I am the only owner of the boat, motor is 2008 Penta GXi-J 4.3L I was living in SC at the time so lots of use/hours early on. In 2009 I preemptively performed the fuel pump module paint strip.
I moved back north and botched winterization in 2015 resulting in a cracked block. I replaced with reman short block along with new:
So, I checked fuel pressure - fuel rail was only showing 20psi with key on - Replaced both fuel pumps.
Now instead of no start, I had hard start - required half throttle to get going but seemed ok once it was running. This did seem temperature related and engine was now very rich/leaving soot all over the transom. So....
I Pulled cap, found some corrosion on pins though no real wear (not enough hours) so I simply cleaned/reinstalled. Miss was gone and I was confident I found all of the potential causes.
Everything seemed sorted and fixed- cold start it fired right up and settled into idle. Let it get up to temperature, shut it down, restart, same thing - perfect. Took it out to the lake, fired right up cold. Drove for 20 min, no stumbles/problems coming off idle/going full throttle etc... I stopped and anchored, still getting a ton of soot on the transom. Hung out for 90 min, went to fire up (essentially cold by now) and no start. Had to give part throttle.
I'm going to pull plugs, double check base timing. The only things left to replace are CKP/CMP/ignition module/coil. No warnings so I'm assuming manifold temp switches are good. Fresh premium fuel. The only thing I can think of that would command rich running that I've not replaced is apparently the ECM will enrich if it senses low battery voltage. Dash gauge and DMM showing 14v but the J1939 doesnt show battery voltage.
The scanner also does not show knock/advance/inject pulse width or anything else that might useful. It does show estimated gal/hr and that does seem elevated compared to charts I've seen online.
Anyone have a similar issue / ideas on a fix?
I moved back north and botched winterization in 2015 resulting in a cracked block. I replaced with reman short block along with new:
- flow matched injectors
- fuel filter
- cap/rotor/plugs/wires
- power steering cooler
- thermostat
So, I checked fuel pressure - fuel rail was only showing 20psi with key on - Replaced both fuel pumps.
Now instead of no start, I had hard start - required half throttle to get going but seemed ok once it was running. This did seem temperature related and engine was now very rich/leaving soot all over the transom. So....
- Probed/verified zero ohms between IAC/TPS/IAT/MAP connectors and ECM pins
- Verified thermostat with with DMM and thermometer/pot of water on stove
- Replaced IAC (it was a bit noisy with key-on / reconnecting battery)
- Removed/inspected/cleaned fuel pressure regulator, no change. Replaced with new, just in case.
- Pulled plugs... All were equally fouled with soot. Replaced
- Verified knock sensor function with DMM / rapping on manifold
- Verified TPS at idle/full throttle, scanned with a basic J1939 and there did seem to be a dead spot just off idle, Replaced
- Replaced IAT/MAP sensor
- Sudo verified CKP with digital timing light reading vs. reported rpm with J1939
I Pulled cap, found some corrosion on pins though no real wear (not enough hours) so I simply cleaned/reinstalled. Miss was gone and I was confident I found all of the potential causes.
Everything seemed sorted and fixed- cold start it fired right up and settled into idle. Let it get up to temperature, shut it down, restart, same thing - perfect. Took it out to the lake, fired right up cold. Drove for 20 min, no stumbles/problems coming off idle/going full throttle etc... I stopped and anchored, still getting a ton of soot on the transom. Hung out for 90 min, went to fire up (essentially cold by now) and no start. Had to give part throttle.
I'm going to pull plugs, double check base timing. The only things left to replace are CKP/CMP/ignition module/coil. No warnings so I'm assuming manifold temp switches are good. Fresh premium fuel. The only thing I can think of that would command rich running that I've not replaced is apparently the ECM will enrich if it senses low battery voltage. Dash gauge and DMM showing 14v but the J1939 doesnt show battery voltage.
The scanner also does not show knock/advance/inject pulse width or anything else that might useful. It does show estimated gal/hr and that does seem elevated compared to charts I've seen online.
Anyone have a similar issue / ideas on a fix?
