Sanity check no start

Ayles · 11:15 AM

I drove car on Wednesday and it ran beautifully with no issues.

Went out yesterday afternoon to take my nephew for drive and it wouldn't start though it cranked strong and shows good fuel preSSure on my preSSure guage. Sounded very much like no spark.

I have an msd 6al/msd blaster SS 8207 coil, and an Odyssey 925 battery.

The battery is showing 12.5 volts.

I pulled a spark plug wire and plugged in a new spark plug and verified I am not getting any spark.

I tested the coils resistance and found the primary resistance is .6 ohms while spec is .355 per the msd site. The secondary resistance appears to be in spec.

Would that be enough to cause a no spark condition? The coil is about 15 years old but wasn't ever used until a month or two ago. But it is the solid state version so not sure how they age without being used.

The odySSey battery also sat on my shelf for 1.5 years but it seams to be working fine.

Anything else I should be looking at? This reminds me other coil failures I have had in the past. Where the car drives just fine and all of a sudden it wont start.

john walker's workshop · 11-27-2015, 10:59 AM

Maybe trash the MSD system and go back to the original Bosch 6 pin box. They're hard on ignition components. See if your rotor is fried.

Ayles · 11-27-2015, 11:14 AM

Checked the cap and rotor and they are pristine and almost new looking inside.

gomezoneill · gomezoneill's Garage

Check the green wire that feeds the pulse from the hall effect coil in the distributor they can fail. Check the resistance of the hall effect coil in the distributor also they will fail and cause a intermittent start problem. You can check the hall coil with a ohm meter (analog) while cranking you should get a pulse that's what triggers the cd unit to spark.

Ayles · 11-29-2015, 09:05 AM

Thanks Gomezoneil,
I went through all the msd test procedures and swapped in the battery from my daily driver. Additionally the odyssey battery started my dd no problem so I am ruling out the battery.

I do have power on the main line from the starter.

Also tried the false trigger test and couldn't trigger a spark and I don't have any juice on the small red wire.

I did learn that the msd box was purchased in 1998 and not used until I installed it a couple months ago. Not sure what the shelf life is on one of these...

I ordered a new digital 6al and will give it a shot.

T77911S · 11-30-2015, 02:03 AM

based on the newer MSD, you need switched power on the small red wire to turn it on.
power on the large red wire is there all the time.

check grounds.

Ayles · 08:28 AM

Quote:

Originally Posted by T77911S

based on the newer MSD, you need switched power on the small red wire to turn it on.
power on the large red wire is there all the time.

check grounds.

I had my MSD grounded at the fuse panel where a couple other wires are grounded.

I had seen this done in other installs, is it not a sufficient ground?

I am using a factory style plug that I put together with help form Timmy2 so my thin red wire was plugged directly into the harness.

T77911S · 11-30-2015, 08:38 AM

both reds have to have power. use a test lightor both that and a MM. a MM will measure 12v but there may not be enough current to run the MSD.

mine is grounded on the same silver plate but it is tied in with the ground wire that goes to the body. IE the fuse panel may not be grounded to the body.
MSD strongly suggests running a seperate ground directly frmo the MSD to the battery.

Ayles · 11-30-2015, 09:05 AM

Routing a ground to the battery is going to be difficult, would running it to the transmission ground strap work?

With the key in the ON position I did not get any voltage at the small red wire but did get voltage on the heavy red wire from the starter.

T77911S · 12-01-2015, 03:32 AM

just make sure it is grounded for now.

you said no power on the small red wire? check that .

mine is not grounded to the battery. not sure how i am going to run it yet. was going to look at running it under the car with the AC hoses but only if i can hide it good enough. just a thought.

Ayles · 12-14-2015, 09:42 AM

To update this thread.

I went through all of the MSD test procedures, picked up a new coil, checked grounds etc... and had no luck. I picked up a new MSD 6al digital last week and wired it up yesterday. This was a good opportunity to redo what I installed before and upgrade things a bit with more shrink tube and just a slightly cleaner job all the way around. A lot easier when have done it before.

The new msd box has a indicator light that shows the unit is actually getting power, where the old one did not.

Plugged everything in and it fired right up, all signs point to a failed msd box.