Ok my Grabber has some popping at 2500 rpm and above, has had the Holley 750 on it and the 650 also, same results with both carbs, BUT when I was in the shop reving it up I noticed something strange, I noticed some arcing in an unusual spot, the bolt with the spacer that holds on the altenator, it was arcing between the alt. and the spacer! it was only doing that at the higher rpm's, now yes I do have the chassis and engine both grounded with straps, also noticed my tachometer quitting at the same time the engine is popping, at the higher RPM's. My Mopar buddy thinks I have a grounding problem, what are your thoughts?
I suspect that your arcing is not from your charging system, but from your secondary ignition system. 12V will not arc very far at all. Do you have any plug/coil wires near there? Does the engine misfire get worse if you sprits your coil and plug wires with water?
I have it unhooked at this time Frank, was doing some accessory wiring. No plug wires or the like close by, wires are new as of Sunday but had this issue before the install of those, I can check the water thing tomorrow.
There is likely dirt/corrosion between spacer and alt causing a poor ground when RPMs are up... Most orig alts have fair balance at best, so tend to vibrate a bit at higher speeds...
I'm not sure if it will work without the ground, but yes the alternator should be grounded. I run a strap from mine down to my block where the battery cable is grounded to it. I can't quite recall if the original alternator had a place to ground to... If not I would be looking to drill and tap somewhere on the case to screw in a bolt and a small ground strap.
To add, sometimes you need to remove it and clean the mounting surfaces to bright metal. I have had this happen before! The powdery aluminum corrosion will prevent a good connection. And yes, as was mentioned, the alternator must be grounded to work properly!
Ok so it was the Alt. hunting for a ground, cleaned up mounting bolt and spacer ends along with where it contacts the head, no more arcing.....but tonight I went out and started it up just to be sure and I could see the spark in about the first inch of my new plug wires nearest the dizzy cap! I guess that could be from the dish soap residue that may still be on it from boot assembly.
Ok Frank, let me see if I can explain, on Sunday I put new Taylor wires on my engine, they were cut to fit and assemble, I had trouble getting the boots on the wire so I used Dawn dish soap to help the wire slide in the boots easier, I wiped all I could of the dish soap off, last night I went out and started it to see if I fixed the arcing issue with the alt., at the dizzy cap, for about the first inch of wire coming out of the boots I put on, I could see sparks in a few of the wires traveling inside the wire, in just a few of them and only right at the boots for about an inch or so.
I'm pretty sure that is a bad thing. You should let everything dry and check it out again. Also relying on the bolt and spacer ground is insuficient, run a 10-8 awg wire as an aux chassis ground is all you need.
Run it from the alt. casing? And yes today might be the day I get another carb. and a Pertronix dizzy, getting fed up with the Duraspark and old Holleys I have been using.
