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4jg2 pump conversion, IDI to DI and Right or Left spin

Getting the best performance from your Isuzu
muffinmonsta
Posts: 6
Joined: Fri Jun 15, 2018 9:31 am

4jg2 pump conversion, IDI to DI and Right or Left spin

Post by muffinmonsta »

Good day Gents,
is it possible to convert a 4jg2t idi pump to work on a 4jb1t?.
if possible what mods are needed?
tonkamu
Posts: 109
Joined: Sun Jan 01, 2017 9:18 pm

Re: 4jg2 pump conversion

Post by tonkamu »

Won't the map be way out? the computer is for a 3.1 with indirection injection different size injectors. But im not an expert
But the answer is yes anything is possible hehe
muffinmonsta
Posts: 6
Joined: Fri Jun 15, 2018 9:31 am

Re: 4jg2 pump conversion

Post by muffinmonsta »

tonkamu wrote:Won't the map be way out? the computer is for a 3.1 with indirection injection different size injectors. But im not an expert
But the answer is yes anything is possible hehe

no computer all mechanical
isuzurob
Posts: 480
Joined: Mon Jun 18, 2012 3:25 am

Re: 4jg2 pump conversion

Post by isuzurob »

The cam plates are different, and the plunger is meant to be bigger in the 3.1 pump but they bolt straight on to a 4jb1 and work well, well mine did anyway
muffinmonsta
Posts: 6
Joined: Fri Jun 15, 2018 9:31 am

Re: 4jg2 pump conversion

Post by muffinmonsta »

Planning to use a G2 pump with the B1 cam plate. But will the injection pressure get up to B1 level?
isuzurob
Posts: 480
Joined: Mon Jun 18, 2012 3:25 am

Re: 4jg2 pump conversion

Post by isuzurob »

Mine ran ok with a standard 4jg2 pump on a 4jb1, just slapped it on and was away
muffinmonsta
Posts: 6
Joined: Fri Jun 15, 2018 9:31 am

Re: 4jg2 pump conversion

Post by muffinmonsta »

OK then that sounds good, because for the life of me I can't get my hands on a working jb1 injection pump
tonkamu
Posts: 109
Joined: Sun Jan 01, 2017 9:18 pm

Re: 4jg2 pump conversion

Post by tonkamu »

Hey guys, on the mech pump for 2.8 can you control how much boost with the compensator adjusted and tap screwed in if the turbo is free spooling/waste gate not connected?
Currently only reaches 18 psi with wastegate not connected the fuel screw has been screwed in quite abit that my idle screw is no longer in use and idles at 800. My understanding of the boost compensator is limited and I've never touched it but I bought this car with factory turbo that boosted to 18. I've fitted a vf10 with vf10 exhaust housing and 2.5 inch downpipe since then. increase in power has been insane, the whole front lifts up and bottom sits down at 90kph flooring it, no smoke. I have a boost tap I can only get 10 psi with the boost tap with 12 turns out when its connected. I'm just trying to understand why its only 18 psi when boost tap not connected and not greater, whats controlling it?
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geeves
Posts: 1980
Joined: Mon May 11, 2009 1:56 am

Re: 4jg2 pump conversion

Post by geeves »

Have you removed the pressure release from the inlet manifold? This should be releasing at 16psi though so could be where the boost is going
tonkamu
Posts: 109
Joined: Sun Jan 01, 2017 9:18 pm

Re: 4jg2 pump conversion

Post by tonkamu »

hey geeves, yes its been taken off and blanked up. How do other people get 30 psi with no wastegate, I can't turn fuel in anymore as the idle/throttle is hitting the stop assembly. Is the adjustment at the compensator in order to get more fuel in under boost thus making more psi? cheers
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