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Thread: Holley HP & MSD 7535 Startup issue.

  1. #1

    Default Holley HP & MSD 7535 Startup issue.

    I'm sorry for not searching much, but I have a quick question. I'm posting/asking this for a friend out in Oregon. He has switched from Big Stuff 3 to Holley HP EFI on all three of his Super Stock Cars. One engine is over at Barton's, and has yet to be put on the dyno and a program developed, so I gave him my program as the engines are similar. It will be good enough to get him to where we can start the car anyway. At least we thought. He duplicated all my stuff, except he has an MSD 7535, where I have an MSD Grid. He has all Hall-Effect, with a cam sync & sequential. Just like mine. When I switched mine over last summer, I had a heck of a time getting it running as the timing was swinging crazy. I called support, and they had me switching from Digital Rising to Digital Falling, among other things. Come to find out the Grid had 40° (default) Maximum Reference Timing and it was either adding, or subtracting 40° timing (to the Base Timing Table) based on whether it was rising or falling. Now, Sean is going through what seems to be the same thing, only he has the Digital 7 7535. Nowhere in the program for the MSD can he find such a setting. He's stumped, and I'm on the other side of the US. Any help would be appreciated. Jeff Niceswanger

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,661

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    It seems like the ECU is controlling the timing, and also the MSD Digital 7 CDI box. (Do you mean MSD 7531?) Ensure the MSD Digital 7 CDI box is programmed to not advance/retard the timing.

    Custom Ignition Parameters for MSD Flying Magnet 4x crank trigger & Holley 554-118 Crank Sensor:
    Ignition Type ............. ― "Custom"
    Crank Sensor Type ..... ― "1 Pulse/Fire" (← Holley 554-118 crank sensor LINK.)
    Sensor Type .............. ― "Digital Falling" (← Hall-Effect sensor.)
    Inductive Delay .......... ― "adjusted per application" (← Synchronization info.)
    Ignition Reference Angle ― "50° or 60°" (← Crank sensor setup LINK.)
    Cam Sensor Type ........ ― "Single Pulse" (← If sequentially injected or CNP ignition.)
    Sensor Type .............. ― "Digital Falling" (← Cam sensor setup LINK.)
    Output Setup Type ..... ― "Points Output" (← Loose white wire CDI box trigger.)
    Dwell Time ................ ― "2.0 msec" (← Do not set this to 1.5 msec!)
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  3. #3

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    Thanks Danny. Still having issues. All the settings you supplied are correct. Strange, it will run perfectly in static, but as soon as you put it back to normal, it jumps erratically. Jumps from 0 to 70 & back. Have tried two of my programs that run perfectly in my car, and it's the same with both. An of course it runs HORRIBLE. In static it runs prefect. Nice, Clean, Crisp with dead locked steady timing. Take it out of static and it runs just as you would expect @ 70 degrees out of time! BTW, the MSD is a 7535; the elite of that series.

    UPDATE: He tried everything yesterday Danny. New Holley unit, a different model Ignition (MSD 75301), new coil. Same identical thing. Still runs great in static, but non-operational if not left in static. Trying a new harness next. He is just about to put his Big Stuff 3 back in.

  4. #4

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    This is a weird symptom. Can you email me the tune from the ECU? I'd like to look over the settings and the advanced stuff that could affect timing after static is disabled. Also, what version & build level is he at? My email is rich(at)efiexpert.com

  5. #5

    Default

    Quote Originally Posted by fastmanefi View Post
    This is a weird symptom. Can you email me the tune from the ECU? I'd like to look over the settings and the advanced stuff that could affect timing after static is disabled. Also, what version & build level is he at? My email is rich(at)efiexpert.com
    Any news on this issue?

  6. #6

    Default

    He's awaiting a new front half harness that Robin Lawrence is supplying from Holley. Richard Nedbal from the forum found a few potential issues in the program, but after correcting, we still have the same symptoms. Sean is getting professional help elsewhere also, I'm not sure of who, but their racing friends out of Arizona. One thing that we did notice (that was different from mine) was Sean had his Racepak tied into the Holley and had never programmed the switch parameters in the Racepak. Mine is a separate stand-alone unit. It was too late to unplug and try it, as the harness was already out of the car waiting on the new one when we noticed it.

  7. #7

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    UPDATE: Changed the Digital 7 7535 to a new MSD Grid. This was after swapping out the 7535 for another box, I believe 75301. For some reason, the Holley does not like the Digital 7 boxes. After changing pretty much everything in the car, he now has a successful steady spark! It must have been some sort of issue between the Holley and the Digital 7s. Seems like he's on the road to success. One question. He is only getting 25° spark after setting the Crank Sensor at 50°, and his reference to 30°. It was at 5° and we moved the reference down to 30° (from 50°). That took the timing from 5° to 25°. So is it OK to just keep moving the Crank trigger to the commanded 34° at idle per map cell.? He couldn't try anything last night as machine work must be done to move it. For whatever reason, his MSD Crank trigger wheel is setting in different location than mine. Looks like maybe 5°. We noticed one of the four magnets is pointing right at 25°, where mine is at 30°. I didn't know MSD moved those around on series to series. Although, mine is lots older than his. We're certainly getting closer. Thanks guys.
    Last edited by Wanger 714; 03-14-2018 at 08:19 AM.

  8. #8
    Join Date
    Nov 2014
    Location
    Ont. Canada
    Posts
    648

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    Did you try flipping the crank trigger wheel over? That will put the trigger points in a different location.

  9. #9

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    Update: Running & close. Can someone post the link to change the plug on a MSD magnetic sensor. Trying to hook up the CAM sync and the factory Holley harness. The plug is going to have to be removed and the small MSD sensor is being installed on his front drive Jesel Distributor, but were not positive of the wiring. Thanks.

  10. #10
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    17,661

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    The Hall-Effect crank & cam sensors are wired as shown in the Holley EFI Wiring Manual:
    http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual - Figure 11/12, Page 20/21)
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

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