MSD Install, now no power
 

It was the last thing to do. Been working on this engine for almost 2 years. I have fixed/replaced everything. The last piece of the puzzle was the PermaTune and original coil.

After replacing with new MSD and high vibration Blaster coil (from our host) the car now drives like there is a banana in the tailpipe.

I double checked the timing @ 950 rpm and vacuum disconnected to be 5 BTDC. Then I put the vacuum back on and set the idle back to 950 with the AF ratio running around 14.2 to 14.3 (as read on the LM-1).

Power is limited and it just feels like there is a restriction in the exhaust. I made sure the Freq Valve is pumping away as that not working is similar to the feeling the car has now.

I am out of ideas to check.

Please help!

Dave,

Two things,......

1) Did you maintain correct phasing on the coaxial trigger wire coming from the distributor?

2) What is your total timing @ 6K?

3) If its the MSD 6AL, did you snip the red wire for the 6-cylinder rev limiter?

Msd
 

Reverse hook-up of the wires coming out of distributer with two coming from MSD box. Correct polarity is the one that gives you the greatest retarded timing.

Hi Steve,

Thanks for the comments.

1. Yes, trigger wire polarity is correct. I actually swapped this just to be sure.

2. Timing at 6k is 24 degrees with all vacuum disconnected.

3. Not the L version just the 6A, so I don't have the rev limiter.

The car drives, it is just anemic. I have spark, fuel, and timing is OK. I am frustrated and just don't know what to do at this point. Put the PermaTune back in to see what is going on? I don't think that is a good solution.

One thing I did notice that may be a clue. The timing (5 BTDC) is not rock steady. It varies a tiny amount and you can see it wiggle. Make a difference?

Thanks,
-Dave

didn't see the second response from e p slick before my 2nd post. When I tested the trigger wire polarity, I could not find the timing mark with my light. I had to assume that as one of the polarity selections got me right at the normal timing and one of them was so out of phase I could not find the timing mark that it wasn't too hard to figure out which was right. Am I thinking correctly?

Is it possible to wire the coil up backwards and for the car to run at all? I can tell it is something so simple, but I can't put my finger on it.

As crazy as this sounds, I too had a similar situation. I installed the MSD 6A ignition, 100% correctly. However my plugs were not updated at the time since they were newer.

I purchased a set of 8ES bosch or NGK can't remember and regapped them and BOOM fixed my slow car problem. If i recall correctly they were 2 points higher in heat and the gap was rather large.

my symptoms where exactly as you described and all it took was replacing the plugs and fixing the gap.

JW

at the same time I did the plugs I also re-checked the timing so I am 100% sure it was a combination of the 2. I'm not too sure why the plugs reacted they way they did to the MSD but it did.

Cool. Thanks JW

I will try some other plugs. The ones in there are new but standard Bosch super copper for the SC. Is the 8ES a hotter plug then standard?

I regapped the existing plugs to 0.045". Maybe I will try a smaller gap with these while waiting to get the hotter plugs.

I really appreciate your input.

-Dave

Getting the right plugs / gap with the MSD is important. I don't have the specs in front of me right now, but it's different than stock. Also, what you're describing sounds really like it's running on less than six cylinders. Check each wire with a timing lamp, and check the temperature out of each exhaust pipe (you can put your hand on each one when you first start it). Ones that are not running properly will be cold...

-Wayne

Thanks Wayne.

I will check to see if they are all firing.

How do I know which plugs to try next? Should I get an assortment?

I guess it is time to do a search to get an understanding of plugs.

-Dave

Another question I forgot to ask.

Plug wires. I replaced the shielded stock with the pre SC non shielded Beru (early stock) wires. The MSD says not to use solid core plug wires. What do I have with the Beru stock wires? Should I use something different?

TIA
-Dave

Personally I would use the shielded wires, again here is exactly what I did when I had the same problems that you are experiencing.

Plug was a standard Bosch / NGK B8ES
Shielded wires Factory between .040-.050 gap on the plugs.

I would use the factory wires re-gap and double check your firing order Just in case. Double check your MSD connections . Do you know anything about the wires you are using?

If you used new plugs pull out each plug 1 by 1 and look for one that hasn't been firing if that is the case. It should be pretty obvious.

I am sure it is something very simple.

Jon W.

Thanks Jon W.

The plugs and wires are all new. Less than a few hundred miles on them. I had the problem right out of the chute with this MSD change so I pulled all of the plugs and re-gapped them from 0.028 to 0.045. They all looked about the same, pretty clean but with some white residue on all.

No change to how it ran after changing the gaps. The plugs are Bosch WR-5-DC+ whatever that means.

sounds like you have a plug wires in the wrong spots. The engine will run and maybe smooth but power will drop off

Dave,

I am assuming the car is an SC. My symptoms before were:

1. At start, the engine ran and idled fine.
2. Pulling out of the garage, it was somewhat fine.
3. At first gear, it was somewhat fine.
4. At acceleration, it was bucking.


Turned out that I had installed the wires backwards.

Hope that your issue is similar to my mistake.

Good luck.

Again I would retrace your steps :

- Check Plug wires and firing order , it's easy to do if you took them all off.
- Check and double check the MSD wiring, grounds
- Were the old Plug wires working - Re-install those
- Could you have turned or rotated the dizzy in any way? Unlikely but it can happen
- You could try a hotter plug you are using a 5 I dont know the new spark plug numbers off hand but mabey get a hotter plug like a 6 or 7?
- Lastly I purchased an MSD that was faulty right from the get-go they did replace it but don't rule that out. They have been known to be bad right out of the box rare but it happens.

If all the plugs are firing well you have spark in all 6 cylinders, sounds like wrong firing order.

At least you know its a relatively simple issue, just take a break for the evening and hit it fresh in the morning, sometimes an overnight break helps you think more clearly. Just a thought.

Good luck and let us know what you find out, but Put the stock wires back on though!!!


JW

You probably messed up the plug wire locations. Don't feel bad, I have done this many, many times, even after checking twice. It's very, very easy to mess this up. Check it 3 times.

-Wayne

Ok. It looks like the last 4 responses are all the same: "incorrect/backwards firing order"

I hope all 4 are correct!!! :)

OK. Here is the update.

Quadruple checked all the plug wires. Everything A-OK.

Pulled out the MSD/Fuse panel assemble to make sure I had all connections underneath back together. Pulled apart the connections at the old CDI 6-pin connector for the trigger and moved them to the side with some silicone tape to insulate. (I wasn't sure they had a good connection inside the connector). Rewired the orange and black wires from the MSD directly to the coil instead of through the 6-pin. General wiring clean-up.

Got it running and used the timing light to see if all cylinders were running. They were, but I noticed that while pulling on some of the wires, the idle changed a bit. Hmmm.

So, I started re-seating all the plug wires. when I got to the #2 connector on the distributor, I could hear arcing while I wiggled it. So I pushed in on it and got a nice shock. Shut down the engine. Pulled the cap and reset the #2 wire using one of the old insulators from the original shielded wire set. Put it all back together and went for a drive.

Whoo Hoo! No more banana in the tail pipe! It doesn't pull as hard as I would like though. I feel there is more to get from it so I will seek out the hotter plugs and give that a try.

Thanks to all for the help.

-Dave (Grinning from ear to ear)