This covers wiring of MSD 6a in all applications including installing it in a stock EFI system.
This covers wiring of MSD 6a in all applications including installing it in a stock EFI system.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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Got me? Have you traced the wires back to PCM? Wiring diagrams are here:
http://www.gearhead-efi.com/Fuel-Inj...rmation-EE-EEB
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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This is the current MSD config:Wiringdiagram.jpg
I could be reading/understanding this ALL WRONG, but here goes...... The MSD module would get abandoned. Using hybrid dizzy as you mentioned earlier in thread, the dizzy would be connected directly to ECM, and ECM to coil?
My head is beginning to hurt!
The ignition module gets connected to the ECM, to both trigger the ECM and allow the ECM to control timing. The igniton control module also triggers the MSD box. Look at the points trigger setup using the white wire.
The man who says something is impossible, is usually interrupted by the man doing it.
I gotta clarify this: when you are referring to "ignition control module" or "ignition module" are you referring to the module inside the distributor, arent you? This is all new terminology to me. I get it now. I've been getting that confused with the old school ford "brain module" (crappy square box with epoxy melted in the back) Old school Jeep wiring had only that ford module and the dizzy...thats about it. I replaced that "brain" with the MSD....
I'm still trying to clarify if using that hybrid dizzy is a good way to go. At first glance it an AWESOME WAY TO GO. Using that hybrid will allow me to connect it to the ECM, and so on and so on like you just described... I get it now.
I'M SORRY FOR THE seeminly dumb questions..... I've gotten lost in some of the terminology that I'm still getting used to.
Yes the ignition module he is talking about is the EST. It is the module inside the EFI small cap distributor. You can also use your MSD 6a box with it.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Originally Posted by jeepboy45
Ooo! Ooo! Pick me! Pick me!
Bosch ABS unit from Corvette!
Sorry... just blurted it out. :(
(Image shamelessly stolen from http://www.corvetteactioncenter.com/...abs/index.html
Last edited by 1project2many; 02-14-2012 at 05:37 AM.
Ok now I'm getting confused. Are yall saying he can use the MSD box instead of the 8 pin HEI module (for the op, thats the ignition module used with a the 16197427 pcm we are talking about, and many others) Or are yall saying he can continue to use the MSD box WITH the 8 pin module?
79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
He can use the MSD box with the 8 pin module.
The man who says something is impossible, is usually interrupted by the man doing it.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Thank you for for clearing that up. Strange though they had OptiSpark distributor, which I know had some slight mechanical differences. I'm wondering if the sensor wheel was the same? It seems to be key in determining which cylinder is firing as all eight are differant, so I wondered what the cam sensor was needed for. From your info I'm guessing no cam sensor on 92-93 either?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
Nope no cam sensor. 92-94 F-bodies had the non-vented opti. As near as I can figure mine came from a 94. I did modify my opti to vent it like the newer ones and the internals look to be the same as the later opti's. I have a spare b-body lt1 sitting on a stand in the garage and took it apart before I did the one in the truck just to get the hang of what needed to come apart. they are pretty similar excpet for the drive part on the back and the venting.
My research has shown just that. Early 1994 had the drive gear change but did not have the vent but was a dealer recall to do so. I have that paperwork with my car from dealer as it was upgraded to vented.
I also have one here taken apart, was told it can't be done! Ha! But then found the bearing is specail and no longer available. So buying a good aftermarket Opti with new bearing, using the stock sensor and wheel with new cap and rotor is still way cheaper than buying the entire unit new from GM. If I could have found a bearing it would have been a rebuildable part. Machining housing to new bearing would be more than buying one from like Chandler Motorsports who has 2 options, cheap one year warrenty, little more money for liftime warrenty. Lifetime warrenty has obvious better quality pickup sensor!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
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