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How do I get go out of 4.2 Petty on gas/fuel

Posted: Mon Jul 21, 2008 6:35 pm
by Gazza the Chippy
Hi, I have a 4.2 93 fuel injected petty on gas, and It's as gutless as all hell, Changed leads, plugs, filters, fuel pump, timing is right, replaced gas mixer. Any ideas as to what to do next, Would love to turbo it but can't part with the $ yet. Cheers Gazza

Posted: Mon Jul 21, 2008 7:26 pm
by jessie928
first check teh filter on the main gas line
check you converter
you may be low on compression, check that
also check that your muffler is not blocked, or your CAT.

Jes

Posted: Mon Jul 21, 2008 10:14 pm
by hokey
Take it to a lpg workshop and get it tuned. made a huge difference to mine. goes harder on gas than it does on petrol.
-Calvin

Posted: Mon Jul 21, 2008 10:23 pm
by PGS 4WD
Provided it is tuned correctly there are some mechanical changes you can make. Extractors and a good 2 1/2 inch exhaust with free flowing mufflers. The standard throttle body is tiny, personally I'd put Gasresearch on it as the throttle body is larger and the system more tuneable, it will make more power than any traditional mixer. You can also chip them to optimize the timing curve to suit LPG/premium and optimize the petrol mixture, the standard petrol tends to run tragically rich under power. I also have a nice camshaft for these that gives an increase in power from 2000 to 5000 rpm without any loss below 2000 rpm, pitty you have to pull the head off for that.
The Gasresearch would be better for the turbo in the future too so it's money well spent.

Cheers

Joel

Posted: Tue Jul 22, 2008 6:38 pm
by BIG GQ
Replace air filter if you haven't already although you said "Filters" so I guess you have?

A dirty air filter and you won't even get it to rev to 3000rpm when it gets real dirty

Will rev on fuel but not gas.

Posted: Fri Jul 25, 2008 3:19 pm
by Gazza the Chippy
thanks for the replies, replaced air filters too, has been tunned at a gas shop, and gas filters all replaced as well. dosent really go hard on petty or gas but gas is slightly better will check compress and look into the gasreasearch stuff, cheers Gazza!

Posted: Tue Jul 29, 2008 11:02 pm
by Walrus4x4
i had simmillar problem with mine and found it was the exhaust put a new 2 1/2 exhaust system and it was like a new car.