Gt40 No Start... Except at First

[Emil]

So I posted about my boat in another thread, starting this one because it's not really about injectors anymore. Anyway my 2000 super air only starts about once, then when I try to take it out, it won't start again. I did have a bad battery replaced, and I thought that would fix my issue, and it seems like it kind of does. I'm really not sure, but every time I let my boat sit on the trickle charger, then start it, it fires almost perfectly it seems. I know both batteries are good, I have now replaced my MAF, TFI, cap, rotor, ECM and fuel relays, TPS, injectors, high pressure fuel pump, fuel pressure regulator, and PCV on the block. I have no idea what else it could be other than ECM, spark plugs, Profile Ignition Pickup, or ignition coil. I have a new ignition coil coming thursday, and I think I'll try replacing spark plugs tomorrow. Has anyone seen this be an issue somewhere I'm missing? Like the keypad or some secret breaker? I've tried the breakers on the engine and they don't seem like they're tripped. Honestly, I'm all for any wild theories, after I've replaced my plugs and coil, I'm seriously considering swallowing my pride and taking this to a shop. I just don't understand how it could start and run perfectly fine one minute, then not a minute later.

[FMSKI]

You say you replaced the ECM, then say "other than the ECM"?

Test for fuel pressure, and that it stays >30PSI. There is a schrader valve on the distribution rail.
There is also a component that pulls off the circuit board of the ECM due to vibration. There is a youtube video by cluengineer that shows this issue.


You know I've rarely seen issues with spark plugs or relays in my lifetime. Although plugs can help performance on certain engines.

[Emil]

When I said “ecm and fuel relays” I meant ecm relay and fuel pump relay, I haven’t replaced my ecm. I do have good fuel pressure, I’ve tested it dozens of times, stays pegged at 40, only dips a little when starting. Anyway, I was doing more work tonight AND THE PLOT THICKENED, I turned the batteries on and had no power to my dash, couldn’t use the keypad on either side. I’m now very optimistic that my PME is bad under the dash, because I have a perfect 12.8 volts to it, but obviously no power out of it since my keypads don’t do anything. Of course when I say optimistic I mean I’m optimistic that I’ve located the issue, I’m not ecstatic about replacing the $800 PME. Gonna test the PME output tomorrow.

Also, I will look into that ecm issue you mentioned if my PME turns out to be fine.

[Emil]

Just to resolve this thread, the issue with the dash power, I can't explain. The no-start problem, however, was fixed by re-timing the engine. I have no clue how it became out of time while driving, but it's fixed now.