[TexasZ212]

Originally Posted by Chris B

It was the ECM. Did not take to dealer did all the trouble shooting myself in the boat lift, was about 99% sure it was the ECM after all the testing. Ordered new one, changed out and it fired up. I learned a lot doing this myself and now know why dealer charges so much to work on one of these. Perfromed some other task while working on the engine, like change out the belt and re-wire the 12V batteries and system the PO had this thing tuned into an electricians night mare. Few things left to do as the isolater is bad and the on board battery charger is not working, will change them this week. Other wise all is working fine and boat is running great (knock on wood).

Liked what you said about "learned a lot doing this myself". It sure helps a bunch to know how and what to do when things don't operate or perform as they should. One can never know when you will be in a bind to repair/diagnose something...that's when that previous experience is priceless. Helps out with your wallet too.

And thanks a bunch for coming back and posting what the solution to the problem turned out to be, so we can all learn from it.
So many times on forums there is massive discussion about problems, but then the original poster doesn't ever come back to say what particular thing turned out to be the problem and what was done to take care of it. We don't learn all we could have from those threads. Just kinda leaves us all scratching our heads and wondering what the problem turned out to be.

[Hudson River Steve]

Chris,
Congrats on finally solving the problem. It's great that you stuck with it and the knowledge that you gained will only help you in the future.
Happy Boating
Steve

[mikeyt]

Originally Posted by TexasZ212

Liked what you said about "learned a lot doing this myself". It sure helps a bunch to know how and what to do when things don't operate or perform as they should. One can never know when you will be in a bind to repair/diagnose something...that's when that previous experience is priceless. Helps out with your wallet too.

And thanks a bunch for coming back and posting what the solution to the problem turned out to be, so we can all learn from it.
So many times on forums there is massive discussion about problems, but then the original poster doesn't ever come back to say what particular thing turned out to be the problem and what was done to take care of it. We don't learn all we could have from those threads. Just kinda leaves us all scratching our heads and wondering what the problem turned out to be.

X2 !

[Roger Butterfield]

Folks I thought I'd continue on with this thread in that I have a 7.4L MPI, Z280, and my situation is somewhat similar in that the engine turns just fine but won't fire. After I let it sit for a week or so I try it and the engine actually fires for about 3 seconds and quits. I'm getting spark from the coil to the cap so the plugs should be firing. I have a clear fuel line and the fuel filter is not clogged, dirty or obstructed. I have turned the key on and off a few times to cycle the pump and still nothing. I took the breather off the throttle body and sprayed starting fluid in several times but still nothing.

What have I missed?

Thanks

[Chris B]

When you turn the ignition switch to on position does the warning buzzer sound? Also have you checked the fuel pump relay, it is on top of the engine just in front of the distributor. There are 2 grey colored relays side by side, looking at them the right or front one is the fuel pump relay the left or rear one (depending how they are positioned) is the spark relay. They should both click when you turn on the ignition switch. If fuel pump relay does not click on and run the fuel pump for about 3 seconds and the spark relay clicks, switch the 2 relays around and turn on the ignition. If the fuel pump relay clicks when in the spark socket the relay is good. If the spark relay in the fuel pump socket does not turn on the fuel pump for about 3 seconds you have to do more trouble shooting. Let me know what happens.

[Roger Butterfield]

Hi Chris:

Yes, the buzzer does come on when I turn the key to the on position. I will definitely check out the relay switches as you described - thank you!

[DCB_MINDED]

You checked fire from the coil to the cap, but did you check fire coming through the cap? Rotor could be cracked or bad. Did you replace the plugs & wires and possibly get the wires mixed up? check timing, compression?

[Roger Butterfield]

Yes, I tested three or four of the wires on the cap by pulling and seeing if a nice spark displayed once the engine turned and yes, nice spark on each one. Did not replace the wires and plugs so they are all in the correct position. I haven't been able to check the two relays in front yet so hopefully those will prove to be the problem.

Thanks for your input

[Roger Butterfield]

O.k, I gave the engine another try and it did start, however, it felt and sounded as though it were running on 5 cylinders, couldn't keep an idle and smoked like crazy. Awhile back, before the problem of not being able to start the engine, I was out and about when my overheating alarm sounded. Got it towed, replaced the impeller, which was chewed up, checked misc openings and ended up replacing the risers since they appeared blocked. So I have two problems now; 1), very rough engine that smokes and 2), overheating.

Ideas?

[rayzorback]

Just had my impeller replaced as it was also shot. The mechanic also found some pieces of rubber in a coolant line on the opposite side of the motor (Not sure where). he said many people don't check there for impeller parts and can cause blockage which in turn causes overheating. Hope that helps.