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Discussion Starter · #1 ·
I posted this in the electical tech section also, sorry, but i need some help.

OK here goes.... all of a sudden i have a 500 rpm difference in between what i am programming my footbrake rpm in my digital 7 (program at 4000rpm) and when it is actually happening ( hitting footbrake rev at 3500 rpm). So what gives?

I have changed the dig 7, the coil, checked rotor phasing, checked timing, checked gap on crank trigger sensor, etc.... i am running shielded cable on the sensor.


I have changed the footbrake rpm either up or down and the problem remains a constant 500 rpm difference.

Could the crank trigger sensor be bad or going bad??


I have now noticed that my reluctor keeps moving after i set it to the magnetic pick up.


PLEASE HELP

-Mikie
 

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I had the same issue. The signal from FAST to MSD was picking up interference for some reason. DO NOT just raise the 2 step. If it's off 500 rpm down low, it will be off 1000 rpm at 6000 and then headgaskets go bye-bye. I fought this for 3 months.

The fix for me was to install another pick-up just for the MSD, that is if your currently running an FI box and MSD is picking up it's signal from the FI box.

MSD 7531 controls my timing via it's own crank sensor and map sensor, FAST controls the fueling. This is very common if you start looking around.
 

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Discussion Starter · #7 ·
Funny you say that about the dist gear. Thats what i was wondering last night.

Would a worn dist gear cause this??
 

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2 years ago on drag week the Hubers had a issue with RPM and it turned out the dizzy gear had worn a few thousandths, replaced it and fixed the gremlin they were chasing. Similar issue you are having, hell we about re wired the damn car haha
 

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Discussion Starter · #9 ·
WOW, thanks for the info. I have been speculating about that. I have a new gear coming.

Re-wire the car------hell that's about the only thing we haven't done yet....all though we have tried a BS3 and then back to the Fast.

If i do figure out what it is i will share with everyone.
 

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Discussion Starter · #10 ·
Well we found the problem................and it did end up being the Dist Gear.

Thanks to all for their input!
 
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