GQ TB42

[MD4x4]

When I change down gears I am hearing a popping noise in the exhaust like a backfire.

The engine will idle fine one day and the next it won't idle then stall.

I do not have an electonic dizzy.

What do you think the problem is?

Where should I look?

MD

[blkmav]

Get one of these http://www.ontrack4x4.com.au/index_files/Page545.htm

[BowTieGQ]

The problem is you've got a TB42. Welcome to the club. I hope you like to tinkle with you car regularly. Need more info on things like, what LPG system you've got, what you've already checked etc.

[MD4x4]

Don't have gas.

Just a standard carby.

Its' got extractors and 2.5" exhaust.

Have not done anything about it yet.

Project for next weekend.

Not really sure where to start.

MD

[micks troll]

havin the extractors and 2.5" exhaust will cause it to burble and backfire a bit my motor was reconed 12 months ago and it has extractors and a 2.5" exhaust. If you want to stop the back firing put a resinator or extra muffler on at the exspense of power. i have a so called turbo muffler and it drones badly on the highway and if you back down the gears she farts and carries on but never had trouble with it stalling. maybe you dont have enough back pressure with the muffler thats on. check your leads and dizzy spark plugs even fuel filter start with the easiest first if all else fail see a desent mechanic hope this helps a bit to others with same probs.

[Sexy Fingers]

Check points and condensor. Maybe overfuelling or running rich also. I'd put it on a 4 gas anylizer to check it properly. I've got a 2.5" system on mine also, and it runs sweet. Only differance is, I've got an electronic dizzy.

[MyGQ]

put money on over fueling. Had a TB42 before i rolled her on dual Fuel with extractors, 2.5" system and elect ignition conversion using Crane Cam Fireball.

When decelerating or changing gears if it was below 2200RPM it would burble, when on the freeway at 110K's and i backed off the accelerator it would decelerate without the burble but after she hit 2200RPM it kicked in as she backed down its because of the extractors.

I was told that when you get to a certain amount of RPM you are keeping the exhaust full of well exhaust and air. when you back down it can't keep it full and it sounds like its popping, if its backfiring, as in a bang, then thats wrong, you need to check plugs and fuel. if its just a pop as in a burble its not going to go away unless you go back to standard exhaust. cause mine changed from normal sound to burble after the extractors went on, learned to live with it, as it does sound rather nice when comming off the freeway

[Madmac]

Get one of these http://www.ontrack4x4.com.au/index_files/Page545.htm

yeah i agree, i fitted one to mine, they are easy to fit and you never have to worry about points again.

[shorty92]

i had the same prob and i just got it fixed turned out to be the fuel air mixture screw had a bit of crap in side

[joe crothers]

Madmac when fitting the ignitor do you have to remove the distributor to
grind the ring down on the shaft, to get the magnetic ring to fit on the shaft. Or does it fit with out removing the distributor?
Cheers joe

[henry]

I fitted the Pertronix Ignitor to my TB42. I removed the distributor to do it. It just made it easier to do. You can turn the shaft by hand while holding the grinder in the other hand to make a really neat job. You may be able to use a die grinder to grind the shoulder off the top of the shaft while the dissy is still in the motor but be sure to put rags covering the dissy internals so they dont get shit down inside.

[Madmac]

Madmac when fitting the ignitor do you have to remove the distributor to
grind the ring down on the shaft, to get the magnetic ring to fit on the shaft. Or does it fit with out removing the distributor?
Cheers joe

i removed the dizzy, its only 1 bolt that holds it in. just put a couple of marks on it, so it goes back in right. i ground mine down with a bench grinder

[joe crothers]

Thanx madmac and henry Im ordering mine tomorrow.