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ZJ 4.0 Injector upgrade
Posted: Sun Jun 12, 2011 1:20 pm
by tga_4x4
Just done a VT Injector upgrade, removed the Chrysler single point injectors and fitted 4 hole GM items, straight away I noticed that I did need as much throttle pressure (seat of the pants dyno)
as before, not sure if its psychological or not but even around town feels different, not sure if it will effect fuel economy, but logical speaking 4 hole mist injector should be better fuel burning than a single point ..??
Re: ZJ 4.0 Injector upgrade
Posted: Sun Jun 12, 2011 7:24 pm
by xj
tga_4x4 wrote:Just done a VT Injector upgrade, removed the Chrysler single point injectors and fitted 4 hole GM items, straight away I noticed that I did need as much throttle pressure (seat of the pants dyno)
as before, not sure if its psychological or not but even around town feels different, not sure if it will effect fuel economy, but logical speaking 4 hole mist injector should be better fuel burning than a single point ..??
part number?
Re: ZJ 4.0 Injector upgrade
Posted: Sun Jun 12, 2011 8:29 pm
by tga_4x4
VT onwards Commodore 0280155777 ,got some at pickapart today for $32, straight forward replacement, injector plugs the same , just plug and play

Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 10:46 am
by Smurf
Just bought a 96 Grand cherokee, let me know if it helps your economy.
this could well be my first mod.
cheers
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 10:57 am
by xj
Smurf wrote:Just bought a 96 Grand cherokee, let me know if it helps your economy.
this could well be my first mod.
cheers
what???? doing that BEFORE the lift and 33's????
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 11:15 am
by Smurf
xj wrote:Smurf wrote:Just bought a 96 Grand cherokee, let me know if it helps your economy.
this could well be my first mod.
cheers
what???? doing that BEFORE the lift and 33's????
yeah , well I'm broke now...
looking at lift kits now to fit the 33s, Coz I think the 35s off the Surf just aint gonna fit.
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 12:49 pm
by SMOKEY
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 12:51 pm
by Smurf
er yeah,

still, got to be more economical than Leos old girl, that 350 diesel is a hungry puppy.
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 5:44 pm
by tga_4x4
So far so good, feels alot better underfoot and easier to drive around if that makes sense , I am still looking into lifts kits myself, not sure where to go on that one..
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 6:53 pm
by coop
Are they V6 or V8 injectors?... they seem to be on ebay.com.au for AUD 180ish new.
Have you done an economy test yet?
If I could turn back time I probably would have spent an extra grand and got something like this instead of the 'budget' 3.5" I bought. Mainly for the upper control arms, and adjustable track bars. An extra 2" lift and the room for 33s would be good too.
http://rustysoffroad.com/mm5/merchant.m ... sus_zj_kit
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 7:13 pm
by xj
oi coop, wheres them photos?
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 7:42 pm
by tga_4x4
coop wrote:Are they V6 or V8 injectors?... they seem to be on ebay.com.au for AUD 180ish new.
Have you done an economy test yet?
If I could turn back time I probably would have spent an extra grand and got something like this instead of the 'budget' 3.5" I bought. Mainly for the upper control arms, and adjustable track bars. An extra 2" lift and the room for 33s would be good too.
http://rustysoffroad.com/mm5/merchant.m ... sus_zj_kit
V6 Injectors, read a few aussie forums and they seem to say the V6 injectors flow the same as the jeep anyway, the V8 ones would be ideal if your running a tuned motor, but how much can you tune a jeep motor before it goes bang ??
So a 3.5 inch lift a waste of money ??
Re: ZJ 4.0 Injector upgrade
Posted: Tue Jun 14, 2011 8:02 pm
by coop
Wouldn't go as far as saying it's a waste of money, good for a mild off roader, but try and land some longer upper control arms to suit (or adjustable) as the supplied transfer case drop isn't enough to get rid of driveshaft vibration. If its a daily you'll definately want this.
Reading the yank forums they say the 5.5 or 6" long arm kits ride and drive as good as a standard one but you'll pay big bux for it.
xj- still gotta get some pics and vids off the flatmates iphone, should be tomorrow night.
Re: ZJ 4.0 Injector upgrade
Posted: Sat Jun 18, 2011 9:32 am
by tga_4x4
Well just done a comparo with 25 litres of fuel before and after injector upgrade, seems to be that i got 20km more before the light come on with the new injectors, also found it has stopped a surge it used to have under acceleration, so in all so far seem to be all good..now time for the suspension lift

Re: ZJ 4.0 Injector upgrade
Posted: Tue Aug 09, 2011 7:51 pm
by Smurf
I dropped a set of these injectors in a few weeks ago, can't say I noticed any improvements, maybe a bit lighter on the juice but nothing noticable, maybe I'll put the old ones back in for a week and do a decent comparison.
I have found it isn't as strong on hills as it was with the old injectors, I now have to put my foot down to keep it at a speed that it happily held itself at with the old injectors.