MSD 6AL Question

[turtle5353]

Hey guys I am running a MSD 6al set up with MSD probillet dizzy. I was wondering if anyone ever had one go bad on them?? If so what were the symptoms if any?? Or do they just die and quit working.? I am asking because i took the car out over the weekend and it developed one hell of a miss. It will buck and cough/puke and shut off. hit the key and it fires right up but misses pretty much continually. I was hoping it was fuel related. Pump or bad gas. But im leaning toward the oldest component on my car which is the mds box. Im gonna start switching out some spare parts i have laying around to determine what it is. I have a spare coil. and a points dizzy somehwere i think. Also gonna go down and get the boat tank and electric fuel pump out of the derby car to see if it is fuel related. Its hard to say what it is because everything is pretty much brand new. Tank,lines,filter,carb all new. Plugs, wires, dizzy msd box and coil all new. Maybe water in gas?? I dont know just have to start eliminating this and chace it down.....Its either fuel or fire!! Just wasnt sure if a msd box would make it miss if it was going bad???

 

[caspianwendell]

I have never owned one myself but I sure have taken a lot of them off and thrown them in the trash for customers.

1. make sure nothing extra is connected to the coil (just the supplied wires from control box)

2. check ground to battery and positive to battery

3. check voltage on the switched wire to control box (what is the voltage)

4. disconnect coil wire from dist. and position half inch from ground, disconnect two wire plug from dist. and with ignition in the on position jump the wires from control box in short taps to check for spark through coil wire.

If all this fails MSD will rebuild the 6AL for you for 22 to 85 dollars plus shipping.

I personally like procomp or a modified dura spark II...they have served me well for years

 

[turtle5353]

Thanks for the help. It just started all of a sudden, but has been fine for 2 or 3 years that everything has been in there. Everything was new then.

 

[caspianwendell]

Thanks for the help. It just started all of a sudden, but has been fine for 2 or 3 years that everything has been in there. Everything was new then.

I know people who have had them for years with no problems and others that had nothing but problems. Sometimes they just go out but like I said I never owned one but I know how to diagnose them. Then again I like less wires and contraptions=less confusion and better reliability.

 

[turtle5353]

So would this cause it to miss like that or would it just die??

 

[caspianwendell]

So would this cause it to miss like that or would it just die??

low voltage from the switched wire, poor ground, rusted stater in the dist, cap, rotor, wires and defective control box will cause a miss but if it quits, it usually is the coil itself, coil wire, or control box. does it start to miss and then die as it heats up? if so change the coil

 

[c9zx]

Do this check. http://www.msdignition.com/page.aspx?id=3206

I've used them on several cars without problems over the last 20 years. Proper installation and matching components are required as it is with most things. Let us know what you find. Chuck

 

[turtle5353]

No it does it as soon as it starts. Shuts down but fires right back up. Seems like a fuel problem..... i hope. I will try and swap some things out this weekend and see what happens.

 

[caspianwendell]

No it does it as soon as it starts. Shuts down but fires right back up. Seems like a fuel problem..... i hope. I will try and swap some things out this weekend and see what happens.

That's a good possibility...follow the diagnostic link that c9zx posted and that will tell you. What fuel pump are you using and what is the preasure? I have been hearing tales of ethenol mixed fuel breaking down the older lines and clogging the filters but have not seen it for myself as of yet.

 

[turtle5353]

No it does it as soon as it starts. Shuts down but fires right back up. Seems like a fuel problem..... i hope. I will try and swap some things out this weekend and see what happens.

That's a good possibility...follow the diagnostic link that c9zx posted and that will tell you. What fuel pump are you using and what is the preasure? I have been hearing tales of ethenol mixed fuel breaking down the older lines and clogging the filters but have not seen it for myself as of yet.

I am running the stock fuel pump and the lines are all about 2 years old. All new tank, sending unit , lines , filter ,pump, and holley 700 carb.

 

[mikepasquale1]

Never had mine miss but when the battery was low it started missing and running rough whwn the electric fan kicked on. Charged the battery and tested the alernator. Everything tested good and determined with was the battery that was almost dead but was able to start the car with it. Im running msd digital 6a. I have seen an analog 6al go bad once on my buddies race car. He carries spares actually.

 

[Totalled]

I had an older box die just sitting undriven from one weekend to the next.

 

[turtle5353]

well im still hoping its fuel related. I was talking to a friend of mine that works at a local chevy dealership and he said they just had 3 cars come in to the shop in 2 days that wouldnt run. What they found was that the gas that they all 3 were just filled with contained 19% ethanol. The gas came from a local sheetz gas station. They are not allowed to put more than 10% in the gas. Sheetz was contacted about it and they are paying the dealership to repair all 3 cars. I dont know what the repairs consist of?? Drain tank and refill?? But I always fill my car up at that same sheetz. So im thinking I may have some shitty gas in the tank. Gonna hook up the boat tank and electric fuel pump this weekend and verify if it is the gas. If it is i will drain the tank and fill with some good stuff. Hopefully thats all the problems i have.

 

[c9zx]

The station is really named Sheetz? We could have a lot of fun with that.

 

[Tnfastbk]

The station is really named Sheetz? We could have a lot of fun with that.

Holy Sheetz bat man

 

[turtle5353]

Well I got the mustang running good again!!!! I checked the msd and coil and started checking fuel pump. All was good. I found that all it was, was BAD gas!! I bought a can of stp gas treatment and a can of 104 octane boost and let it idle in the drive for about 20 minutes. Took it for a ride up the road and it ran great not even one hicup! She is back to her tire smoking self again!!! Thanks for all the replies and help guys. Luckily it was an easy fix this time!!!

 

[c9zx]

Glad it worked out well. Think about not buying Sheetz gasoline.

 

[BigPinoyHunk]

i had a msd 6a go bad, but it did also sit doing nothing for 3 years near a beach.

 

[mustbrad]

I hate that sheetz