Ran the car for the first time yesterday. Good news and bad news: Good: I got it through tech and the car launches straight and drives straight. Bad: it appears the MSD Digital-6 Plus is junk. It's the only part of the ignition system that isn't new. First run the engine would not rev past 3200. Second run we changed the plugs and it went to 3400. Third run we raised the rev limiter from 6000 to 8000 and it reved to 4500, but quit when it went into 2d gear for about 40 feet, then re-fired. Fourth run we raised the rev limiter to the max and it still only would rev to 4500 under load. And, it lost power when it went into third gear. Would rev to over 6000 parked. Also blew a rear seal on the C-4. So, we loaded up and went home sunburned and with our tail between our legs. The best run (4th) was 14.50 at 100 mph. So, time for a new ignition box. The Digital-6 Plus has already been back to MSD once, so I'm done with it. What are you guys running? I'm thinking MSD 6AL, but am open to other options. I only need one rev limiter since I can't run a two-step in Sportsman bracket.
Never had a problem with a 6al and using and adjustable rev limiter so no need for chips. Glad you got it to the strip but sorry you had problems the answer is more money as usual. 100 mph is good for a 14.50 run so you know it has potential when you get the rev problem fixed look for 12s high 11s
a friend of mine had trouble with his...MSD Digital-6 ...sent it back twice. I was there when he reinstaled it and it was still busting up. I noticed the ground wire to the frame was loose, he had a plug on the box end... he tightened it and all was well...
I'm going to recheck all the grounds tomorrow. They are all new. I completely rewired the car and used new battery cable for the engine to body/frame ground. All cable ends are soldered on and everything is grounded to both the body and the cage that is welded in. But, I will recheck everything again.
Hate to say it but MSD quality has taken a hit due to the typical outsourcing for higher profit that so many companies are doing these days. I myself have been lucky so far never having bought a bad unit but am still hoping my new programmable 6al won't be a dud when I finally hook it up. I think the odds are still in our favor from a numbers standpoint.. but it's still hit or miss from what I've read and seen on some of the local cars running around by me.
What kind of coil are you using? I was having a similar issue that I thought was the 6AL2 box, but it ended up being a weak coil. Now, with that being said, I've had a couple of buddies at the track who have had enough issues with the Digital 6 that they went back to the 6AL. I'd swap out a good box to verify before sending it in, but I'd be careful running it as well. Mine detonated bad enough to lift a couple of ring lands. These guys are supposed to be very good with MSD repairs... http://techwest.ipower.com/index.html If you have doubts about the MSD techs. I haven't talked to anyone who has sent anything in since Holley bought MSD, so I'm not sure if it's gotten any better or not. Good luck on it...
I'm using a new MSD Blaster coil. I don't suspect it, but who knows. I'll check it tomorrow also. I had a MSD 6A go bad on my Nova about 15 years ago. Sent it back to them and it's been running well since then. That's the only experience I've had with them. I've always used a Pertronix unit and coil on all my street cars and trucks. In any case, a 6AL is on the way.
If that does not fix it,try a 1 wire HEI dizzy,heck,for a $100 bucks it would be worth it.Not as much spark but a simpler set up.
Doesn't MSD recommend running the + and - directly to the battery? I know it was that way with the old boxes.
The 3 boxes I've had in the last 8 years have. I've seen all sorts of wiring layouts, many done for convenience sake, but if you really think about it.. why would you want to risk voltage drops and interference from another device sharing it's power and grounds, right? Which is why I'd guess MSD would expect the same dedicated power and ground wires on the newer boxes as well. They also want you to disconnect the box whenever welding on the car too.
I bought a clean power harness from Summit specifically to power my CD ignition and cooling fan. I did this primarily for troubleshooting purposes and to segregate these appliances from a 40 year old electrical chassis. If one is running an EFI/MPI setup, it is even more important. You see these type of harnesses on marine applications all the time, as trim pumps, bilge/live well pumps and hatch lifts can spike the ECU's, resulting in engine shutdowns, resets and other electrical gremlins.
I knew this was an issue with the old design 6AL boxes. Have not heard about any of the new stuff being copied.
I have a 6AL-2 for a back up box to my 7al-3. The 6al-2 has a lot to offer a drag racer. The 2 step limiter and adjustable limit switch. It's my chioce. P.S. My car had a mds digital6 plus. Operated without a flaw.
I have the digital programmable 6al2 and when we first installed it we couldnt get the car to run for crap if it even started. we had to go back and redo our grounds and then we had to set the initial timing before it would start and run. this is what happens when you dont read the instructions. even tech support wasnt budging from the ground wire issue when I called them. I thought I spent close to $600 for a reject. but after redoing the ground and setting the initial timing it started right up ran great weve played with the rev limiter on several different settings from 1500 to 4300 where its set at now
