Small TBI with IAC for an MGB

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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EFIMGB
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Small TBI with IAC for an MGB

Post by EFIMGB »

Hello,

I need some help here I am putting EFI on an MGB that was converted to a Weber DGV downdraft carb several years ago via a pierce manifold.

So here is what I need.

I would like to locate a small throttle body that has the injectors already incorporated as well as the, TPS and IAC. It would be helpful if the TBI really is an "all inclusive package" that will eliminate me from having to make all sorts of extra things that can go wrong. It would be easier to make an adapter plate to mount it to the intake (that and the fact that the MG has siamese ports) then to try and create a new intake. I will be using the MS-II to control everything as I am also looking at adding the Ford EDIS (already have it from my early planning days). So to get this project going I need suggestions for the TBI. Keep in mind the MG is a 4 cyl 1.8l engine. Not a storming V-8.

Thanks for any help
arnold
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Post by arnold »

Hi

I use a TBI unit from a Opel Astra (Vauxhall), it is a Rochester, with a Rochester Injector.

If I were you I would look for an older type EFI car (so with no port injection yet) and with displacement / power similar to yours.
mikesb
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Post by mikesb »

There's a few of us playing with these siamesed port engines. Arnold, Werner http://home.comcast.net/~whaussmann/wmg ... ameset.htm
and me (link below).

I used one of the TBs from a Honda VT1000. I've still got one from a sunfire/cavalier that looks like it would work but I never used it.
woh
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Post by woh »

There are many throttle bodies that will work, fit, and come with the integrated fuel pressure regulator and injector. Ford, GM, VW, come to mind. They are all from the mid ‘80’s. The throttle body on my web site came from a Ford ’86-88 Taurus, ’85-87 Tempo, ’85-87 Topaz, and ’86 Sable. This is a throttle body for a 2.2-2.5L engine. A bit oversize for the MGB. I used it because it fits, it has an adjustable regulator, easy to use quick disconnect fuel lines, and it allows plumbing for fitting a Bosch Air Meter. My first and second installation were for a Bosch L-Jetronic system and required a method to route the air to an air meter before the throttle body.


I did try a ’87-90 Escort, ’87 Mercury Lynx (1.9L) throttle body. It includes an air filter mounted on top of the throttle body. This would avoid the air plumbing and makes the installation simpler and cleaner. This throttle body is correctly sized for the MGB. After fitting it, I found the clearance to the hood to be almost nonexisting. So I went back to the Tempo TBI. The escort TBI could be fitted by taking a ¼ inch off the top of the pierce manifold, and eliminating the plastic spacer. I think it is a better way to go, but will require some mods on the manifold. These Escort TBI’s are more readily available. Maybe you can talk Pierce manifold into building an EFI manifold for you. They should be getting into EFI instead of doing only Webber carbs.

Almost any TBI will work with the Megasquirt (MAP) computer. Getting it to fit and building an adapter will be the most challenging. Make sure to get the air ‘piping’ from the donor car for the TBI. From my experience, the easiest and cleanest with a MAP sensor ECU will be to adapt the Ford Escort TBI. I did not see any, but there may be a TBI out there that fits the webber bolt pattern. If you see something like that please let me know.



The ‘80MGB has a single carb. Do you still have the original manifold installed? You might try just using that for starters and then go to the Pierce manifold once you have it working. The original manifold allows for a lot more clearance than the Pierce.
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