Been through all the threads here and other places. Even read the Tosto Racing thread at the MSD board.

I have a 408 24 tooth engine. Its very hard to crank. It starts intermittently. It usually will start with a jump vehicle or a full charge battery. However it has to spin way more than any engine I have ever had.

I am aware of the cranking speed problem and have ordered the MSD starter (second starter as they sell two of them) 50952 is the high speed starter 5096 is a regular speed starter and IMO isn't much better than the stock starter.

I just replaced the battery with a 1000 cranking amp MTP interstate battery.

Other guys here have had issues firing off then they say their engines loosened up or sync'ed and were easy to start after that. This isn't my case, mine is hard to start every time. After running it is questionable whether it will restart, every time. It has to spin like crazy to crank, every time.

It does not show cranking speed while cranking the engine over. After it starts it shows revs perfectly.


It's rev limiter sounds like a shotgun going off. unlike my previous engine that would just stutter. It also hits it very early compared to what its set at. AKA... rev limiter goes off before 7000 and its set at 7500

I have changed out the crank sensor and it does the same thing.
Any idea if the crank sensor needs to be a certain distance from the crank?
I know its not hitting the crank, but I wonder if being to close could be a problem? I know this distance is pretty much fixed into the block and getting it closer would require machining.

Looking for ideas from anyone that had similar issues. The box is grounded to the battery. The voltage to the MSD is within spec over 11 volts while cranking. Hooked MSD to another lone battery with 12.8 volts and it still would not start.

 

Msd told me that the ground from the battery should go to the head not the block. And then ground the box to that spot. Then run a jumper to the other head. They said that it is very important to ground it this way.

 

Yes, Battery in rear and ground goes all the way to the battery.

MSD tech thread.
Stuff for anyone else having to troubleshoot their MSD 6010.

http://www.msdignition.com/forum/showthread.php?t=20599

Stuff I have picked up elsewhere.

Brown wire on cam sensor should read 8 volts

violet wire on Driver side coil pack should read 5 volts

Orange/yellow wire on crank sensor should fluctuate 4-8 volts while cranking.

Orange wire on main harness should have 5 volts.



If any of this information seems off lmk.

 

I had different problems with a 6012, mine was cam sensor related. Yours definitely sounds like it is crank sensor related.
A 408 is obviously an aftermarket crank, I would suspect the aftermarket crank reluctor wheel.

 

That is some very good info. Thank You for posting that.

 

Be sure your cam sensor wires are not reversed. The two outside wires were reversed and caused some of your symptoms you are having . I reversed them and problem solved . Just something to think about and check.

 

That is a problem for a 6012 with no factory GM cam sensor harness.

 

This is what I'm afraid of.

Its not looking good ATM.

 

The motor hits on all eight when it runs. The crank sensor reads 8 volts at the yellow/orange wire keyed on. Then when rotated by ratchet it pulses below 3.70. turned by key the pulses never reach 8 again... hell they never get to 4.0 volts at any time.

I have tried two known good boxes and 2 harnesses. 3 crank sensors off running engines. Same problem. I am hoping someone can give me some direction here. 1000.00 for a distributor set up is a crazy expenditure when I bought this engine as a short block built by a sponsor here. I would think they would know whether the cranks they sell need extra work to make run with a MSD. Or won't work with the MSD.

It sure does seem like the reluctor needs to get closer to the wheel or the signal just needs to be stronger (more volts). Thus the reason it cranks with the battery at 14.2 volts. And probably the misfire like the box is low on voltage.

WTH.

 

Contact MSD. Maybe they can retune your box to the lower signal.

I remember this problem use to be common in the early years of the box. Guys with aftermarket cranks had this issues. MSD made some firmware changes to get the thing to work for quite a number of guys. But there was still the occasional guy who had no luck.

FAST makes an ignition box for LS motors. It is also possible to use a stock PCM. I would bang on MSD first.

 

You could use a Megasquirt to run the ignition if you had to

 

I am trying to get MSD to help me on this. I think I just have to get the right tech. The techs I'm getting on the phone say there is nothing that can be done. They say all the new boxes have the updated firmware.

 

Do you have any links to this being done?


Thanks for the responses.

 

No I dont. But there are many using Megasquirt for full efi. I beleive you would need MSII, or higher to get ignition control. The Micro squirt unit can run LS ign too.

 

More great news... I now understand why MSD is bankrupt. Wonder why the starter won't clear my headers. Pictured next to old starter I had laying around. That pic is after clocking it the one notch you could go towards the block. The next option is clock it solenoid down which runs into the block. So rather than grind the block and this expensive but nice looking paperweight. MSD will be getting this crap back. Take a good look at the picture. If you don't have fenderwell headers. This starter may not be for you.

The stock starter turns the motor fine, the MSD won't tell it to spark. Great strategy to sell their $300.00+ starter. To bad their starter don't fit anything.

MSD 60952 Picture right here if your searching.

 

I don't know if you got the wrong one or not but i have 2" Kooks long tubes and there is all kinds of clearence. Had to clock it towards the block. Got 13.5:1 compression and it turns it over like its a stock motor. Maybe they gave you the wrong mounting block on the starter by mistake.

 

In that picture the starter is clocked in the one notch toward the block. Stock it will come in the center hole of the 3. Draw a line straight across from the outer bolt hole (the holes used are red X'd, I know you know that, just for reference to others). You will plainly see the amount it will be sticking out past the block.

The 5906 tucks fine, the high speed 59052 is what's pictured and sticks out a lot. The 5906 turns like a stock starter IMO. Never tried the 59052 as it would not fit.

 

Oh, I see what you mean. Sorry I didn't know that. Thanks for the schooling. Mine must be the 5906. It does spin ours over pretty fast at that compression though. We were very surprised.

 

So is the mount actually different width wise, where it mounts? If so is there a possibility you could use the mount off your old MSD?

 

I don't have an old MSD I bought a 5096 ... it wasn't much better than the stock one IMO...sent it back in exchange for the 50952 (High speed) that won't fit. I'm going 16 volts and leaving the stock starter on there.