New Mechanical F.P.-no pressure

[jonsonton]

I just replaced my old mechanical fuel pump on my '87 Z28-305 4bbl because of low volume/pressure. I upgraded to a Mallory high volume fuel pump, now I get no fuel pressure. I've switched lines. What else should I check for?

[ct91rs]

did you match them up to make sure the rod/lever's are the same?

[jonsonton]

Yeah, they are the same.

[wrightz28]

Where are you checking for pressure?

[89IROC&RS]

installing the mechanical fuel pump can be tricky, youhave to preload the lever on the pump to install it with pressure from the pump rod. otherwise the rod is on the wrong side of the lever and it never operates the pump, causing a no pressure situation.

[jonsonton]

Just so I get the basics:

1. The pump rod is operated by the cam-Does the cam have a lobe specifically for the fuel pump, and if so is it egg shaped?

2. I felt a rod after removal of my pump-it doesn't even feel like it would come out far enough to contact the fuel pump lever. Am I overlooking something, or did I screw something up?

[jonsonton]

Sorry I didn't answer your questuion WRIGHTZ28-I had the fuel outlet line completely off and checked for fuel coming out.

[wrightz28]

the pump lever is under the drive lobe?

hmmm.

I honestly suggest pulling the pump off again and makeing sure you'r making contact with the drive lobe, I don't think you are.

[jonsonton]

The drive lobe? Do you mean the lobe on the cam? If so, I know the pump rod is contacting it, but I'm not sure about the pump lever. I'll check.

[89IROC&RS]

yes there is an egg shaped lobe on the camshaft dedicated to driving the fuel pump, it pushes on that rod not unlike a pushrod and actuates the lever on the fuel pump. the lever on the fuel pump should be very hard to move by hand, if it flops freely back and forth the pump is bad, and would not keep tention on the rod and would not be functioning.