Outer Limits 4x4 Board

Hi all
I have a duel fuel 4.2 carby Maverick. Was running ok but not great.
Fitted a Pertronix yesterday and a GT40 coil , started it up. Was idling heaps better and starting easier. All seemed good.
Took it for a drive this evening and the problems started.
Straight away when I hit 3800revs it started surging , missing and a couple of pops out the exhaust. This was on LPG. Turned it over to Petrol same thing happened.
Took it for a bit of a drive , found the temp was starting to climb a bit and the higher the temp got the worse the running was. It was starting to miss around 3000.
Got it home ok and free reved it to 3500 miss and stumble was there.
I know its not fuel related because it does it on both LPG and Petrol.
So it is missing both free reving and under load. Idle seems fine and it pulls well up until 3000. It is easy to start too.
I have not touched the timing because I didnt pull the dizzy out of the truck to fit the Pertronix.
Any ideas where to start looking? I thought if it was an electrical drama it would be there all the time not just higher in the rev range.
The cap , leads and plugs are still the original items from the old points setup. There didnt seem to be a problem before.
This one has me scratching my head!
Any ideas or help appreciated.
Matt

you did reset the timiung after fitting it didnt you

As i posted up the top in the description of the problem I have not touched the timing because I never removed the dizzy or adjusted the timing when I fitted the Pertronix.

i would say that the coil is not up to it mate

I hope it aint a coil problem. Its a new GT40 like they recommend with the Pertronix. Something to look at but.

A GT40 or GT40R? Have you bypassed the ballast resistor? The GT40r is a low voltage coil designed for a ballast, unfortunatly the Nissan ballast is specific to the Nissan coil, you should buy a generic ballast if using a GT40r or you should bypass the ballast if using a GT40(12v) coil.

Joel

Its just a standard GT40. The ballast has ben bypassed and removed. After talking to a few people Im thinking the timing may be too advanced. I have never touched it since I bought it so who knows what it was set up on.

Check the cap. The extra voltage with electronic ign could be tracking in the cap. Is there a loose wire in the dizzy? I had electronic ign on one of mine & it just stopped & wouldnt go again . Ended up being the cap.

Kyle

Make shaw that the black wire that origanaly went to the points is not flapping around i have had probs with back firing cutting out and surging with wine. It conked out at a major intersection on tuesday wouldnt start again. Turns out that that black wire was jumping around and earthing out on the dizzy.

ZOOK60 wrote:Make shaw that the black wire that origanaly went to the points is not flapping around i have had probs with back firing cutting out and surging with wine. It conked out at a major intersection on tuesday wouldnt start again. Turns out that that black wire was jumping around and earthing out on the dizzy.

Do ypu mean the little black bridging wire that went from the dizzy body to the points plate? I left that on there and put it back under one of the screws thinking it was an earthing cable and had to be on it.

yes i think that is the one mine is now tapped up and cable tied out of the way so it cant earth out any more

Well I think I found the problem. The timing was set at 20 btdc .
Put that back to 10. Splutter still there and getting warm lifted the radiator cap.................nice little steady stream of bubbles.
Not happy Jan!