pcmhacking.net

hi guys
i have just got my hand on a rb gemini for free yep free
it was my old boys car and he got hit up the bum
it a easy fit but he wont drive it again

so its now my runabout and im thinking of chucking the carb out
and setting up the TBI out of a holden astra

what options do i have when it comes to tuning it
can i use my real time board with it
or do i have to do it the hard way

ant ideas or help would be great guys

cheers
mick

if you can get a JE camira loom and injectors and make it fit while chucking the TBI, then you should be fine. Open the dis, and there are 2 modules inside, the further away one is the ignitor, so remove that and connect the first one in to the camira module and you should be sweet for MPI. Take the manifold of a rodeo 4ze1 if you need, should bolt on. The you should be sweet for OSE12P or S. Hmm the 4ze1 TPS signal is not 0-5v range, so you'd need to do something there, though.

i know that the MPI will would be better and i have the parts here to do that but
thats more work then i wanted to do

but if it comes down to that or
burning testing burning testing
then it might work out easier to go MPI

im not looking for any horse power gains
but the cheaper it is to run the better

how would a MPI bin go if it was run on TBI set up
what problems would i run in to

hmm well now i dont claim to know for sure, but as vl400 has added 2 cylinder support in TBI mode to OSE12P, i think you could just run it... you'd need to extrapolate a fuel mapping from the orignal bin, or come up with one yourself, ignore the spark mapping as that would not be relevant in an RB as its under mechanical advance controll, but yeah, should pretty much just work.....

it wont be under mechanical advance for long
i know i have the tools and technology to fix that with no probs

antus wrote:hmm well now i dont claim to know for sure, but as vl400 has added 2 cylinder support in TBI mode to OSE12P

I have only added 2cyl support no TBI sorry guys. Its heaps of work to add it and there are not that many people using it.


There was a thread here that explains what *may* happen with MPI code running on a TBI. I have not tried it so cant say for sure what it will do though.

looks like im trying to push poo up a hill with a stick

how far off would a stock astra TBI tune be
when running on the rb engine

just a up date for any one wanting to know
there is no chance of the MPI manifold of a isuzu 4z engine fitting
so its TBI or a custom manifold and both are going to be a pain in the butt
looks like the carby is staying

so the 4ze1 manifold does not fit the 4zc1? or does the rb have a different engine? thats a bugger, i thought for sure all 4z stuff was interchangeable.

the rb engine is a 4xc1-u its not a 4z

Engine Code: 4XCI-U
Engine Displacement: 90CU IN / 1471cc OHC
Fuel System Type: Carburettor
Power: 52.2 kw @ 5400RPM
Torque: 87 ft.lbs. @ 3400RPM
Bore x Stroke (in.): 3.03 x 3.11
Compression Ratio: 9.6:1
Oil Pressure: 49PSI @ 5200RPM
Spark Plug Type: BPR-6ES11 (NGK)
Spark Plug Gap: 0.040 (in.)
Ignition Timing: 3 degrees @ 600RPM (MANUAL) 3 degrees @ 850RPM (Automatic)
Intake Valve Opens: 17 degrees
Compression Pressure: 178PSI
Idle Engine Speed: 1000RPM (AUTO) 750RPM (MANUAL)
Valve Clearance (in.) (Cold): Intake: 0.006 Exhaust: 0.010

the thermostat is not on the manifold like the 4z
i have 2 sets of 4z runners here i might try and mod a set to fit
but just have to many things on the go at the moment
and dont have time to start one more