D37 Plug has Fried

[The Panel Van Man]

Hello from Down Under to all. I hope someone can help me. I have a MS 2 which worked fine with the stim. The idea was to run 16 LPG injectors on a 351 Cleveland. [2 banks of 8]. When we tried to run the engine the D37 plug fried where the driver wires go through it. There are no shorts anywhere and every thing is wired correctly [been checked more than once]. The wires are not burnt just the plug and the end of the board. The injectors are 1.5 ohm resistance. I have ordered a new MS 2 as the damage looks too great to fix and I do not want a repeat happening. The reason for LPG injection is I am chasing a LPG Land Speed Record on a salt lake in Australia.

[Matt Cramer]

What did you have PWM current limiting set to? If the current limiting is off, you'd be trying to feed ~160 amps of current through four pins rated at 5 amps each. To hold these to a 1 amp hold current (per injector) would need a 10% PWM current limiting amount, which would put you within safe limits. These may need an external peak and hold board, like the JBPerf one.

[The Panel Van Man]

Thanks for the reply Matt. Yes the current limit was set to on. The guy who built the MS 2 for me thinks that it would be a good idea to build a driver board with only two injectors per transistor. He's the computer geek, I build engines, does this sound like a good option. He is able to do this he says. I think I have come up with a way to duel stage the injectors using the output from a shift light to operate a relay and power up the second set of eight. So start on two banks of 4 and at 3500RPM switch to
two banks of eight [Two per cylinder]. Thanks Alan TPVM.

[trakkies]

MS seems happy with 4 low impedance injectors per driver - after all it comes from the land of the V8. ;-)