TheSamba.com :: View topic - Ignition problems (when engine is warm) MSD 6AL

Mon Apr 14, 2008 4:49 pm

Alright, so I have an MSD 6AL that I recently installed on my 2017cc, and never had a problem with it. But last week I went to a local show, drove about 40-50 miles there and about 25 miles into the drive (mostly all around 75mph) I had to pass a semi, so I pressed on the gas and the car just hesitated, like it wasnt firing right, almost like the rev limiter was engagin right then and there.
I let it cool down for a few minutes (pulled off the highway) and it was back in business .... for 10 or so miles, when it started doing it again, it was so bad that 5 miles later I could not even maintain 50mph in 4th !
When I got home that night I checked every spark plug wires, all good, I replaced the coil wire (I use the Bosch kits) since it had the coil wire with carbon center, and I read those could go bad, so I put an old one I had with stainless steel center, I also put a new rotor and cap.
Drove to work a few times no problems (short distances)
Today I was driving to a place about 50 miles away, the first 30 miles are on the freeway, and of course after 20-25 miles it started doing it again, and by the time I pulled of the highway I could not even cruise at 50mph in 4th ! I pulled over in a McD's parking lot and 3-4 minutes later I was back on the road, MSD 6AL bypassed, no problems whatsoever. I drove all the way back home later with not a glitch .... so I am guessing the 6AL is to blame. It's got less than 1000 miles on it, and didn't do that before (not that I noticed at least)
Any ideas where to start looking ?

Mon Apr 14, 2008 4:50 pm

oh and it works fine, unless you drive for a while on the freeway ....

Mon Apr 14, 2008 4:58 pm

I had similar problems, they were fuel related... What does your fuel system consist of? Pump, regulator, lines, carbs, etc...

Mon Apr 14, 2008 5:15 pm

stock pump, weber 44IDF, fpr (set at 3lbs I think)
but I dont think its a fuel related problem, because as soon as I bypassed the MSD box it worked fine ...

Mon Apr 14, 2008 5:28 pm

Your problem is most likely your distributor rotor. I have the 6AL on my Ghia, and chased an intermittent spark for over a year. I finally learned the stock rotor has a resistor in it and the higher voltage of the 6AL, combined with the fact that it fires multiple times per cycle will start to burn out the resistor in a fairly short time. CB performance has what is called the Max Spark rotor - http://www.cbperformance.com/catalog.asp?ProductID=1253 - which uses a solid conductor. Once I installed that, it's been running great.

Mon Apr 14, 2008 6:31 pm

pantherman wrote: Your problem is most likely your distributor rotor. I have the 6AL on my Ghia, and chased an intermittent spark for over a year. I finally learned the stock rotor has a resistor in it and the higher voltage of the 6AL, combined with the fact that it fires multiple times per cycle will start to burn out the resistor in a fairly short time. CB performance has what is called the Max Spark rotor - http://www.cbperformance.com/catalog.asp?ProductID=1253 - which uses a solid conductor. Once I installed that, it's been running great.

funny you mention that, UPS just delivered my max spark rotors (I ordered 3) along with another new Bosch 009 distributor cap and a new Magnition rotor cap (http://www.cbperformance.com/catalog.asp?ProductID=340) just after my last reply, and I just came back from a quick 20 mile test drive and .... that didn't fix it.
I tried both the rotor and cap, just the cap, just the rotor, nothing worked (it only took about 12 miles to make it happen again, and it happens suddenly, one second it works fine, the next it wont go anywhere ...)
As soon as I went back to the 009 with pertronix (bypassed 6AL) it runs great :(

Tue Apr 15, 2008 12:09 am

Maybe your MSD is overheating, where is it located?

Tue Apr 15, 2008 12:56 am

i had the same problem with my MSD 6AL, and it is located under the rear window inside the car, so i don't think i had overheating issues, it happened late autumn here in sweden when it isn't warm outside at all.

It felt like i lost spark all together, just for a split second, it felt almost like the car stood on its nose, happened a couple of times when the engine had warmed up properly, after about 20min of highway driving. Really strange, checked all wires and plugs but found nothing.

Please post if you find out what the culprit is.

Tue Apr 15, 2008 6:47 am

miniman82 wrote: Maybe your MSD is overheating, where is it located?

It's under the backseat. I think that may be a possibility too. I'm going to get a MSD coil and see if that fixes it, if it doesn't I'm just going to ditch it ...
And Tobias, it does sound liek we have a similar problem

Tue Apr 15, 2008 8:12 am

Two other things to check... If you are using electronic points, be sure the screw holding them in place is still tight. It can loosen, the car will still run, but you get an intermittent grounding of the point case, resulting in missing. Also, the MSD wants spiral wound plug wires. If you are using carbon wires, they may be breaking down. They also don't recommend solid core wires, which will cause Electro Magnetic Interference. Hope this helps...

Tue Apr 15, 2008 8:25 am

pantherman wrote: Two other things to check... If you are using electronic points, be sure the screw holding them in place is still tight. It can loosen, the car will still run, but you get an intermittent grounding of the point case, resulting in missing. Also, the MSD wants spiral wound plug wires. If you are using carbon wires, they may be breaking down. They also don't recommend solid core wires, which will cause Electro Magnetic Interference. Hope this helps...

ok cool thanks, yes the electronic ignition is tight in there :)
As for the plug wires, I am using the Bosch ones, I think those are not solid core right (wound stainless steel) and the coil wire was a carbon center type but I found an older set I had that had the wound stainless steel center and put it on. The Bosch ones are not solid core right ?

Tue Apr 15, 2008 9:24 am

71sbeetle
do you have a rev limit module pluged in the 6AL, I had one go bad once. you don't need one in place for the unit to work. I have one under the hood of my Scout II and it gets very hot and never has a problem.

Casey

Tue Apr 15, 2008 9:34 am

earthquake wrote: 71sbeetle
do you have a rev limit module pluged in the 6AL, I had one go bad once. you don't need one in place for the unit to work. I have one under the hood of my Scout II and it gets very hot and never has a problem.

Casey

yep a 6000rpm module, removed it and it was still doing it, I tried another module, still does it.

Tue Apr 15, 2008 10:18 am

At this point, I'd suggest contacting MSD for help, or a warranty replacement. I see you are in West Palm Beach, so am I. Email me and maybe I can take a look at it and see if I see anything you might have missed.

Tue Apr 15, 2008 2:26 pm

I think I found the problem and now I feel so stupid !!!
I have a remote oil cooler with a fan, the fan has a thermostat that makes it come on at 180 degrees ..... the power for that fan ..... I used the power that went to the coil originaly ..... so basically just used one of the connectors on the positive side of the coil. When I had first installed the 6AL, the engine died as soon as I put it in reverse and I knew immediatly and exactly what had cause it. I disconnected the reverse light power wire from the coil and went on my merry way !
Later on, I just tapped directly into the power (that used to go to the coil positive and now goes to the MSD and Compufire red wires) and my reverse lights worked again. So I guess I will have to do that for my fan too :)
It's OK to use that power (switched on from ignition) to power things right ?
Thanks to all that helped !
Now I need to find a good spot for my oil cooler so I can fit my Kafer Bar ......

Tue Apr 15, 2008 2:50 pm

Sounds like accessories robbing power from the ignition box. I would put a relay in there if you're powering more than one thing off the switched ignition line.

Tue Apr 15, 2008 3:32 pm

miniman82 wrote: Sounds like accessories robbing power from the ignition box. I would put a relay in there if you're powering more than one thing off the switched ignition line.

well actually it works fine as long as it's not connected directly to the coil :)

Tue Apr 15, 2008 3:43 pm

Glad to see you figured it out. Electrical issues can drive you crazy! Are the main power and ground leads for the MSD conected directly to the battery? This is how it is recommended to be wired by MSD and will eliminate anything else drawing down the current for the MSD...

Tue Apr 15, 2008 4:02 pm

pantherman1952 wrote: Glad to see you figured it out. Electrical issues can drive you crazy! Are the main power and ground leads for the MSD conected directly to the battery? This is how it is recommended to be wired by MSD and will eliminate anything else drawing down the current for the MSD...

yep connected straight to the battery :)