be begging me to take them for a ride let alone drive it!!

DZL1.

[rwolf9653]

Originally Posted by DZL1

Whatever you do don't put a glass filter.
DZL1.

May I ask why? No real reason, just never heard that.

[68gmsee]

Originally Posted by rwolf9653

May I ask why? No real reason, just never heard that.

They break. And under the cab, you can go on a gravel road and lots of rocks flying.

I have a metal filter under there. The tank had a lot of rust sediment and I didn't want to take it out and flush it. I've run about 10 full tanks through it and replaced the metal filter 3 times. About every 6 months. The last time, it looked cleaner.

[El Jay]

Originally Posted by DZL1

Whatever you do don't put a glass filter. As far as the size of the line, just take it with you to the auto parts store and they'll match it up.

When it comes to the wife and kids, I'm in the same boat as you. When I first bought the truck home they just laughed and didnt even want to go near it. Slowly I've been fixing her up and I always tell them that 1 day they will be begging me to take them for a ride let alone drive it!!

DZL1.

Don't use plastic either.
Use nothing but real steel.

[Longhorn321]

Same exact thing happend to me and I replaced the pump...didn't fix it. I have three filters...one in the carb, and two on the frame rail. The first one in line from the tank is always the problem for me. I have replaced it a couple times. I had (prolly still have) rust in the tank and I pulled the sender out to find that the sock was deteriorated and the tube was half choked with sediment. I cut the sock off and threw it in the garbage, blew the tube out good and reinstalled. So far so good. I keep an eye on the first filter (clear plastic) and if it looks like it's getting full of junk, I replace it. I always keep a spare in the glove box too.

[PanelDeland]

I would clear the line and install a filter.Then if it pumps run it.There's no reason to ruin a new fuel pump sucking debris thru it if the tank is full of gunk.Then after you have a chance to clean the tank put in a new fuel pump.If the trucks been sitting for a good while you will probably have to pull the tank to get it clean.Just put some water and assorted junk(nuts bolt and old chain work well.Then rattle it around for a while rinse and drain.Leave it in the sun for a couple days and add a bottle of gas drier or alcohol to the first tank to get the water out.You will have to remove the seat to do it but you really want it to be reliable.

[kyfig70c20]

Here's what I did; stopped at my local parts store picked up rubber line, steel filter, and a pump. Took it home ready for busy night.

1. I took the rubber lines off.
2. I then stuck a long piece of line on the steel line where it would have gone into the fuel pump.
3. I blew through like a straw but it was clogged. Blew a bunch of more air through it and it cleared.
4. I went ahead and blew air through the steel line going into the cab.
5. Went ahead and hooked everything back and tested the pumping again- IT WAS SHOOTING FUEL LIKE A SON OF A GUN!
6. Hooked up the carb again, the motor fired up and I drove it up the road.
7. I did go back and install the steel filter coming out of the cab.

I am going to take the tank out and clean it once I have a free Saturday and possibly change the fuel pump; for now I am going to take the fuel pump back.

I realize that the running may be short lived but while it was running, I am going to run it and keep changing that filter every couple of weeks! Thanks for all of your advice.

[Longhorn321]

You still have some work to do someday but at least it's running for now and you know what to do if it quits again.