4.3 GXi-A Won't Start

[Davidmccallum]

Engine is a 4.3 GXi-A Model Number is 3869114.
Problem started when the exhaust tube for the riser to 90 degree down pipe blew. This sprayed salt water all over the engine causing the cap to crack and the coil to stop working. I replaced the cap, rotor and coil. The engine started right up. I shut it down and started cleaning up. After washing down the deck I opened the hatch and water pored down all over the alternator. The alternator shorted out and caught fire. I put the fire out got another alternator installed and now the engine won't start. I checked the 3 fuses by the 50 amp breaker and the fuses and breaker all have power going to and from them. I checked for spark at the coil and that seems good. I checked for fuel and the injectors are spraying fuel when I crank the engine. The engine cranks fine and seems like it wants to start at first but then just cranks.

My question/s,
Are there any additional fuses that I could check?
What is some other steps I can do to diagnose the problem?

I am very mechanically able but I have not worked on fuel injected boats or cars so the extra wires are new to me.

Thanks,
David

 

[Fun Times]

Re: 4.3 GXi-A Won't Start

Hi there, Wow you're having some bad luck. Hope it turns around for you soon.

By chance, do you think any water got in past the flame arrestor wetting down the spark plugs? May want to pull he plugs to confirm.

Have you tried opening the throttle about a 1/4 to 1/2 way while cranking? Just thinking may be the IAC valve went out and usually opening the throttle will be a bypass test.

Just be aware that the crank position sensors and if your engine model utilizes the camshaft sensor under the distributor cap, they both are sensitive to short circuits and electrical spikes.

While cranking, does your RPM gauge move to around 350 RPM?

Do you hear your fuel pumps turn on at key up and while cranking?

Hopefully you didn't short out any circuits within the ECM, though highly unlikely, it can't just be ruled out either.

There are some fuse on the engine along with some relays. They may be in a black type fuse box mounted on the engine.

Let us know, Good luck.

 

[dearborndeuce]

Re: 4.3 GXi-A Won't Start

I have a new 200HP SX only 50 hrs on it.
First sign of ambient moist air ( start of our rainy season ) & no way it would start.
Took it to my installing VP Dealer who indicated this is a common prob ( no-start ).
Suspected coil pk & installed a new one. Eng fired instantly.

Then the VP dealer owner suggested to re-install the old coil pan just to chk again.

End result determined to be a bad ground on the coil pk.

In my case the damp air most likely worsened the grnd connection to the mount plate of the coil pk.

Just chk all you grounds very carefully including you battery connections.
they have to be stainless nuts on the battery ( no wing nuts )

Good luck.

 

[Davidmccallum]

Re: 4.3 GXi-A Won't Start

Thanks for the replies,

Fun Times- I changed the plugs today and tried the throttle. Got some back firing but no start. The RPMs are going up to around 300 and the fuel pumps are turning on. I haven't tried the crank or cam sensors yet but I am going to research them to see what they should be reading and doing so I will know how to test them. I changed the ECM with my other engine so I know that is good. Also checked all the fuses in the black box and the 50 amp breaker and all are good.

dearborndeuce- I changed the coil and checked the grounds. I'm going to pull everything off again this weekend to double check the grounds.

My next step is to swap parts from my running engine one at a time till I find the problem. I'm also going to check the timing and plug wires. The back fire makes me think timing is off or some issue with distributer.