when did this start ? seems if you ran a std HEI and still did it with no electronics it had to be a issure with the timing chain/cam ?? you have isolated it I would think...keep us posted..Rob

Are the plug wires well seperated? Could be crossfire between two wires.
Did you try the timing light on #6 as well?

I'm going a few years back,my neighbor had a similar problem with his twin turbo twin spark alfa romeo that he raced on the salt flats..the timing was all over the board with multiple timing spikes...it turned out that the engine builder used the wrong type of noise suppression wires,we changed them to the mds wires and all the timing issues went away..i think the builder used copper core wires and msd ignitions don't like those style wires..

We use spark plug wire shielding on all the plug wires on our drag cars..seems to help cross fire and with al the voltage the msd digital 7 puts out its a must

Rob, this is a new engine, on the test stand, was headed for the dyno before this showed up.. Happened the first time I fired the motor and since then..

Plug wires are MSD Super.. 8.5's.. Using 4 sets of seperators, the good MSD ones..

Keep them coming.. I know it is something dumb..

Thanks
Dick

do you know anybody close that you can borrow a digital 7 box and coil from ? just to try....those boxes handle the timing differently..just a thought...Rob...ps the coil has to go with the box..it's different

I talked to Dick today. Seems he has the problem fixed. I am sure he will post what he found.

As Vinny said, I did some testing. I seperated the EFI and MSD by using two diferent pickups.. The MSD on the crank trigger and the EFI on the pickup in the MSD dist. Ran the MSD 6AL on a seperate battery.. and it still did it..
That's when I broke out the new set of MSD wires (Super 8.5's). When I fired the motor, the timing did not jump!! I didnt believe it, so I ran it for a few minutes and the timing was rock solid. I could rev it and not see the timing move or jump the 90*.
I then connected my EFI to the MSD 6AL and ran it for about 25 more minutes. I did see some misses and not so stable timing, but I never saw it jump 90* like it did consistently before. I will now be able to look at the EFI and make modifications until I get it working properly.
I will be doing more testing tomorrow, to verify that I have found the problem.
The previous wires are probably 3-5yrs old. I had shortened them for use on this new motor, seeing that my old motor was a 11.6" deck, all the wires could be shortened. I also had 4 sets of MSD seperators on the wires to make sure there is even spacing and no wires touching each other. I am not sure if I put the ends on improperly (which I had originally installed when they were new) or if the insulation had broken down. I did clean them with mineral spirits..
But, I do know that after I fired the motor with the new wires (which do not have all the seperators on them and are touching each other in spots) I have not seen it jump the 90* since.
Tomorrow I may connect the crank trigger directly to the 6A and fire the motor and open a few beers and watch it run with two or three of the timing lights I have now! (gotta love ebay for old timing lights)..
I will let you know what I find tomorrow.. And I want to thank Pat from Tech West Racing.. he helped me work through the problem with his vast knowledge and experience. I will be sending him my 6AL next week for modifications and rebuild. After I get it back, he will get my spare 6A.

I also want to thank everyone for all the ideas and offers of equipment loans and help.. Sure is nice to have OSO and great people willing to help.!!!

Dick

glad you got it !!! had a weird problem with my race car for a whole season with ignitions....which after battling for months simpley traced to B/S chinese made marnetic pick-ups in both MSD and mallory dist. basiclly they do not hold up anymore(cheap crap) and tend to crack and until they finally fail hard to figure out when you have brand new ones that are junk out of the box !!! crank trigger seems to be the only real fix !!! Rob

Mr. G - Please PM me Pat @ Tech West Racing contact info. I have a few MSD boxes I'd like checked out. Thank you.