rithsleeper

http://vid304.photobucket.com/albums..._150126152.mp4

So unfortunately I changed a ton of stuff at the same time with this new engine but it was unavoidable. Running MSD 6a, Megasquirt 3X ECU, running crank and cam sensors for full sequential which I know can produce some nasty emi/rfi. placed a noise Cap in line to MSD 6a and grounded it at its own ground point on transmission/engine bolt to try avoiding this interference but it didn't fix it.

I figure since the glitch happens to all the displays (even though some displays aren't hooked up like the range and mpg) it has to be either a power spike or ground problem. Possibly an alternator going bad? If it was just one signal wire like the tach input it would affect just the tach display right?

The patterns I've got so far (or don't have). It doesn't follow a pattern according to engine rpm (though it does appear that way in the video. many times it will happen worse at idle than cruising but sometimes terrible cruising and nothing at idle. The only pattern it has is the car has to be sufficiently warm It never happens right off the bat. Always after it has been running for like 10 minutes.

My next play I think is to remove the stock power and ground wires to the Dash and run new wires straight from the battery temporarily to see if that cleans stuff up. Then snip all the wires that aren't being used (which is a lot).

Any other ideas before I get in there?

Hot Rod Roy

You're right. Be sure you have a good ground on the dash cluster. The next trick might be a noise filter on your 12 v. supply line where it connects to the cluster. These can be purchased as "audio filters" in your favorite stereo shop, or you can make your own, like this guy did:
www.youtube.com/watch?v=v0-4sacsv90

ddahlgren

Why not just follow the directions that come with the MSD and connect it to the battery both power and ground and move on from there?

rithsleeper

Connecting the ground to the chassis in all technicality should be a better ground source for eliminating EMI. The power is to my main cutoff switch. Has to be like that for safety and required for lot of organizations track days. I've gone down the electrical fire road..... Msd approves of grounding to chasis also. Electricity takes fastest path back to ground also. If there was a short, and you have a direct route back to battery, then it will take it. Which I don't want to be the Msd unit.

WVZR-1

***Pick up some very inexpensive "ferrite core" clamp-on suppressor/choke for just a trial I'd think or you very likely actually have a few just lying around. Most all AVR come with at least one and some with several. I've never attempted their use for other than their intended purpose but it would be a simple clamp on to attempt.

Very few Radio Shack so maybe not as easy to find but most any audio store might have. They're damn inexpensive.

Here's the first one GOOGLE found for me. I have a few of these just lying around and I've a couple CAT6 cables that came with them also. I didn't look for various strengths but I'm sure there is.

http://www.parts-express.com/cat/cor...ppressors/1458

If you suspect an alternator issue and you mention heat seems to perhaps make it worse could you just remove the alternator belt to check? Is there a capacitor on the alternator now? Which alternator is being used? Is the alternator perhaps a single wire of sorts?

*** This is just a follow to what HRR suggested and maybe isn't a solution at all but a thought.

ddahlgren

What do you have for spark plug wires?

rithsleeper

Hmm. I wonder how well those ferrite things work. Seems so simple I would protect a ton of stuff the same way. My wires are brand new msd 8.5mm. my dist is vortec cam sensor and I've double checked the phasing about 10 times. But then again hall sensors can create a ton of EFI. I'll order some cheap clip ons and if that doesn't work, I'll wire in a filter. Then rewire the dash to its own power and ground. The serpentine is still in the stock setup so can't remove it except for a very brief time. Maybe I can get it glitching then turn. The car off and remove it then run it for a few seconds. Problem is without that waterpump it's going to heat up quick at temperature.

ddahlgren

A hall sensor makes a very nice square wave hey don't make RF or cause any EMI. I have used a pile of different ones for well over 2 decades with no problems. If you still have the original wires in the shop put them on and see what happens. The wires you have are 50 ohm per foot and never had much luck with less than 750 ohms per foot. I have never had any problems with the MSD 8 mm that do meet that spec.