New fuel pump, no fuel

[archiethe3rd]

I've owned my 78 for about 2 1/2 years. About 1 1/2 years ago after driving it fairly often it stopped on me. Luckily two friends spotted me on the side of the road and helped me push it to where my business is and could let it sit fenced in. Periodically over the next 3 or 4 months I would try to start the car. Sometimes I would crank and crank and nothing, but other times it would fire right up and run just fine. One day it would start, the next day it wouldn't. Finally as fall approached it started one day and I drove it home to my garage. It ran great. Being a novice, I suspected the fuel pump and installed a new one and now I'm getting no fuel to the carb.

I've replaced most of the rubber fuel lines and filters as well and blown air through the lines. I am getting fuel up to the pump but none beyond that. The car starts and runs when I pour gas in the carb. The new fuel pump was set up just like the old one but I am at my wit's end on this. Any help, questions, observations and answers are appreciated. I am already missing some prime driving weather here in KC.

[toplessexpat]

Dumb question - is the pump in the right way around?

[bradartigue]

Easy enough to test, remove the plugs and unplug the coil + lead (makes turning the engine easier on your starter and no coil = no spark) then run a fuel line from the input to a (full) gas can, another from the output to an (empty) gas can, and run the starter. If it transfers fuel from one to the other then plug the output end to the carburetor and try again. If it puts fuel in the carburetor then you are either connected to the fuel return (small pipe) instead of the fuel delivery (big pipe) or you have blockage. If it transferred fuel to the empty can but not into the carburetor then your float needle and seat aren't adjusted correctly or the screen in the carb is blocked, or something in the bowl is wonky.

[archiethe3rd]

I am only assuming (uh oh) that the pump operates as the old one did with the input line towards the rear of the car and the output towards the carb. Is it possible the new pump is the opposite of the old one? Brad I will try the test and that should tell me what's up. Thanks.

[toplessexpat]

There's usually an arrow that shows the direction of flow.

Also - make sure you've got it wired up the right way around.

Andy

[bradartigue]

There's usually an arrow that shows the direction of flow.

Also - make sure you've got it wired up the right way around.

Andy

78 = mechanical

There should be an arrow pointing IN <- on the thing but who knows with aftermarket parts. Usually the one closest the firewall is IN. Test to be sure.

[RoyBatty]

This is a reply I left in another similar thread.

I have recently changed out the mechanical pump on the 1600 in my Coupe, only to find the new pump would not move fuel.
I took the diaphragm from the new pump and installed it to the old pump and all worked great.
I believe the check valve assy in the top of the new pump was not working properly. If I recall the new pump was using a spring loaded reed valve for the inlet and outlet check valves and they just weren't doing the job.
The old pump used spring loaded balls in the check valves.
If your pumps have the same bolt pattern and physical appearance, this might be worth a try.

[toplessexpat]

Brad - good point ... I haven't had a mechanical pump for years and I'd (perhaps incorrectly) presumed people would replace them if they failed!

[archiethe3rd]

The pump is working opposite of how the original Italian pump worked. The "in" is furthest from the firewall and to carb points towards the rear of the car. I got plenty of fuel line now that I tested it. I will post again if this works and especially if it doesn't. Thanks gentlemen!

[archiethe3rd]

Fuel hoses switched and it's running great. Thanks everybody. What a thrill to drive again! Wish I had done that fuel pump test a year ago.

[toplessexpat]

Glad you're sorted - sometimes it's the simplest things!

A

[bradartigue]

Fuel hoses switched and it's running great. Thanks everybody. What a thrill to drive again! Wish I had done that fuel pump test a year ago.

Glad to see it is running. Do it a favor and drive the s**t out of it, they love it.

Alcohol is different at 36,000 - I typed this 6 times.

[toplessexpat]

Alcohol is different at 36,000 - I typed this 6 times.

Did it also make a LS1 powered spider seem appealing?

[bradartigue]

Alcohol is different at 36,000 - I typed this 6 times.

Did it also make a LS1 powered spider seem appealing?

Nope. I like my Spiders with the original engine. But I would love to put a Subaru boxer-4 in one if it would fit and I knew I could finish it. It probably would not and I would likely not finish it.

[toplessexpat]

Now - would an integrale fit?