mike tkach

iTrader: (3)

black smoke does not always indicate a fuel problem.a weak ignition that can,t ignite the fuel could be the issue.

SB

iTrader: (1)

I agree Mike. Famous one is people using standard reach plugs plugs (MR43T's and MR43TS's) in a Vortec head, which takes a longer reach plug. (MR43LTS)

1 2 NV

that wouldnt account for the over fueling though right?

SB

iTrader: (1)

You can use a vacuum pump like a mityvac or equivalent.

1 2 NV

well its been awhile since i did any troubleshooting. the FP reads 42psi while the engine is running. i was too busy to check the FP when the boat was going down the river as it was extemely rough and the wife was tending to the little guy who was scared of the river conditions. the only thing to note right now is by the time i got home the FP was almost to 0. it bleeds fuel pressure off slowly.
so at this point im guessing its the MAP sensor.

1 2 NV

one other thing that came up. someone ran their identical engine to mine with a diacom on it. until it heated up to 165 he was burning 9.8 gal hr according to the diacom. after it reached that temp the fuel usage went down significantly to 8.3 gal hr. most people i know burn 7-8 gal an hr with a 350.
somebody also mentioned it might be the temp sensor. ill have to get a different meter to read the resistance in it.

Trash

The reduction in fuel use as the motor is warmed up is normal. There is a table in the MEFI 1 that modifies the Base Pulse Width (BPW, fuel injector time on) vs Engine Coolant Temp (ECT). It is effectively an electronic choke. Richer during cold ECT conditions, leaner while at operating temps.

1 2 NV

i wish this thing would get figured out. i havent been using the boat much so its my fault. its a pain to haul it to the river so i can test any idea that might come up.

so ive read through the troubleshooting manuals quite a bit. to set timing it says you need the DLC tool. im betting that the DLC jumpers 1 connectors together to set base timing. does anyone know which wires need jumpered? i dont have a DLC.

Trash

The DLC is simply the Data Link Connector located near the MEFI 1. You can jumper the A / B ports to get the ECM into base timing mode. You can do this with a paper clip.

Start the motor, bring the rpm up just a little (1000-1200), jumper the A / B pin outs on the DLC connector and you will be in base timing mode. Put a timing light on the balancer and adjust the distributor until you get 8 deg BTDC. Lock down the distributor and remove the DLC jumper. Base timing is now set.

The motor may run goofy or rough during base timing mode. Don't freak out, this is normal. It may stall when you remove the jumper. That's ok too. Simply key off and restart.

That's the Cliff notes version. Others may chime in if I've forgotten something.

1 2 NV

thats excellent info trash. thanks for that info. im planning on hitting the river in the next week or 2 and will certainly time the motor.