COLD START PROBLEM

[4x4xmore]

Hey Guys

I have just recently bought a Maverick petrol/ Gas

I am having dramas with cold starts, when it starts it misses and splutters once idle starts to settle it starts a popping sound. When put under load it backfires. It is near impossible to drive cold. Once warm (about 1/4 temp) it drives great, very responsive, no pinging, doesn't seem to loose power up hills.

This problem is with both gas and fuel...It has been fitted with a crane cams electronic ignition module and a bosh gt40 coil.

I have replaced the air filter for a k&n, also done the plugs and fuel filter. but problem is still there.

The engine compression should be good as I have a receipt for a reconditioned engine that went in around 60,000km ago and the person I bought it of was an elderly gent.

Can anybody tell me what the ignition timing should be for petrol and gas. I suspect that the timing and or distributer may have been incorrectly installed after the electronic ignition mod....

Is this a problem that anyone else has had?
Any suggestions of things to check?

Is there an online manual available for the Mav?

Thanks in advance
Jason

[Froon]

Mate, its a problem I've had since I bought my GQ...

I keep blowing the top off my airbox with the gas backfires...

Mind, I havn't really tried to address the problem - I've tuned the mix but not the timing - I suspect that it is definitely a timing thing...


My truck is currently in the process of getting fixed up for engineering - I'll be getting it dyno tuned in the next few months... Hopefully that'll fix it up for me... Some advice I've been given though (And still yet to follow a year or so later) - I'll get around to it eventually.

All you need to do is take the dizzy out, take it to someone near you that can recurve it, have them set it so it has 12 degrees total mechanical advance all in by about 2800rpm, when you get it back, fit a crane XR3000 optical conversion and piss the points off. get an MSD blaster HVC coil, (thats the off raod version of the blaster 2/3)
when you put it back in, set it with 16degrees initial advance.
open the plug gaps up to 40 thou and fit some eagle leads.
(optional, get an MSD 6A and open the plug gaps to 50thou)

set the valve clearences to factory spec and make sure the exhaust system isn't partly blocked.

once you've done that get the engine hot and adjust the gas mixture screw untill it idles smoothly.
JOB DONE

and then ditch the petrol all together and stick with LPG.

[adriand82]

cant be dizzy or timing. if it was electrical, it would be a problem cold and hot. therefore u probably have a mixture problem, perhaps and air leak somewhere.

[NutterGQ]

back firing on gas is quite often due to weak spark, so check plugs and their temp range, leads and their resistance (type of lead matters too) and if its a 4.2 Points as well!, clean or replace dizzy cap and rotor. All this can be done by yourself and at very little cost and time.