Promax?

[mercrazy]

Anybody used the eBay fuel pumps?

[skialot2]

As with anything from eBay, watch what you buy and who you buy it from.

[mercrazy]

What’s the chance of both these engines with melted piston having low fuel pressure? All injectors tested good. Ordered a pressure tester so I’ll see.

[Greg G]

Pressure meter is the next move, it is often process of elimination and never do two things at the same time.

[LakeFever]

Oil injection failure? Are the black boxes still on them?

[mercrazy]

Oil injection failure? Are the black boxes still on them?

No and no, never on my stuff since I’ve seen what can happen.

[mercrazy]

Fuel pressure is 34 lbs with engine not running. Could an old primer bulb be causing my problem? When I went to different vst/pump, it improved but still felt like it was running out of gas. After idling a minute, it would spin up on takeoff but start bogging after 300yards.

[Greg G]

Fuel pressure is 34 lbs with engine not running. Could an old primer bulb be causing my problem? When I went to different vst/pump, it improved but still felt like it was running out of gas. After idling a minute, it would spin up on takeoff but start bogging after 300yards.

Is the primer bulb holding a "really firm feel" when squeezed ? If it is, doubtful but a very simple fix

[LakeFever]

Good point on the bulb. Could be a poor seal somewhere along the pick up system. Check the tube in the tank too make sure all lines are fresh and tight. The pressure side will show as a leak but the vacuum side will be harder to spot

[Greg G]

Great grab Lake on the vacuum side

[mercrazy]

The bulb stays full but not hard. The tank was cleaned and pickup looked good. It picks up gas quickly when pumping the bulb. It’s a good omc bulb but 20 years old. I put a new pump in another vst but hate to change it if something else is wrong. Can these pumps make pressure and not have enough volume?

[LakeFever]

The lift side could be your issue. The vst tank would hold enough fuel to do what your describing but if the lift side doesn’t fill the vst tank fast enough? It’s going to fall flat on its face. So from the tank pick up to the vst would investigate all of that and probably replace all the rubber lines and take the pick up out of the tank to be sure it’s sound. The ones that are rigid plastic are usually durable and fine but sometimes they are nothing more than clear fuel line with a weighted screen on the end and I have had tanks with those that softened and became poor at picking up fuel

[XstreamVking]

Primer fuel exit must be pointing up for the check valve to work properly on most primer bulbs.

[KIRCHNER]

no mentio'n of the mechanical pump that feeds the vst? port side. pull off the feed line,squeeze the p. bulb....

[mercrazy]

Lift pump has brand new kit