my rx7 doesnt want to start...its a 1984 gsl with a 12a rebuild less than 200 miles,mild-ported exhaust.weber dcoe...it rode fine till one day that it just shut off on me... i took out the fuel line from the carburator and installed a hose leading to a 2liter coke bottle with gas and it ran perfect...i checked the fuel pump and it was fine but bought a new one anyways,the fuel tank was fine no garbage of any kind,checked all the lines,then i got a new fuel pump relay thinking i wasnt getting any power, but still nothing...any suggestions???...(and yes i have searched and researched but still nothing)...

 

new fuel filter?

 

yeah that was changed as well...not once but twice

 

how do you know its a fuel issue?

 

beacuse when i took the fuel line out and put my own hose leading to a 2liter coke bottle tied down to my winshield it ran perfectly fine...so that means im not getting any fuel to my carburator..

 

Try the coke bottle just before the pump, if that works, then the filter or the pickup in the tank is pluging.

 

what do you mean try it before the pump?

 

coke bottle --> fuel pump---> carburetor

 

basically, use the coke bottle as the gas tank. remove the lines to the tank and use the 2ltr instead.

 

yeah thats what i did and it worked perfectly fine

 

Rymon and I had this issue on a Bridgeport with webers..
His fuel pump was a jegs one, but it would lose its prime or something at idle.

To solve it, we upped the pressure on the fuel pump to like 8 psi and put in a restrictor that let roughly 2 psi drain back through the stock return line. The gas is always flowing, the carb gets its 6 psi, and it hasn't stalled out once since we did this.

I assume pumps need to keep flowing gas or they lose their prime or vapor lock or.. whatever the hell you call it.

Hope this helps!

-Edit-
As another note, our origional thought was maybe the mounting of the fuel pump was causing the issue, as it had to be higher than stock. However, ever since the restrictior, the problem has never showed itself, so the mounting must be fine.

 

yes i will put that in consideration thank you very much gekitotsu,jeezus,and trochoid...please keep coming with suggestions though just in case that theres another problem that we havent covered...this aint my computer and my computer doesnt let me make threads or reply

 

any more suggestions on what the problem may be?

 

[QUOTE=mr.12a]i took out the fuel line from the carburator and installed a hose leading to a 2liter coke bottle with gas and it ran perfect...i checked the fuel pump and it was fine but bought a new one anyways,the fuel tank was fine no garbage of any kind,checked all the lines,then i got a new fuel pump relay thinking i wasnt getting any power, but still nothing...


^^^^^^ seems to me your fuel pump is fine according to you. So is it working or not? Your statement tells me that your fuel pump is working. In a later statement you say it is the fuel pump. Here you say the pump is fine.
Did you check to see if you have any gas coming out the squirters in the carb when you throttle it? Check the float bowl and see if you have any gas in there. Check for spark?

 

I've never had this problem, but it sounds like the pickup may be plugged. Is it possible to blow a little air backward thru the pickup after detaching from the pump? I think it's probably a bad idea to add air pressure to the fuel plumbing ordinarily, for fear of blowing a diaphragm or something, but maybe it's OK if the pickup is isolated.

 

Blowing air back into the tank may help is there is a restriction. Be sure to remove the gas cap 1st. If that doesn't help, then check your fuel lines from the tank to the pump, both hard and soft. There is a short metal fuel line between the tank and the pump, bolted to the back of the bin wall. I had had one that had a tiny pinhole leak from rust, couldn't see it until I removed the line. Drove me nuts until I found it.

 

ok thank you i guess im going to check all the lines again...hopefully thats the problem

 

What am I missing here? He tested the fuel flow and it checked out fine, right? It was asked before, but why are you sure that it's a fuel delivery issue?

 

because it runs fine when i do the coke bottle thing its like if i made my own fuel pump...but when i take off the coke bottle and put the fuel line in for the fuel pump to the car it doesnt start..

 

Maybe I'm not understanding how you performed the flow test? You should remove the line at the carb, and place that into a bottle, then run the pump to test the flow rate. Did you do it some other way? You said you taped the bottle to your windshield, so it sounded like you did it this way...

 

no but i am going to try that tomorow...the coke bottle has a hose in it and the other end of the hose was connected to the carburator,the coke bottle had gas in it,so its like if the coke bottle was my fuel pump..

 

So the coke bottle was used as your fuel tank? The fuel pump worked fine? But when you hooked it back up to the fuel tank of the car it didn't flow? If that's the case then it can be the fuel line (kinked, clogged somewhere) or the tank itself.

 

yes sir that is correct,but thats what i dont understand when i inhale into the hose of the fuel pump of the car gas starts coming out ,so thats why i thought the fuel pump of the car was bad so i got another one....and nothing, so then i thought i was getting no power to the fuel pump i changed the fuel pump relay, but still nothing....

 

Can you hear the fuel pump running at all when you turn the ignition on? Do you have spark on the trailing side? I've learned that the trailing side igniter of the distributor gives the fuel pump its'power. Check the fuse for the fuel pump? Just throwing out some suggestions.

 

no i cant hear it when its on the on position.im going to go check the fuse again...