weak spark with msd 10 suggestions for troubleshooting please

so this weekend had 3 qual shots, plugs started out new and ended up new. I leaned main from 105 to 113 to 128 and even went from 25% to 30% OD Q2.

So i suppose my msd 10 is going bad??

Could this be a coil issue, pickup, or box, or all the above??

I control with Powergrid, what about that??

Thanks for suggestions/advise. I am going testing and need to develop plan to limit the number of runs.

Casey

 

They are no longer made.

 

Spares

I have spares just wondering what to try first? Would pickup cause weak spark?

 

more info to prod some more advice

a few more things to point out to maybe get some more responses.

random cylinders are going dead according to EGTs. I originally thought it was the EGTs. For example, number 5 was showing dead so I changed the egt. on the next pass #5 showed good but then #3 showed dead but plug showed at least a little heat (it didn't look brand new at least). I watched video when it comes off the 2 step and rolls a foot or 2 it throws out raw fuel on the even bank that is not showing dead cylinder. but seems to pick it right back up.

another thing that puzzled me was a carbon on the side of one plug and a carbon ring around the inside porcelian on another. this probably means something, right? BBC 526 BB@ heads 1471 HHR plugs gaped .018

See picture. #6 carbon on side, #7 carbon ring.

 

I ran a 10 for years in my experience the box works or its dead the coils to go away slow sometimes change coil,coil wires go bad the 10 is almost has the same spark as the pro mag. Cycle out coil wires 30 runs or so, and ohm check The other wires run .015 spark gap.Check phase on cap rotor

 

I too run the 10 and a 14 HH I think the gap is the issue, We run 10-12 gap.

 

Changed everything msd component and plug wires. No change. After reaching my biggest pill of 140 I started going up on blower OD and finally got the plugs to start showing a little heat. So I guess maybe it's time for blower restripping. Problem is #7 is dead. Egt and plug show dead as a hammer. I don't know why. It has 0% leak. Compression is same as others. Nozzle is clean. Plug fires when I test it. Really don't know what it could be. Any ideas? Plug gap is .18 what I have run since 2009. I checked all my poppets. Rotor phased. Cap looks good I cleaned the electrodes.

Any more ideas?

Thanks

 

Change the plug wire?

 

wires

There has got to be a problem in the wires-ck ck ck

 

Check all of the parameters in the grid. Individual cylinder timing should be off, check firing order , max timing .... Everything. Then fire it up and cycle the t brake and watch the retards come and go live with a timing light. I quit the grid because of shit like this, doing shit for no reason and then breaking at the worst possible time. I bet I bought 4 or 5 of these things. Love them when they work, but they are just not reliable enough. Switched to a control module from leahy, like it just as much, just the price that leaves you butt hurt.

 

weekend update, still searching for suggestions

so this weekend, did the following and still #7 dead (~100 degs), #5 400 degrees lower than rest. made 5 passes.

tightened plug gap to .012
unplugged power grid
changed plug (one of many tries)
changed plug wires (3rd set)
changed distributor cap
leaned #7 port nozzle from 45 to 43
changed pickup cable
tested magnets with paper clip (if I had a weak magnet it would show on different cycles)
checked grounds (I have grounds on heads already)

so all this is in addition to all the changes made in other test sessions listed above

I compared #7 and #8 nozzle flow in a water bottle at 5000 rpms for a few seconds. #7 was just slightly less, really don't know if that acceptable or should they be exactly the same?

no matter what I have done nothing changes on #7, plug ground strap burns coating down to weld but rest looks brand new.

really at a lose here. Should I keep leaning the nozzle? check intake gasket? try power grid power source instead of 10, could it be the fuel pump?

Thanks ITA for your help.

 

1: When in doubt about the fuel side, richen it up first.
2: IF you go really, really lean and then go really, really rich and nothing changes in either direction the ignition is toast.
3: In the case of boxes a new battery can do wonders.

Dave Koehler
http://www.koehlerinjection.com

 

With the 10 plus the plug gap is not the issue. I ran over 40 psi at .028 gap for years without issue. Now a mag would be another story.

You did change the coil wire right?

Try the grid instead of the 10 plus. That should isolate the problem area.

Blessings..........Ron

 

new ideas

Ron, yes, changed the coil. I have the exact same blower and fuel system on other car. I am going to try that one and check the the intake gaskets as well while I am in there.

If that doesn't work will try the grid power supply.

Dave - have alternator, should take care of voltage right?

thanks for you help.

 

Alternator good deal, You might want to have it checked by a specialist since you are digging deep.
They do some weird stuff occasionally and only an old school specialist will have the know how to check it in depth. Autozone won't.

Dave Koehler
http://www.koehlerinjection.com

 

intake good

Intake checked out good.

Battery voltage shows 12+V on data logger.

 

Update

Thanks everyone. I changed the egt on #7 and something very weird happened that hasn't happened during the three races and 1 test session that I have been fighting this. #7 showed 1200* which was same as rest. . Plug still looked new. . #5 was 400* colder like previously explained. :/. Now here's the kicker. #1 showed 100* and plug was black! ??? Et slowed .08. So Looks like maybe egt was bad and #7 is just fat? But now what happened to #1?

Plan: I have another car with same blower and fuel system. I have taken blower and entire fuel system and put on this motor. Now we will see if fuel or air or spark!

Thanks for suggestions.