are a fairly cut and dry installation right? Well then why am I not getting fuel to my carb? Background...converted from fuel injection back to a Holley carb. Removed the over plate from the fuel pump location and the pushrod was still there. So I Installed a OEM type mechanical pump. Fired up the engine and it held steady at 4psi until you revved it up and then it would drop to nothing.. OK...so I purchased a Holley 80gph mech pump and installed it thinking it would put an end to my dilema. Nope... still no fuel. Not even getting to my pressure gage. What am I missing?

 

Could the cam lobe that drives the pump pushrod be flattened? Or is there a tank venting problem?

 

Most engines have a bolt in the front, perpendicular to the pump push rod. Check to be sure it isn't screwed in tight and not letting the rod move.
The bolt is used to hold the pushrod in place while installing a pump, then must be loosened so it will move.

 

Venting does not seem to be the problem. I removed the gas cap just in case and still nothing. And I can push the rod in with my finger about 1/2 to 1 inch so I dont believe the bolt is holding it . Interesting about the possibility of a flattened lobe. Because the car does have a different cam and it did have a electric fuel pump(when it was fuel injected) . I would still use a electric pump but there dosent seem to be anywhere to mount one near the gas tank. The one that was installed before was up front towards the passenger wheelwell. Very risky spot IMOP

 

Just for yuks, I reinstalled the electric fuel pump. And now i`m lead to believe there was no problem with the mech pump setup at all. When I start the car up, the fuel pressure gauge shows about 10lbs of pressure(I didnt install a reg cause I`m just testing the system) and then drops down to about 3-4lbs and dropping. Does not stall out. It seems as though I have a problem between the tank and the fuel pump. Any thoughts? Maybe the line is pinched somewhere?

 

Trash in tank??

 

Boy I hope not. But it is a thought

 

Check any rubber hoses in the fuel lines. If there are any sharp bends, look to see that the hoses is not pinched.

 

If you are using one of those liquid filled fuel pressure gauges inline, do yourself a flavor and chuck it in the garbage, they don't read right after it is running for a while and heats up.

 

Two things: There is gas in the tank, right? (I don't want to insult your intelligence or be a smart a**....Stranger things have happened!)
Maybe your rubber fuel line is collapsing on itself when the suction from the pump increases. Good Luck!

temvette72

 

Cracked line may also be sucking air.

 

sock in fuel sender is full of junk

 

Sock just got replaced......could still be full of junk though. Thanks for the imput.

 

Sorry to keep beating a dead horse but this thing has got me twisted up in knots. Heres where I`m at. Removed the sending unit from the fuel tank and took a good hard look at it. No cracks in the line or debri on the sock. 3/4 of fuel in the tank(agrees with the gauge.) Replaced the old steel line with a 3/8 inch rubber fuel line all the way north to the electric fuel pump. So far so good. Started her up and the fuel pressure gauge showed 5 1/2 lbs of pressure going into my carb. Let it warm up a bit and it dropped a few lbs to about 3-4 lbs. Took it for a drive ran well. Parked and had another look at the gauge. it was back down to 1lb or so. But not stalling. This leads to what Motorhead was saying about liquid filled gauges being crap. Ok advice heeded. Hooked my fuel line back up to the machanical pump and nothing, nadda, no fuel. I suppose the rod pushing the pump is too short. Must have been cut. So then you ask ...why not keep the electric pump? would love too. But the placement of said pump is not in the best location as far as safety goes(just behind the passenger wheelwell on the inside of the frame). What I dont understand is why I`m not maintaining 5-6lbs of pressure. I did not check to see if the sock was bottoming out and bending causing a pinched situation in the tank.
Please help

 

I don't make this stuff up, if I told you to throw it in the garbage I didn't see it on TV or read about it, it happened to me, with one of the most expensive ones too

Sound like your electric pump is working, your mechanical is not working and to make things worse your gauge is not reading correctly.

Find out why the mech pump isn't working, start by taking the rod out and inspecting it and seeing if it the correct part for your motor

 

LOL I believe you ...only makes scense.. reads fine when cold reads bs when hot. I dont have a problem leaving the electric pumpin as well. I just dont like the location. A pump should push ...not pull. Thanks Motorhead.
.

 

One thing I just thought of. Had a guy working on my car who told me the sock on the sending unit had collasped. He put a new one on. But he couldnt remove the sending unit from the car. This am I removed the sending unit to inspect it. The sock was on there but it was black in color and I mean pitch black. arn`t they white when new? Hmmmm. I going to remove the sending unit again and put a new sock on. I get the feeling he didnt do what he said he did