another egine miss
 

Went to St. Louis for national open and car missed all weekend. Had just put a 280 in it I purchased, and car has never had a miss before. The computer showed it, so not in our head. Steve changed plugs, and wires. Could it be the crank trigger? Just need to know where to start. Have not had it out since. Ran one decent 1\8 mile time, but literally falls to pieces on big end. And it's not the springs, the tach jumps around when it misses.

Re: another egine miss
 

Check your ground cables and the negative post on the battery

Re: another egine miss
 

Thanks, I will.

Re: another egine miss
 

Un-plug the tach also. Swap out the battery disconnect.

Re: another egine miss
 

Nice thing is you have a datalogger so you can rule out a few things, such as voltage issues as would be with a bad disconnect switch. Since it would seem you simply swapped engines (assuming you're using the same coil and ignition box tach ect.) I would start with engine grounds, crank trigger air gap, or simply swap out sensor. The polarity getting crossed on the crank sensor could be a cause as it would change your timing. Hopefully you have access to an MSD ignition tester, the first thing I would do is hook it up and run the system up thru it's range, this will let you know that the box and coil are up to the task. On the datalogger does it also show the RPM bouincing around also? Sounds more like you're having a triggering issue than anything. Hence using the MSD tester. Joe

Re: another egine miss
 

which tester is used with a MSD 7AL-2 not a plus but a #7220 MSD box???

Re: another egine miss
 

The 8996 will work on all of them that I'm aware of, they do have another not sure of the part number that's more geared toward the Digital boxes. I believe it will test the cam sync signal also. Joe

Re: another egine miss
 

Joe -thanx will look into it

Re: another egine miss
 

Ya, rpm drops. Have a mallory in it, but do have an msd tester. Will it work? Also, same coil as was in other engine, but everything else is the same.

Re: another egine miss
 

I changed motors in my Corvette once and had the same problems. Turned out that the main battery cable nut on the starter lug had not been tightened. All power for the vehicle, ign, etc came off of that terminal. Tightened the nut on the lug and fixed the problem.