Fuel Issue - My first time stranded by a Fiat

[69Spider]

Please help point me in the right direction; my wife was not impressed by being stranded our our Sunday drive, I am trying to get her to enjoy this car, but I am not "Winning!". '71 Carbed.

Sypmtom 1: If the car sits for a few days, I have to pour a little gas down the carb in order to start it.

Sypmtom 2: Car started to bog a bit at low speed (in 1st gear), I dismissed this as tall gearing. About 5 minutes later it stalled and would not restart, so I had to tow it home. I could get it to start with a little fuel down the carb, but it would shut off after this was fuel was done. I looked and found two fuel filters, one before the mechanical fuel pump and one after the fuel pump. I disconnected the fuel line at the carb and cranked, no fuel came out. I removed the filter after the pump and fuel came out. The filter did not seem to be plugged as I was able to blow through it easily. I reconnected the filter and now fuel flows out when cranking the engine. I reconnected to the carb and still the car would not start. I looked down the carb and did not see any fuel entering the carb when the accelerator pedal was pressed.

Any advice on how to resolve this fuel issue would be much appreciated. Also, are the fuel filters correctly located?

[jctucker]

Check out my thread 'Fuel delivery issues' for some ideas. I haven't completely resolved it yet, but have the exact same symtoms you do.

Try applying a little air pressure to the gas tank thru the filler neck. This got mine started and it ran for a couple days after this.

[azruss]

there should be a 17mm wrench size brass bolt on the underside of the carb where the fuel comes in. that gains access to a mesh screen. see if that is full of crap. if you didnt get fuel to the carb until you messed with a fuel filter, it sounds like that needs to be replaced. could be junk in the gas tank came loose and clogged everything up. blowing thru the filter just means the junk settled out of the output hole but will eventually clog it up again.

[So Cal Mark]

there really is no reason for a filter on the inlet side of a mechanical pump. On a lot of the older cars, we find original fuel hoses from the tank to the hard lines. Those lines can suck air so the pump can't pull enough fuel.

[jctucker]

there really is no reason for a filter on the inlet side of a mechanical pump. On a lot of the older cars, we find original fuel hoses from the tank to the hard lines. Those lines can suck air so the pump can't pull enough fuel.

Mark, I was hoping that's what my problem was too. I replaced the rubber line from the sending unit to he hard line and then from the hardline to the pump. No help.

69spider: Take a 3 feet length of fuel line and attach one end to the inlet side of the pump and then stick the other end in gas. Try starting it. Mine fired right up.

[majicwrench]

I have a fuel filter before my pump on my 64 Chev PU. Keeps the rust from getting in the pump. Once rust is in pump, it gets under the check valves and the fuel drains back and the pressure isn't as good.
If you have a rotten tank, a filter before the pump is a good thing.

PS I had the change that filter--the one before the pump--every couple weeks for the first year or so I drove that truck. Now it lasts for years.
Keith

[So Cal Mark]

There is also a short piece of flex hose near the left lower suspension arm in the rear. That piece is often overlooked.

As for the filter before the pump to catch rust, that's a band-aid. If your tank is that rusty, fix it.

[scarlson]

I just solved an issue like this with my spider. It turned out to be a piece of bark/wood plugging the pickup tube. I had to pull the pickup assembly/fuel sending unit from the tank and blow through the tube to clear it out. I've made it 60 miles without any issues since fixing this.

[rlux4]

You gotta quit using the Spider to do your logging with!
Ron

[jctucker]

I just solved an issue like this with my spider. It turned out to be a piece of bark/wood plugging the pickup tube. I had to pull the pickup assembly/fuel sending unit from the tank and blow through the tube to clear it out. I've made it 60 miles without any issues since fixing this.

?!? Whoa.

I replaced that short peice of hose near the suspension too. Are there any rubber lines inside the body channel where the hardline disappears into?

[scarlson]

You gotta quit using the Spider to do your logging with!
Ron

I'm pointing my finger at the previous owner on this one. There was a lot of pine needles in the wiper motor area.

[Danno]

I agree with no filter prior to the pump being proper. Pumps are best at pushing, not pulling, if that makes sense. Putting any restrictions before the pump will reduce life and effectiveness.

[69Spider]

Thanks for all the great info. I will keep plugging away at this issue and post when I resolve (if I can). I agree with removing the filter ahead of the mechanical pump, after i can ensure that the tank is clean. The bigger issue will be convincing my wife to go for a drive again, since she hates getting stranded.

Can anyone explain why there are so many fuel lines, and what is the purpose of the vapor filter in the trunk, can all of this be simplified with one fuel line to carb and one return line to tank?

[Danno]

Try 8 months preggo and 100 degrees out. She hasn't been in mine since. That was almost exactly 3 years ago. In her defense, I still haven't fixed the problem, lol. (alternator)

[Carsonh2]

Been having similar problems with my 79 that's been outfitted with an electric pump mounted in the engine bay. If I blow air into the filler, you can hear the gas feed into the pump and it will start without issue. If I don't do that it just clicks like it is getting air or not getting fuel. Once the car has warmed up it has no problem starting or running. I replaced the fuel pump that it had when it died a couple weeks ago (we were temporarily stranded!) but since it isn't standard to have the electric fuel pump,there is no direct replacement. Ive changed out the lines and that didn't change anything. I'm thinking the pump I got may be too high pressure, but not sure if that would be the cause? Would getting a regulator or lower pressure pump fix the issue? Thanks guys!