MSD Power Grid Question

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by blowntrifive, Sep 4, 2018.

  1. blowntrifive

    blowntrifive Member

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    probably a asked a million time question but been having issues with the Grid on a Blown Alky deal BBC. Makes the 1 to 2 shift at 7500 and then after the shift hits like the Rev limiter and i cant go over 6500 RPMS been thru all my settings a hundred times. Does any one had this issue? Thanks
     
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  2. MaineAlkyFan

    MaineAlkyFan Active Member

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    Is this a brand new build or a recent upgrade to the Grid? What else changed? What does it sound/feel like after the shift? Is it rolling over or fighting itself?

    Chris Saulnier - Team Tigges
    Mechanic Falls, Maine
     
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  3. rb0804

    rb0804 Member

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    Recheck your safety setting in the grid and make sure that the rpm and times dont correspond with the area your having issues. Your using the grid with a mag or with an ignition box? What else is plugged into the grid (7761, etc)?
     
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  4. blowntrifive

    blowntrifive Member

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    Yes new build this year and first grid for me, it makes the shift and then sounds like hitting rev chip! look at the grid and you can see the shift light come on on the graph but not on in the car, but it shifts the car once.
     
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  5. blowntrifive

    blowntrifive Member

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    Correct a msd mag, nothing else on power grid except crank trigger etc
     
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  6. Critical Mass

    Critical Mass Member

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    In the Ignition Timing vs Engine RPM plot make sure that the engine rpm and the ignition timing point is what you want it to be at that rpm. This plot will prevent timing to advance if the rpm is not above the point set in the plot.
     
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  7. blowntrifive

    blowntrifive Member

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    Found the input signal was being dropped from the crank trigger to the grid. Now just have to find out why, bad pick up etc . Thanks everyone.
     

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  8. Mike Canter

    Mike Canter Top Dragster

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    Do you have a crossover switch for starting on the mag?
     
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  9. blowntrifive

    blowntrifive Member

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    Yes Mike I have a FIE Crossover switch from Spud that is also a kill switch. Thinking back when I first got this all done and turned over the engine ,every once and awhile the grid would show a crank signal fault but the car always started so I never thought about it till i ran the car and it broke up on the pass. Been doing so ever since. Now I know what is going on i can focus on getting it fixed and finding the problem.
    I never had a crank pick up just do this, it either works or it don't etc.
     
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  10. Mike Canter

    Mike Canter Top Dragster

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    Well Spuds switches are the best out there BUT that is what always failed for us and gave us the indications you have. One of the big causes of switch failure is from vibrations if it is hard mounted. We figured the contacts in the switch were vibrating so now I attach the switch to the straps on the front of the blower bag with a zip tie. So you are looking at the Ignition In waveform in the Grid internal data acquisition?
     
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  11. blowntrifive

    blowntrifive Member

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    Correct Mike Mine is drilled and tapped and mounted on the front engine plate next to the mag, I was cursing the grid at first but its not the grid , I ran a msd tested and all worked good and then it hit me about the crossover switch and the vibration, its been that way since I've run the car. its hard mounted to the plate and I'm thinking about removing it all together as I never needed it before it starts great on the trigger and always did, I liked the shut down features on this is why I bought it and installed it. Since day one it has had a miss fire on every pass passed the .330 .A friend should me the graph and blew it up on the screen and there it was, i thought it was hitting the rev limilter but it was never close to it, I really like the grid just need to find out what cause the trigger signal to go out on every run, I called and left a message for Spud and I will go threw all my wiring again to make sure its not a loose connection but Im pretty anal about that. Did yours look like mine and drop fire on the runs as well? thanks Vinnie
     
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    Last edited: Sep 5, 2018
  12. Mike Canter

    Mike Canter Top Dragster

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    Yes it did and it was mounted to the front plate. If it starts ok on the trigger then you should get rid of it. Shutting off powerto the Grid shuts down the motor
     
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  13. blowntrifive

    blowntrifive Member

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    I agree Mike thanks, Was it a FIE crossover switch? thanks again!
     
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  14. Mike Canter

    Mike Canter Top Dragster

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    Tried both the MSD one and the Electrimotion one
     
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  15. HootersFunnyCar

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    I've seen a crank trigger drop out at higher loaded RPM. Would do the burn out fine but drop out after 6000 once you swapped feet. Sounded terrible and you could see it on the graph.
     
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  16. blowntrifive

    blowntrifive Member

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    That is exactly what Mine is doing, burn out fine and then hits 7500 makes the shift and then miss fires and the input crank signal is lost , it did drop before the shift as well but mostly after 1.7 in the run. it was the pick up?
     
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  17. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    have you tried running it on the mag trigger through the grid?
     
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  18. blowntrifive

    blowntrifive Member

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    I have run the car in the pits on the mag trigger but never made a pass that way, thought about doing so at the race but wanted to make sure phasing was good before I did and ran out of time, I know if it worked it would of eliminated all the other stuff. Just removed and wired the trigger direct to the grid and got rid of wiring and the crossover switch last night, I like the grid but have heard so many stories of electrical issues I'm paranoid now. I know its a computer now and nothing like my six shooter was and you have to be really careful of the RFI and wiring I'm hoping that is my issues, did check run out on the trigger wheel and its about .020 out. Weird as you cant move it on the balancer anyway it centers itself I have .050 gap and it fires great on the trigger so I think I'm good. Thanks Will Always loved this site professionals here all the time, Vince
     
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    Last edited: Sep 7, 2018
  19. HootersFunnyCar

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    Bring a spare trigger along so you can change it at the race.
     
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  20. Mike Canter

    Mike Canter Top Dragster

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    The Grid is very reliable. I have been using them on cars since they first came out and have never had a failure. Most failures are caused by something outside the Grid but blamed on the Grid.
     
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