MITSU CAS differences [now TBI to MPI conversion] ??
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Author:  j2dapo [ Mon Nov 26, 2007 4:41 pm ]
Post subject:  MITSU CAS differences [now TBI to MPI conversion] ??

I' looking into changing my TBI 2g CSM to MPI using a 4g15 CAS distributor with a 4g6x turbo ecu.

Will I have any issues trying to use the 4g15 CAS distributor signal with a 4g63 turbo ecu? So far I have a 4g63 wiring/ecu/maf/injectors from a 92 Laser RS AWD. I will use a 4g37 manifold with a 4g6x TB. Lastly is the CAS signal, and I think a 4g15 distributor will work, it fits the head and internally lools like a 4g61 CAS and has a similar connector.

I think this will work, any input is appreciated.

Author:  Evotistical [ Tue Dec 04, 2007 6:51 pm ]
Post subject: 

If your engine is a stock 1.5, I can't see how it will work but hey give it a try and do a writeup. Mabe your better off doing the 4g63t swap or turboing your 1.5 :wink: You might have better luck with a g32b/4g37 parts setup.

Author:  j2dapo [ Wed Dec 05, 2007 1:59 pm ]
Post subject: 

Yup this is for a g32b.

At home I have two optical plates one from a 3G CSM 4g15 (8 valve?) Distributor facing firewall - and the other from a 4g61 elantra CAS.

They are physically the same except for the TDCS slots punched on them. The CAS slots are at the same angles. I took the elantra CAS plate and installed it onto the 4g15 distributor. (pics to come)

I also need to figure out if the why the Cyl 1 TDCS slots are at different angles on these two plates. Could have something to do with DOHC vs SOHC and the plates installion angles in relation to the crankshaft.

I need to look at more of these plates (and brush up on my Jr. High geometry). Specifically a Mitsu 4g63 optical CAS, (anyone know if they are the same as the elantra CAS). I will go the the wreckers and look at other CAS plates. Finding will be documented!

Author:  j2dapo [ Sun Dec 23, 2007 3:21 am ]
Post subject:  Some pics and findings

Since the DOHC CAS is mounted on the rear of the engine it rotates CCW. SOHC distributor CAS rotate CW. At first the timings listed in the ref book where odd compared to the slots on the plates - nothing seemed to line up. Once I ripped appart the led pick up it all made sense; the two leds are not at the same angle! I think all I need to do is place the DOHC plate on top of the SOHC plate and mark/drill out the missing cylinder 4 TDC slot.

Here is a pic of the plates

The DOHC 4g6x timings

The SOHC 4g15 timings

My assumptions are that, all 4g6x CAS are all interchange and that the 4g15 distributor will provide the same CAS/TDC signal to the ecu as a 4g6x CAS. I've read about people swapping CAS between years or NA FI 4g6x engines. The ECI Multi reference book also states that the 4g15 CAS/TDC signal is the same. I need to collect a few more parts before I attemp the conversion.

Author:  Berserko [ Sun Dec 23, 2007 5:30 am ]
Post subject: 

I've actually looked at this at some point in the past I was interested in making my 4g15 distributorless and adapting in a coil pack (Why I don't really remember probably just to say I did it) the actual base between the distributor and the coil pack were different the distributor had a much bigger base.

Here is what I would do if it were me.

Take everything from a 4g6x coilpack, CAS etc get a collar machined for it so it fits in your g32b and run everything that way.

Get everything from a 4g37 ECU/MAF/Distributor and all and find a eprom ECU and hack in all your fuel/timing maps into the ECU

Porobably of of those solutions are easier to do then hybriding it up.

Author:  j2dapo [ Mon Dec 24, 2007 3:14 am ]
Post subject: 

The plan is now to do the first. (still need the 4g37 manifold, fuel rail) The 4g15 distributor it fits the g32b head just like the original dizzy.


The aforemethioned 4g63/4g15 plates are physically the same size. When I stack the plates all the CAS slots align up as well as the center slot. All Im going to do is align the cylinder 1 TDC slot on both plates and mark where I need to add the missing 4th cylinder slot on the 4g15 plate.

This car is my daily too, so things will go slow...

Author:  Evotistical [ Mon Dec 24, 2007 3:22 am ]
Post subject: 

Awesome job so far :P

Author:  MonoxideChild [ Mon Dec 24, 2007 3:45 am ]
Post subject: 

very impressive. hope you keep on it. your covering new ground for us G32B owners

Author:  Berserko [ Mon Dec 24, 2007 6:57 am ]
Post subject: 

Crap a totally forgot about that style of distributor being on the back of the head. I always had the later version that plugged into the side of my head.... right onto the cam

Author:  j2dapo [ Tue Dec 25, 2007 6:50 pm ]
Post subject: 

IIRC, the distribtor facing the firewall 4g15's are the 8 valve engines. The ones with the distributor on the back of the head facing the tranny, are the 12 valve enignes. (some1 please correct/confim this)

The plate in the picture not labeled above belongs to one of those 12 valve engines.

Merry Xmass!

Author:  Berserko [ Thu Dec 27, 2007 10:33 am ]
Post subject: 

Right back of the head = 8v
Left side of head = 12v

Both my colts and all my colt engines were 12v units

Author:  Dennisglxi [ Sun Dec 30, 2007 9:52 am ]
Post subject: 


some months ago i had al little ill idea. i have a c50 (3g) colt, a 4g32t engine and many misc parts in my garage. lets do a low budget project.

why don?t build a 3g colt with an 4g32t engine? so a friend of me and i try to get this eci engine to a mpi.

so we used a 4g37 manifold, but it is not 100% the same:


the 4g37 manifold has no chanal for the water, so i cut a water chanal from a 4g63 sohc manifold and make it fit for the 4g32t head:


but the bolts in the head are to short to fix the manyfold to the head, so we used screws:


now the manifold fits perfect to the head:


we also want to use the 4g15 8v distributor, 4g15 12 v wiring (we have to chance something), 4g37 ecu, 4g63 sohc maf, 4g63 sohc throttle body.

Author:  j2dapo [ Thu Jan 24, 2008 1:10 pm ]
Post subject: 

Sorry never saw this post, very informative, I will change the OP title as to expand the scope of this thread (TBI->MPI). Thanks so much for all the pictures.

Nice idea with the thermostat, I assumed that we could use the same thermostat setup from the 4g37 on the g32b? (I still need to find 4g37 parts)

On my part - I've also fitted a SOHC 4g63 distributor onto the g32b head. I assume mitsu did the same as far as the CAS/TDC sensor and its timings. This distributor has the later 91-94 DSM type CAS/TDC connector which matches the harness I have. (The 4g15 8v distributor has the 90 DSM type CAS/TDC connector)

I have so many more questions for you.
  • How does the SOCH 4g63 TB fit the 4g37 TB.
    Can you comment on the SOCH 4g63 TB's size and the sensor/connectors compared to a DOCH 4g63 TB?
    How will you be controling fuel?
    How will you be controling timing?
    Why the 4g63 soch MAF, wont the 4g37 MAF work better with the 4g37 ECU
Please keep the information flowing and best of luck!

Author:  j2dapo [ Tue Feb 26, 2008 12:10 pm ]
Post subject: 

Picked up some parts, unfortubately I have a 89-90 4g37 IM which has a funny TB bolt pattern. I need to get a older 92-94 4g37 IM so that I can bolt up a 4g63 TB.

You can see the TB gasketon the left in the first picture with the non-square bolt patern on the early 4g37 IM. The 4g63 TB gasket is on the right.

The shinny bits are the results of my new sand blasting cabinet, 8) .

I drilled/filed out the missing cylinder 4 slot in the TDC/CAS plate, and am using a SOHC 4g63 distributor because it has the right type of connector for my 92 talon wiring harness.

The choice of wiring harness is important as it dictates which TB and Distributor you can use because of the connectors on the wiring harness.



Author:  MonoxideChild [ Tue Feb 26, 2008 6:58 pm ]
Post subject: 

very nice. keep us updated!

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