Stutter at higher rpm...

51MAN · Post by **51MAN** » Sun May 25, 2008 11:59 am

Ok , not so high rpm , but prob 5k ish.. wich is high considering its a 2.1 DJ running on the stock 1.9DG carb and manifold..

Seems to be an ignition related problem.. wont pull to the "change point" on the speedo (no rev counter) change point would be around the 5400 rev limit rotorarm
I have new cap and rotor (non rev limit)
leads are newish.. as are plugs..
Carb has been rebiult and is clean etc...
Not very old fuel pump and I am sure it isnt fuel related as I have a lambda sensor and simple display which shows rich...

timed up at 10 deg BTDC (running on 98UL) and tried 5 deg and even 0 just to see if I was running off the end of the rotor (rotor shows last 3rd of the the metal as the "jump point", if that makes sense)
gonna check the earth and even swap out the ignitor for a known good one.. but after suggestions...

tencentlife · Post by **tencentlife** » Sun May 25, 2008 5:09 pm

Coil.

I've also heard that lesser plug wires than Bosch Ultra Premium exhibit this behavior.

Post by **Piledriver** » Sun May 25, 2008 7:12 pm

They make a rev limter rotor for the wasser hall effect distributors?

51MAN · Post by **51MAN** » Mon May 26, 2008 3:54 am

Will swap the coil as well.. but normally a coil will show fail under load no matter what the rpm is.. its fine under full throttle from low rpm, until it hits 4500 ish I reckon..
Leads.. I can swap too, but they are good quality hella ones..

Yep they do make a rev limited rotor for them, fitted as standard..

I will swap out part by part as I have my Syncro doka I can take parts from.. that revs to 5k no problem..

tencentlife · Post by **tencentlife** » Sun Aug 24, 2008 11:39 am

If you have the Hall effect diz, this is a common problem when the insulation on one of the three wires for the diz connector gets a crack in it. The cracks can be hidden inside the harness sheathing so it can be an aggravating problem to isolate. The problem usually surfaces after a diz or engine R&R when the harness branch to the diz gets manipulated and bent. The insulation was cheap to begin with, and by now they're all old and brittle. The worst is where it is actually exposed, so if you're lucky the damage is limited to an area you can see.

51MAN · Post by **51MAN** » Sat Aug 30, 2008 1:19 am

Cheers Chris.. didnt think of that.. will take a look when I am back there..
Gonna PM you tonight..

Si

tencentlife · Post by **tencentlife** » Tue Sep 02, 2008 4:42 pm

Yeah, the problem crops up pretty often. It's the center green wire that returns the signal to the ECU. It seems to be the most sensitive to wire damage.