Most tanks have an anti siphon valve, after years of sitting it may be clogged. Other possibility is that the fuel lines themselves have degraded from sitting with ethanol fuel in them.. Try running the system on a portable tank to see if it draws fuel without problem. If it draws fuel we'll then the problem is in the tank end of the system, not your fuel pump end.
I've already checked and I have no problem getting fuel from the tanks. I'm definitely dealing with an issue past the new fuel pump, which I'm certain is siphoning fuel.
Do you have a low oil pressure fuel switch. My 26’ has one that stuck off on me the other day. It shuts the fuel pump off if there is under 5psi of oil pressure.
That's a good possibility. I'm not sure if I have one. Where did you find yours and how did you solve that issue?
I know mercruisers have two pumps. A low pressure supply pump and a high pressure pump for the fuel injection.
My suspicions were correct. Found the culprit. Going to order a new one this week and hopefully I'll be one step closer to firing it up next week.
Well, I installed the new one and am getting good pressure to the TBI. Still no start though. Got a couple squirts from one of the injectors but overall still not really getting them to fire consistently. I'm thinking at this point I need to remove and rebuild the TBI, probably have a clog somewhere from sitting? What do you guys think? It's really the final thing I haven't replaced in the fuel system.
Are you certain they are supposed to be firing? Do you have spark? Are the batteries turning it over fast enough for it the TBI to sense starting?
What is your voltage reading at the injector heads when cranking? It should be above 9 volts to spray. IIRC, there is a screen in the injector bodies which may be clogged from sitting. But first make sure you're getting adequate voltage from the ECM.
