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MG MGB GT V8 Factory Originals Technical - 3.4 V6 Camaro swap EFI questions - long

Okay, parts gathering phase moving along. I got a 95 Camaro engine, 3.4 60 degree V6 with Sequential Fuel Injection (SFI). Now I've got alot of questions that I suspect many of us will face if we go the OEM injection/ignition route.

1) fuel pump. I need a new tank anyway since my MG tank smells ripe. I figure get new tank, cut hole in top and drop in the combination sender/fuel pump from the Camaro. I always wanted to weld a gas tank - and lengthen or shorten the fuel pickups. Is it possible to swap in the Camaro tank (doubt it)? What about exhaust system routing by the tank - single or dual pipes? The alternative seems to be keep the piece of manure SU pump and use it to feed an external injection pump. Any reccomendations?? Fuel Cell $$$?
2) Lambda or O2 sensors are mounted in both cast exhaust manifolds. Should the header kits get twin bungs welded in to accept the 02 sensors. These are kind of important because they measure oxygen content in the exhaust and give a signal to the ECU about mixture strength. Too much O2 means not enough fuel and the engine is running lean (or misfiring). Too little 02 means the mixture is rich. Prior to warmup the engine runs without using the O2 signal in closed loop (or was that open loop) mode, once they are up to operating temperature, the ECU uses the 02 signal which allows the mixture to become more adaptive to actual conditions rather than running some pre-defined map. How do I keep them? Where do we put them? Do I need to keep both? I imagine that the two sensor signals are AVERAGED to compute mixture. If they are ADDED together, it sounds like they both need to be kept. Did the Camaro have yet a third 02 sensor behind the CAT??

3) Electronically controlled EGR stuff. The right hand exhaust manifold feeds an electronically controlled Exhaust Gas Recirculation valve. It would be nice to be an environmentally conscious citizen and keep this thing, but what if it can't be done? I know the ECU controls it, but will the computer care (and cause the engine to run badly) if it is disconnected?? Do you just put blanking plates on either side??

4) Charcoal cannister and purge control valve?? I still don't know what the hell this stuff does nor do I own them. I think I'm also misssing the electric air pump. Do I need them. Will their absence adversely effect performance?? Can they be bypassed or can the computer be fooled into thinking they are connected without harm??

5) I don't suppose the stock manifolds and headers can be used. This would solve the 02 sensor and EGR problems. Both could be left alone right where they are. The right pipe runs under the front of the engine by a relief in the oil pan. Is that the problem? Is crossmember clearance an issue(chrome bumper 72 BGT)? Could the crossmember be notched and then reinforced father forward. I've got a full spool of wire in the MIG, and access to a cheap spare crossmember guinea pig, so if it can be done, I'd like to give it a go.

6)I don't suppose the AC compressor can be kept. Low on the right front side. How cool would that be - no pun intended to cobble up an A/C syetem to boot.

7)Speedo sensor. I got a Automatic trans, but will be switching to a manual box from a V6 Camaro (yes, I know the gearing will be very low). Will the ECU need to be swithced to a manual box version?? The present computer appears to be 2 separate units piggy backed together ( 1 engine & 1 Tranny??) Does the computer need an accurate speed signal (electronic speedo) to do the voo-doo it do?

8) What else have I forgotten. Relays relays relays... yikers?

9) How do I hot wire this bad boy?

Brian Corrigan
Forest Hills, New York
72 Bgt in Rust Never Sleeps Red
Brian Corrigan

Go to this website:

Email Brian too. I have been considering this swap and have been in correspondence with Brian for a while. He can provide you with most of the information.


My friend you just bit off a big chunk. Expect to be chewing on it for awhile. Can be done though if you're persistant enough. Best advice I can give you is to do a search for diy_efi and use the gmecu link. These guys are really into this stuff, building their own controllers and such. You've asked quite a few difficult questions. Might want to take them one at a time, get more answers that way. But...

Speedo shops have speedo sensors. About $100
AC, anything can be done. May take serious resculpturing though.
Learn to gas weld and build your headers.
EGR, canister, air pump, can go either way, it may affect the need for tweaking the ecu.
2 layer, probably controller and drivers, or FI and Ign.
Go wideband on the o2 sensors, at the collectors.
Pump/tank, many options. New tank with baffles added to form a pump well is the cleanest, but a smaller tank in the spare battery well is a decent option if done right. Don't throw away that Lucas pump just yet.
Jim Blackwood

A trick that was suggested on this board may be handy: for the return line, rather than weld the tank, use an early tank and a later sending unit. The early tank has the outlet on the tank body. The late sender has the outlet bundled with the sending gear. Surge tanks seem to be the consensus for EFI.

Painless wiring can take care of most of your wire problems. They may seem a bit expensive at first, but are worth the $$ if you time is worth anything at all.

The ac will fit.May take a new braket, but it will work. See "killer"

You are gonna have to make headers. Try fitting them backwards; reversed side to side. This may give you some options for routing.Saw one at a show. Looked funny but was cheap.

The computer does need a speed signal, regarless of wether you hook it up to a speedo or not. I hope you got most of the sensors with the donor, as buying them one at a time gets expensive.


In regaurds to Petes response...
No, you will not need a speed sensor. If you are using the 4L60-E automatic, then you will need the VSS installed as the PCM (not ECU) needs the speed signal for transmission shift points.
The PCM will also give you better fuel economy if it is hooked up, but will limit your top speed.

I have driven my first 3.4L SFI conversion with NO problems and it does not have a VSS installed. My first 3.4L SFI conversion is in my Chevy S10 and I get 22 MPG..............

AT 90 MPH!

The owner of the 1978 MG B3.4L SFI told me he gets 26 mpg and we do not have a vss on his car. He still has the 3.909 rear end ratio, but MGB's comparably have no weight to them.. At least 700 lbs lighter then a Camaro...

BTW: If an MG B with a 3.4L engine installed in it weighs 700 Lbs. lighter then a V6 Camaro, the MG B has headders, a good intake, and a chip (many other goody options avalible too) Why would some people ever consider a 350ci? Some people don't understand power to weight ratio, handling capabilities and other items such as that...
Brian Mc Cullough

Some people like 8's and the seemingly limitless amount of go fast parts available for them. So youve got a 190 horse V6; whats better than a 6, why 8 of course. 200 horse outa a very tricked and expensive 6 or 400 out of a mildly modified 8? Power to weight? Ill take the 8.
Jarrod Hills

Brian, There is a guy in Ohio named Cooper( last name) that built a 350 small block yellow GT and the present owner lives south of Dayton and from what was said about it a car show was was this. " Yes it is a very fast car but is very hard to control if and when you can get it to stick and it is verrrrrry scary in the turns." Apparently it acts like a dart and heads for the ditches in the turns. My question is how much fun is a car that could kill you? People don't seem to realize that a light weight car doesn't need tons of torque for high performance. By the way, the national NHRA record for an import car powered by a 97 cubic inch engine. This car runs in the upper seven's in the 1/4 mile. Other import 4 cylinders are running in the eights and nines. Ryan Falconer builds a 3.0 liter version of the 3.4 GM V6 that puts out over 700 HP. I'm with you Brian. An MGB that is fast, safe, modern and very dependable is my choice and the V6's are not tricked at all, it is perfectly stock and still puts out 200 HP. Any stock 215 c.u. Buick version that is in a MGB cannot compete with the transverse 3.4 in any which way, whatever, period. To compete with reliabilty would cost hundreds of dollars at the engine builders shop, I know because I have been there , done that. I love the V8 but it should not be the choice for the performance enthusiasts in modern times. It doesn't add value to the car either as some would believe. Dann
Dann Wade

Thanks for your collective input. I certainly didn't want to start a debate about which engine is THE right one. That is a personal choice - there is no one answer.

I went with the 3.4 V6 because it appears to be a lot less work than the Rover 8. Also, it is more readily available in the U.S. Since the 3.4 is a 60 degree V and not a 90, the headers can exit under the firewall rather than cutting holes in the fenderwells. With my chrome bumper GT, the steering doesn't have to be modified with either an addtional Borgeson universal joint or newer column and bulkhead mods which would be the case if I went with a 90 degree block (6 or 8). A little massaging (sledgehammer) work might be required, but no cutting, welding, cross member swaps, or extensive fabricating. Bill Guzman makes a kit for bolt-up engine and tranny mounts as well as headers. I will have to lop off the old engine mounts, but that's about it. I submit that any engine which is alot heavier, regardless of power, would destroy the nature and overall balance of the car- but if you are looking for a straight line point and shoot weapon, an MG might be a real unique big block sleeper.

If you are into challenges, this swap can be as easy or difficult as you like, what with GM's love of acronyms, you've got the PCM -(Powertrain Control Module) which sports SFI (Sequential Fuel Injection) and DIS (Direct Ignition System - no distributor- crank and cam triggers instead). The Brain has a programmable Flash EEProm which means that armed with a PC, software, cable adapter, and plenty of patience, you can reprogram the whole damn thing (over and over and over again).

BTW, ther are two Brians on this thread, I'm the one who started it and know relatively little, and then there is Brian Mc Cullough who knows a great deal about this swap.

Safety Fast(er)!

Brian Corrigan

This thread was discussed between 29/10/2001 and 07/11/2001

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