No Start. 4.3L Gen+

[Fleetwin]

2003 (I believe) 4.3L Gen+ (2 barrel). Serial #: 0M047305

Engine cranks fine-No Start.

Yesterday, I replaced:

1. Spark Plugs: A/C Delco
2. Plug wire set MerCruiser
3. Dist. Cap MerCruiser
4. Rotor: MerCruiser
5. Fuel/Water separating filter: MerCruiser

All the parts were identical to those replaced.

I did such a great job that it no longer runs! :facepalm: It started fine, ran great, after all the parts were replaced and ran for 30-45 seconds then died. Never restarted. Cranks fine with a good strong battery..

I have verified I have fuel to the carburetor. Although flow seems very weak while cranking. The only issue I ran into changing the fuel filter is that the fuel filter housing nipple came out with the filter element. I had to re thread it into the housing and then spin on the fuel filter.

I checked spark with a spark checker. In my opinion, it is weak and erratic.

Questions:

1. What did I do?
2. Best place to find/buy OEM diagnostic manual.

Thanks.

 

[Fed]

Could it be sucking air through the nipple?
Maybe fill the carby manually and see if you get another start & short run?

 

[Fleetwin]

I was thinking my next step is to bypass the filter assembly for testing only. I've got to figure out how without destroying something. Thanks.

 

[Bonus Check]

Shot of starting fluid. If it starts then you have a fuel problem

 

[Fun Times]

Did you fill the fuel filter with new gas before installation? It helps a lot.

Have a timing light? if so, connect the timing light inductive pickup sensor to the coil wire and watch to make sure the flash is very consistent...Then check a few plug wires as well during cranking.

Is the Tachometer moving up to around 300 RPM during cranking.

The shift interrupter switch may have moved out of place just a bit so be sure the switch trigger is centered in the V....Rock the shifter handle a few times too.

Make sure the main wiring harness cannon plug connector didn't get bumped while working on the engine...Wiggle the wire harness plug around while cranking.

Next may be using a test at the coil and following the tips of this school instructor to make testing the ignition components a bit easier, https://www.youtube.com/watch?v=jJmqdhhduVc

 

[Fleetwin]

Did you fill the fuel filter with new gas before installation? It helps a lot. I DID.


Have a timing light? if so, connect the timing light inductive pickup sensor to the coil wire and watch to make sure the flash is very consistent...Then check a few plug wires as well during cranking. I do not but have inductive tach.

Is the Tachometer moving up to around 300 RPM during cranking. Did not notice.

The shift interrupter switch may have moved out of place just a bit so be sure the switch trigger is centered in the V....Rock the shifter handle a few times too. Will Check

Make sure the main wiring harness cannon plug connector didn't get bumped while working on the engine...Wiggle the wire harness plug around while cranking. Will do.

Next may be using a test at the coil and following the tips of this school instructor to make testing the ignition components a bit easier, https://www.youtube.com/watch?v=jJmqdhhduVc

Will Do.

 

[Bonus Check]

Check the Lanyard Kill Switch

 

[Fleetwin]

Update:

Folk s.

I think I figured it out. It's fuel.

As remembered/suggested, I sprayed r some live fuel in the carburetor.

We have ignition, No lift off= yet. At least I know I have igntion.

I "hotwired" the fuel pump. It runs but sounds a bit sick.

I'm ordering a fuel pump. My rationale is I think the crud in the fuel system made it fail.

 

[Volphin]

Glad it failed in the driveway instead of on the water! Your new boat must really like you!

 

[wahlejim]

Did you coat the o-ring on the fuel filter with oil before installing it? Did the old o-ring come out when you took the old filter out? You could be sucking air in from the filter.

 

[Bondo]

Did you coat the o-ring on the fuel filter with oil before installing it? Did the old o-ring come out when you took the old filter out? You could be sucking air in from the filter.

Ayuh,..... 'n What was in the fuel filter ya took off,..??

Water, 'n crud, or just gasoline,..??

Did ya prefill the new one at all,..?? oilin' the o-ring is a good point too,....

Hook up a remote fuel can, directly to the fuel filter, 'n see if the fuel pump, pumps better,.....
Pull the line off the carb, slip a hose over it, point it into a catchcan, 'n jumper the pump,... Good Flow,..??

If the fuel tank ain't willin' to give up it's load, the fuel pump, may not be the problem,....

Diagnose, 'n Then order parts,.....