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MG MGB GT V8 Factory Originals Technical - after market fuel injection

my convertion is a rover v-8 from a 1980 sd1 fuel injected. I have all parts of the system from ECU to relays gas tank etc, etc. I would like to use these for the economic part of the ecuation, but for what i have read this is an old system and living in idaho these cars you dont find in every other corner and land rover dealers (1) dont even want to talk to you if your car is not at least a 1988 model.
my question is: has anybody experienced the TBI fuel injection convertion or holley projection fuel injection, or edelbrock? it seems to me it is much user friedly and is also tunable. any help out there?
thanks romney

I also have a similar problem except no ECU or wiring harness (small engine fire in host car). I was also hoping to see that someone has retrofitted another ECU besides the Rover unit.
Ozzie Pillon

I went down this path a couple of months ago because it seemed fuel injection was the easiest way to get my car emmissions legal. Here's what I found...

I think the Edelbrock is the same as the Accel system, and I priced the components out at around $1300 if I had a suitable manifold and injectors with the correct impedence. That wasn't the end of the money because there wasn't any maps available for the 3.5L/215, and the box would have to have the maps established on a chassis dyno. That would about double the price. They have specialty shops called 'EMICs' that they recommend you have do the work. The results are good, but quite expensive. Otherwise you have to try and get it close with a laptop computer in your car as you drive. ( I have a friend who used the Accel box on an automotive engine installation on an experimental airplane to great effect; it can be done on a car)

The Holly system seemed to have a pretty poor reputation and was a throttle body type system(wet runner) to boot. People I talked to seemed to have drivability problems but it was more reasonably priced. I was also told the Holly systems had been seen at automotive swapmeets for around $200 from people frustrated with trying to get them to work right. (Ive since seen ads for a new generation system that I don't know anything about, but they have a website)

The next option I investigated was to use the Rover intake and plenum (modified to fit under the hood) with aftermarket fuel injection components. The system that looked the most interesting was one produced by 'Simple Digital Injection' for about $600. The computer's maps were programmed by a simple interface box that you could program from the drivers seat once you got the motor to run. They made no claims for being able to get it to pass emmissions, and oxygen sensor was an option, but this looked like a pretty robust system. If you want to spend even more money, there are other boxes out there from Halltech and others, but I think that by the time you bought the box, PC interface cable/software, harness, regulator, fuel pump and injectors/rail you would still have significant investment.

Which leads me to the conclusion I reached after looking at all these system options; keep the system you got off of the SD-1 or source a fuel injection system from a later model Rover with the same displacement (read fuel map) as your engine.

The TR-8 guys have had this earlier SD1 system now for 20 years and know all the workarounds to get the system to work. Only two components cannot be sourced off of other cars is the ECU itself and the airflow meter. The ECU can be exhanged, but the Triumph guys have developed repairs that most people can do themselves that involves fixing cold joints resulting from excess heat/cycling. The airflow meter is available in Europe, (very expensive) but several firms in the states rebuild them for around $200. Everything else was used on something else from Jags, to VWs to Alfas. Wiring diagrams, interchange guides and box repair instructions are available on the web. The XJ6 Jag fuel pump and filter work well: most of the system is Bosch when you peel the Lucas stickers off.

I have to confess that a big part of my motivation was to pass emmissions at the lowest cost and least sacrifice of performance, and it seemed liked this system would best meet those two goals. When I upgrade, I'll most likely find the hotwire system of a later model Rover, shorten the plenum and stacks to fit under the hood and use the factory system. RPI Engineering has several performance upgrades for this system.

Whatever your choice, I strongly recommend Probst's book on Bosch Fuel Injection, available from

If any of this makes any sense to you and you'd like to investigate further, I'd be pleased to provide hyperlinks to the websites I mentioned,


Romney and Ozzie,
I have the same problem that I have a 1980 Rover engine with FI. Do you guys have what they call the Federal fuel injection? The plenum looks flat and very suitable to fit under the MGB hood.
I have all the parts but not the ECU and wiring harness. Mybe a hint from our friend Roger Tamworth can get us on the way. For now, I am driving with the Carter AFB 400cfm mounted. It works well but will be safe when the emission laws start acting up.
Is there an ECU that can substitute the original one? Maybe a Bosch unit from a German car?Or mwhat about contacting Bosch for more info?
werner van clapdurp

I have been looking into this myself and have come across an Australian company producing engine managemant systems.

The allow you to download all there mapping software to play with, and its very user friendly. They even have mapps to download for a standard Rangerover 3.5 and a bored out 4.3 litre engine.

Having spoken briefly to the UK supplier a basic fuel management system, including ECU, wiring loom and software for the standard Rover FI is 500 plus VAT. This system disgards the any airmeters, releasing the ristriction there, and he was quoting me up to 20% performance increases on standard setups.

This would be especially good for anyone with damaged looms or blown ECU's as the economics would be offset conciderablly.

They also do combined ignition management systems, so the 4.6 gems FI would be an ideal candidate,so as to keep the distributerless system

Nick Smallwood

Phil in Phoenix:
wow! you really did your homework on this one, it sure makes mi decision easier. I will stick with the sd-1 fuel injection, because, that is what i have. And since i paid close to nothing for the whole working car that had been abandoned by a service man going overseas, the cost of the whole convertion is going to be managable.
Thank you for the info.

Werner, yes I have the federal fuel injection complete. It used to be in a 1980 SD-1 that a service man had abandoned in a recycling yard, Here in Idaho cars newer than 1984 are required to pass smog test. But i want to be ready when big brother forces old cars to submit to the sniffer test.


The Federal/Australian spec is the two piece inlet assembly with a flat topped triangulated shaped plenum. This is fixed by 8 bolts through to the inlet below. This is the pattern of system I first used on MG's in 1983 and it works just fine. Being that the overall height is several inches lower than the later 3 piece Vitesse/Range Rover casting it fits under the standard bonnets. (Sorry hoods!) This assumes that the factory style engien mounts are used toi keep the engine at the same relative height.

There are very few differences between the Federal set up and the later Vitesse and Range Rover systems. This means that 95% of parts except castings interchange with no problem. The main differences being the double relay reverting to a pair of relays and a separate diode pack and the throttle pot changing from a large three point fixing to a small two point. Internal functions of both are the same!

The main advantage is that any later injected Range Rover Airflow Meter system ECU will clip straight in and work brilliantly. Usually much better than the original SD1/TR8 versions. Also the wiring harness is the same pattern and will interchange, but will have different lengths. Only the differences in the parts I mention will show up and the later harness has more common type plugs so the changes are not difficult to do.

The injection system on the cover of 'How to give your MGB V8 power' is my old system that I have sold on and which is replaced by Hot Wire. In fact there are pictures of my system and car in both this and Hardcastle's Tuning the Rover V8 book'.

It is worth noting that I have removed a couple of 'modified' ECU's from different cars. One was a bored stroked 4.3 litre unit running Airflow Meter. It was flat and thirsty until I fitted a standard Rover Vitesse ECU and then it flew. Even with a standard UK spec Range Rover ECU it ran much better than with the modded ECU as did another 3.9 litre conversion.

Range Rover fuelling maps are more sensitive to fuel efficiency and emissions, but don't actually lose out in terms of power. That applies to 3.5 litre engines. Larger displacements benefit from what the chap who did the original mapping at Lucas said was 'over generous' fuelling to cope with the 300bhp spec Group A engines that were later found to be illegal!

Today in the UK finding earlier Airflow Meter system parts is very difficult as so many of the cars are history. I used to be able to find a reasonable supply of these but haven't seen any in a long time. Others I know are having similar difficulties.

The supply problems leads to the next phase of thought. This is to take advantage of aftermarket ECU's that are used instead of the original Rover ECU. At the same time dump the airflow meter and use manifold pressure sensing for airflow calculation. This will provide a usefull power bonus too.

It is also possible to use the Range Rover Airflow Meter system castings for the later Hotwire use with a little modification, but this needs the Hotwire system parts as well.

Finally if you do have a fully working Federal system then you may be interested to know that with very little modification to my 3.5 I was achieving nearly 190bhp at the rear wheels with all the advantages of injection. That makes for a reasonably rapid, yet economical, MGB.

Roger Parker

This thread was discussed between 19/02/2000 and 25/02/2000

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