'94 GT-40 Starting Problem

[lancask]

I have a '94 Sport Nautique with a PCM 5.8 Pro Boss EFI GT-40. Occasionally the engine will not fire at all ... and it seems to be after a long ride or session, after it sits for awhile. It just cranks over without firing. While this is happening, no smell of fuel. I pulled off the spark arrestor and no fuel jetting out of the four TBI fuel injectors. The second it starts to deliver fuel, it usually runs normally for the entire session. Low pressure pump engages on ignition key.

Do you think this (1) a fuel supply problem, (2) a fuel pump (low pressure or high pressure) problem, or (3) a command module problem?

Two other problems, related or not:
(a) The engine seems to run hotter than past seasons. I replaced the impeller with some improvement but still runs over 190 to 200 degrees.
(b) Occassionally experience a lack of power on full throttle starts with dark exhaust.

[peteSki]

I've got at 97 Ski with the same engine as yours. I had a similar problem in that she would always start and run fine for a while, then without any loss of power or sputtering would just die. Then I'd have to wait 4-5 minutes before she would start again. During that time, I could not hear the fuel pumps engage when the key was turned, the engine would crank, but never fire. After much diagnosis, my problem was entirely electrical. There are 2 wires connected to the positive terminal of the battery, one is huge which carries the current needed for the starter, and the other goes into the EFI to run the rest of the electrics. There is an inline fuse on this wire in the battery compartment. My fuse had become corroded to the point that it would heat up after a few minutes until its resistance would be so high that there was not enough juice to run the EFI... instant shut down. The 4-5 minutes I had to wait until the engine would start was the time needed for the fuse to cool down. During the time the EFI is offline there are no fuel pumps, no spark, no nothing, but the engine will crank. I suggest you inspect this fuse and wire, as it is an easy fix if it is indeed the problem.

During my problem I didn't notice any difference in engine temp nor a difference in exhaust fume colour, maybe your problem goes a bit deeper. At least it's a cheap place to start!

Hope this helps,

Pete