Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

VT struggles/backfiring on lpg at revs, what could my problem be?

JAKE-26

New Member
Joined
Feb 22, 2010
Messages
120
Reaction score
0
Points
0
Location
Croydon Hills, Melbourne
Members Ride
'97 VT Exec
Hey all.
I have a vt with dual fuel(exec, auto). When i run it on gas it runs fine and i dont really see much of a performance drop, but when i rev up to about 2300-2600 rpm it always sort of bumps/struggles/backfires but when its not in that rpm range its fine?
Just wondering if anyone can suggest what the problem would be? could it be the computer or something?
it runs fine on petrol, and anywhere out of that rev range on gas.

thanks for any help!
 

jetboy

You learn til u die
Joined
Feb 26, 2010
Messages
243
Reaction score
1
Points
0
Location
Gold Coast QLD
Members Ride
VT exec
Plugs , leads and air filter , any of these or a combination of them will cause ur problem , an yes it will run fine on fuel but not on gas if any or all are stuffed . coil pack could also cause a drama
start with thy cheapest an work ur way up if u dont know how to test these items
 

JAKE-26

New Member
Joined
Feb 22, 2010
Messages
120
Reaction score
0
Points
0
Location
Croydon Hills, Melbourne
Members Ride
'97 VT Exec
I recently put a lukey air filter in but its always done it so i can rule that out.
Plugs and leads could be a good start to tell the mechanic next service. really got no idea how to test any of that lol
cheers!
 

HamaTime™

VIP Member
Joined
Feb 17, 2008
Messages
1,805
Reaction score
55
Points
48
Location
Melbourne
Members Ride
VE SSV G8 & RV6 4Runner
In that specific rev range on gas it won't be the computer (that is I'm assuming you have a carby styled air mixer gas system, rather than direct injection which is ECU controlled).

Check your DFI module, that causes backfiring, though if the problem is rev range specific and fuel (LPG) specific, then the problem will most likely lie with the gas system.

First step is to check leads, coils, DFI, sparks etc...but I'd take it to a LPG workshop to be sure. LPG is prone to problems when all is not perfect, and hard to fix.
 

JAKE-26

New Member
Joined
Feb 22, 2010
Messages
120
Reaction score
0
Points
0
Location
Croydon Hills, Melbourne
Members Ride
'97 VT Exec
Yeah dad (previous owner) told me that the lpg mechanic has no idea where the problem lies but said something about the ecu. I was also told it is a direct injection system so i guess the mechanic could be correct, i just find it weird that it always struggles at the exact rev mark. Whats a DFI also?

It's not the worst problem in the world though. sometimes i just drive it on petrol coz i would like to get above 2.5k smoothly :)
 
Top