MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

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avguru
John Hilla

(3 posts)

Registered:
04/18/2014 07:43PM

Main British Car:


Need help 3.4 sfi questions
Posted by: avguru
Date: April 18, 2014 08:45PM

I need some help with a ecu for 1994 3.4 sfi engine and manual t5 trans swap. What to keep on engine and what can I take off? I found british car conversions they have a reflash on ecu, do I need to do this? What other parts do I need to get? What company has the best parts for conversion and do they help with info or does someone sell a book on 3.4 swap info?

Thanks John


BWA


(344 posts)

Registered:
04/13/2010 08:13PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: BWA
Date: April 18, 2014 10:07PM

If you go with British car Conversions you will need all of the sensors except for the crank sensor that is on the side of the engine block and the rear oxygen sensor. You will have to keep the crank sensor that mounts on the front cover. I think the 94 has two oxygen sensors one in the header and one down by the catalytic converter, this one can be deleted
The 94 ECU is OBDI so I think that you could just get the ECU reflashed to bypass the ignition key issue and if the ECU was controlling an automatic transmission and I think you are good to go with all of the sensors including the internal crank sensor.
On my 2003 3400 (which is OBDII) we modified the existing harness and used both the front crank sensor and the internal crank sensor along with all of the other sensors and we removed all of the extraneous stuff. We then got a local shop to re-program the ECU. The engine runs really good.
If you are leary of doing your own harness and getting someone to re-program the ECU then I suggest you get the harness and ECU from British Car conversions. If you cannot get anything from BCC (the owner Marc has had some health issues) then you will have to pursue other options.
You can contract Brian at [bmcautos.com]
Or you can contact Bill at [www.classicconversionseng.com]
I hope this has been of some help to you.

Cheers
Byron


avguru
John Hilla

(3 posts)

Registered:
04/18/2014 07:43PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: avguru
Date: April 18, 2014 11:32PM

Yes that helps, BCC has a better website and the only reflash for ECM that I could find, don't know how to find out if Marc is still able to do any work? Do you know any other company can reflash ECM like BCC?


BWA


(344 posts)

Registered:
04/13/2010 08:13PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: BWA
Date: April 19, 2014 12:04AM

Try sending an e-mail to Marc using his website and see if he responds, if you get no response then I would send an e-mail to Brian on this website using his name BMC. Brian's company does these 3.4 conversions into MGB's and I am sure he would be very helpful as they do both fuel injected 3.4's as well as 3.4's with carbs.
I live in western Canada and the outfit I went with charged me $520.00 Canadian to reflash the ECU. This may seem a little steep but any future work on the ECU is free. This outfit does not like to dumb down the ECU for an engine with only one crank sensor when it was designed to run with two crank sensors. So if you decided to go with this outfit you would have to carefully redo your harness and tell the programmer at this outfit exactly what you have done.
I would contact Brian if Marc is not available as I think he will be able to steer you to an outfit that is closer to where you live.

Cheers
Byron


DocsMG
James Spradlin

(40 posts)

Registered:
04/17/2014 01:34PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: DocsMG
Date: April 19, 2014 11:22AM

BWA, you are close but not accurate. The 3.4 needs both sensors and BCC does not program them out. You also need 2 O2 sensors one for each manifold. I put mine just under the header collector to keep them hot.

The 3.4 is an OBD1.5 which is a slighly upgraded version of the OBD1 in a new box.

Brian last I heard does not do flashes and doesn't think you need to. He sells a VATS bypass instead. I disagree with this because there are several things that you can tweak and need to make sure are correct such as trans type.

Marc at BCC is the best bet. I did find another place but they wanted over $100 to do it (and I don't remember their name). You can check on thirdgen.org for other places or call Moates.net to see who they recommend. There is also MegaSquirt and EBL (http://www.dynamicefi.com/). I used the EBL on a jeep and loved it. I might someday use it on my 3.4 when I have time to play with tuning.

I can't say enough about thirdgen for these engines. They did after all come out or a Camaro so they have dealt with their issues long before we started to play with them.

James


BWA


(344 posts)

Registered:
04/13/2010 08:13PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: BWA
Date: April 19, 2014 11:57AM

James there are a lot of opinions on how to do this. I am relating what I experienced with getting my 3400 converted. This EFI stuff has a steep learning curve and I am new to it. I assumed that the 94 3.4 would be very similar. I guess it is not wise to assume stuff!!
On my 3400 which is OBDII
I deleted the rear oxygen sensor and ran with one on the right header.
I ran with the internal crank sensor ( 7 teeth) and the front crank sensor (24 slots) that comes with a 94 Camaro front-cover/harmonic balancer. I did this as the programmer insisted that the engine would run better than with using the just the internal crank sensor which has 7 teeth. In Marc's conversions he runs with one crank sensor and it happens to be the internal one with 7 teeth rather than the front one that has 24 slots.
The programmer turned off all of the extraneous stuff and did a power tune on the ECU. The car runs real good and idles very smoothly. I will eventually take the car back and get it tuned on his dyno.

Cheers
Byron


DocsMG
James Spradlin

(40 posts)

Registered:
04/17/2014 01:34PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: DocsMG
Date: April 19, 2014 04:31PM

Always more than one way to skin a cat. I don't know much about the OBDII stuff. The OBDI is fairly simple. and the 1.5 is the odd ball.

Since I used the donor harness I kept all the sensors except the EGR only because it is not easy to hook up with headers and the factory one was off balanced on the SFI intake making one side hotter.



BMC
Brian Mc Cullough
Forest Lake, Minnesota, USA
(383 posts)

Registered:
10/30/2007 02:27AM

Main British Car:
1980 MGB '95 3.4L 'L32' SFI V6, GM V6T5 & 3.42 Limi

authors avatar
Re: Need help 3.4 sfi questions
Posted by: BMC
Date: May 06, 2014 12:57AM

Hi John,

I have little time and usually spend it at the MG Experience Engine Conversions forum answering questions there plus email and telephone. Love this site but only have so much time in a day to answer questions for free if we want to continue offering bits for the conversions along with our British car Restorations! I come here as often as I can...

Anyways, the 3.4L items we offer are direct fit and built specifically for the L32 3.4L RWD V6. Marc has some nice parts but they are not directed at these engines. The harnesses they offer for instance, although I do not doubt that they are nice are unfinished and unsized. Ours are exact to these engines. I do not mean to tear them down as we have used a number of their machined items and find that they do really nice work. I am saying ours were built specific for Both the 3.4L L32 V6 engine AND the MGB/Lucas wiring- a very nice transition and easy installation.

We now offer PCM tuning but I have said for 15+ years, these PCMs do not really require tuning, only shutting the VATS off. Try that with an OBD I or OBD II. You cannot- they both red lots of redirecting thus there are far more people that will work with those because they require it.

If you can call me, we can discuss many items that you have probably not even considered as of yet. There are a number of items you should know about before you start and there are pieces that we do not offer but will turn your 3.4L powered MGB into a world class build.

-BMC.


DocsMG
James Spradlin

(40 posts)

Registered:
04/17/2014 01:34PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: DocsMG
Date: May 06, 2014 09:02AM

Awesome to hear Brian. How much are you charging to do basic cals on the ECM? I've been toying with the idea of data logging mine and getting a spare to play with tuning, but I don't want to spend the money on flash equipment.


wspohn
bill spohn

(31 posts)

Registered:
10/23/2007 09:14AM

Main British Car:


authors avatar
Re: Need help 3.4 sfi questions
Posted by: wspohn
Date: May 21, 2014 05:06PM

Because I am in Canada and didn't want to be shipping the whole ECM across the border to het it reflashed repeatedly until we honed in on the final tune, I just used an OBD1 1988 ECM that was chippable.

We just used the one crank position sensor and lost the SFI (sequential injector firing) as a result, but the batch firing works just as well (I believe the SFI switches to batch firing at higher RPM anyway). The earlier ECM also takes care of any VCC issues etc.


DocsMG
James Spradlin

(40 posts)

Registered:
04/17/2014 01:34PM

Main British Car:


Re: Need help 3.4 sfi questions
Posted by: DocsMG
Date: May 22, 2014 09:01AM

Bill, how are you firing the plugs?


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