440 loss of power

[72 fishbone]

ok to start out I have a 1972 barracuda with a 440 engine it has a big mutha thumper cam 1.6 harland sharp roller rockers. 10:1 compression. I am running the MSD atomic efi setup with the MSD fuel pressure return system and high hp output fuel pump 625hp MSD blaster coil Taylor 409 Spiro pro race wires. I had a pro billet distributor from 440 source. car ran perfect had lots of pickup no sudden stalls great response time. I did 2 pulls on a Dyno first pull 450 hp adjusted timing car was running slightly rich second pull 487 hp both pulls at 6000 rpm. went to check the springs in the 440 source distributor and noticed that one spring would travel 1/4 in before activating so we changed it out with better springs but when we went to install the distributor and start for the next round we noticed it wouldn't start after investigating we discovered that the rotor was not turning spring tension was good but car wouldn't start. after hours of back and fourth trips to the auto parts store we ran out of time so we decided to overnight a new pro billet MSD distributor. placed new distributor in car. car fires up no problem but now I have no power hell I cant even get over 60 mph before it strats breaking up. we ohmmed all the wires they were good with no burn marks replaced all plugs, plugs gapped at 40 and old plugs were good not fouled, conducted compression test, re checked timing all shows good but I have no power. can anyone please help on this matter before we start to tear into the engine? could it be an electrical issue?

 

[Adam]

Sounds like you are not getting any advance. Check total timing at 2500 rpm. It should be around 34 degrees btc, and not climb further.. then hook up dist vacuum, if you have it.

 

[Daves69]

IMO, R & R of a distributor in a good running engine does not translate to something mechanical to me. Has to be something you did, changed, or overlooked. I'd go back to where I was before the fiasco.
Pictures and settings documented prior to any change made would be useful here I think.

 

[Chryco Psycho]

Do you know why the rotor quit turning ?
I would say it is elecrical not mech also

 

[Steve340]

If your cam is a roller are you running a compatible distributor drive gear?
Test it with known good carb if you can. That eliminates all the MSD stuff.
Have you checked fuel pressure?

 

[Cazbah362]

To me this sounds like a timing and or MSD box issue. Is there a rev limiter in it? Doesn't it synchronize with the Efi? And 34 is low to me for all in, 37 to 39 is what I have Harv best luck at.

If not, what is the O2 reading? Did the efi re-calibrate with new distributor? Those are my initial 2 cents

 

[Cazbah362]

And since you removed distributor - did you discover why the rotor was not turning? Damage to gears?