No fuel getting to carb - fuel pump problem?

[engineerlutz]

Last week I changed my timing belt and replaced the coolant hoses. After i got it all together I tried to start it and got nothing. I thought maybe I got the spark plugs wired wrong but checked the fuel pump first. With a half tank of gas I disconnected the fuel line to the carb and cranked the engine for about 30-40 seconds and got no fuel to flow. Before replacing the timing belt and hoses the car ran well, though it had become harder to start the last 200 miles.

Is there anything I should try before I order a new mechanical fuel pump? I have a hard time believing the fuel pump quit on me at the very moment i shut down the car to take off the timing belt.

[bobplyler]

The fuel pump is driven by the timing belt. I would undo the fuel hose coming out of the pump, and crank the engine and see if any fuel is being pumped. Also, one time I had a fuel filter completely clog. As in absolutely no fuel going through it.

[majicwrench]

I'm wondering if pump is really being pumped. Belt turn aux shaft which drives pump.

[engineerlutz]

The fuel filter is only 1000 miles old and looks good. I can try cranking it with the hose disconnected at the fuel pump.

I talked to my uncle and he recommended making sure the fuel line from the tank isnt stopped up. He recommended using a bulb to test it. I'll try that too.

[bradartigue]

The fuel filter is only 1000 miles old and looks good. I can try cranking it with the hose disconnected at the fuel pump.

I talked to my uncle and he recommended making sure the fuel line from the tank isnt stopped up. He recommended using a bulb to test it. I'll try that too.

Just disconnect the fuel line at the carb and put it in a glass jar, then crank the car for a few seconds. If you get fuel it's pumping, if not, it's not.

[Ken]

after changing the timing belt did you hear a noise when you cranked the engine over?

[spidernut]

Here's where you should start: Make sure your timing belt did not come off. Since the auxiliary shaft which drives the fuel pump is driven by the timing belt, the pump will not work if the belt came off.

If that isn't it, remove your fuel line at the fuel pump. The supply line should flow freely from the tank to the pump. If it does not, you have some kind of obstruction. Since you have a 79, you can remove the fuel line at the tank and run compressed air (from an air compressor) to determine if the line is clear.

If the line is clear, that means you have fuel to the pump. Next, check the line from the pump to the carb. Ensure the supply line is connected to the correct opening for the float bowl. If it is clear, it is time to remove the pump. The pump can be removed and manually operated to determine if it is working.

[ClarkTheShark]

Would also be worth checking the filter sock in the tank at the bottom on the pickup. Unscrew the 6 nuts and pull it out. Those are known to clog up as well.

[engineerlutz]

Problem solved.

I started at the rear. I checked the fuel sock. Clean.
I looked under the car and noticed the vent line (the third hose going through the trunk wall with the fuel supply and return lines) was disconnected from it's prong. I had read about problems with 79's draining their fuel back to the tank because of a bad check valve and leaky hoses. The post which i cant find now said you need to crank it for at least 60 seconds to get the fuel back up to the carb.

I decided to try cranking the engine again, this time for about 60-90 seconds. It started up at almost 65 seconds. After looking at the condition of the fuel lines, I'll put replacing them on the list.

Thanks for the help all.

[engineerlutz]

Here is the post that solved my problem. The fuel was draining back to tank.

http://www.fiatspider.com/f08/viewtopic.php?f=3&t=27251

See item number 2