LTR trouble ( no spark )

[DaleR]

First time user,..bare with me. I just purchased a 1999 prostar 205 with a LTR 330hp engine( 3 wks. ) I've had a 99 205 with a TBI for 4yrs. Was planning on selling and keeping the LTR.....however....The LTR eng. and boat has only 60hrs on it....the block was cracked/ heads/ exhaust manifold...total rebuild and ready to go....nope....
I assumed the boat ran before it was froze up so was hoping for an easy fix. As it turns out I have no spark and injectors are not firing....full of fuel..kill switch is working, I get initial fuel pressure and guage clusters working....after cranking for several seconds I get oil pressure...I've checked all connections, grounds, batt. post.etc. etc. more than once...3 fuses on back of eng. are o.k.....checked connection at fuel pump. Could it be something simple? Any ideas? Thanks.

[JimN]

If you did the engine swap yourself, the crank sensors could be in the wrong position. Switch the lower one with the upper one- they fit in either but if they're wrong, the ECM thinks the motor is turning backward and won't fire.

[Engine Nut]

JimN is right. The two wires that go to the crank sensors are not logically sized. You would think the longest wire would go the the sensor that is farthest away, but that is not the case. Try swapping the leads and I bet your engine starts.

Engine Nut

[DaleR]

Thanks for replying so quickly guys! Had all ready tried the crank sensor swaps...However brings me to the next question! When I rebuilt the engine the only ( small??? ) detail I couldn't remember ( memory was better 20 yrs ago ) was that the crank pulser ( behind harmonic balancer ) had 2 key slots 180% from ea. other.Was 90% sure??? Assumed ( you no what that means ) I would still get spark. Could it be ??

[Engine Nut]

I went out and looked at the trigger wheels we have in stock. They only have one keyway in them so I am not exactly sure what you have. Dis you check the voltage output of the crank sensors? They should produce between .8and 1.4 volts at cranking speed.

Engine Nut

[JimN]

There's also the possibility of a bad IC module or ground, too.

[DaleR]

Engine Nut/JimN wish I could buy you a BEER! Your initial suspicions were correct. You kept mentioning the crankshaft sensors ( backwards..no out put ) When I checked the voltage ( .8-1.4 ) I had none on both sensors?? Then I noticed the AIR GAP, excessive!!! Adjusted as close as possible. fired up rightaway! DUMB!DUMB!DUMB! Sorry about that. I'm sure glad your out there! I appreciated the help/education immensely. Thanks, Crazy Canuck.