Fuel Injecting the Sprint

[ham204]

Any thoughts on this:

http://www.ebay.com/itm/172539252818?ul_noapp=true

[SprintMWU773V]

Later this year you'll be able to get some lookalike SU carbs from Jenvey but inside they contain fuel injectors. There's already a Weber set available, they look very convincing. Not cheap but do look very neat, annoyingly though Jenvey only make and sell throttle bodies and they don't seem to supply he control modules or any sensors. I like the idea of fuel injecting a Sprint but I'd want to do it extremely neatly, a lot of conversions I've seen look very messy.

[sprint95m]

That SU conversion will help a bit with controlling the emissions, but that is all really.
You will be limited by the design of the inlet manifold.

Ideally you want individual runners (inlet tubes), each of the same length.

Weber do an EFI inlet manifold for a Sprint.
You then choose your throttle body (or bodies), plenum, ECU, etc,etc


Building a fuel injected Sprint is something that appeals to me.
I have a mark 2 Ford Focus 2 litre, which produces a claimed 145BHP. It weighs nearly 400KG more than a Sprint
but is faster, has better acceleration for overtaking and is about 50% more fuel efficient. It has instant throttle response in any gear too.
If I was to do a Sprint, I would go further and convert to a Ford T9 gearbox, Stewart electric coolant pump, lightweight alternator, etc.


Have a look here for a beginners' guide into D.I.Y. EFI
http://sideways-technologies.co.uk/foru ... efi-guide/




Ian.

[cliftyhanger]

The idea of a twin throttle body setup on a 4 cylinder car is all a bit (lot) of a bodge.
And for why? so it looks original despite it obviously not being?
If EFi is a goal, then best to avoid as many compromises as possible, and either use a single throttle body and plenium, or individual throttle bodies.

No reason if you budget allows to not use a pair of Jenveys on a weber inlet? look similar to the weber carbs but tidier, you can use DCOE type air filters, the lot. And the huge advantage of one injector per cylinder, which is pretty essential to get EFi to work properly. There is a reason the early single injector EFi systems were not used for long......

On my current engine build (st170 into a spitfire) I am using bike ITB's, just need a suitable inlet manifold flange with ipes welded to it to attach the ITB's. Others have had very good results, very similar to jenveys but at a fraction of the costs. More effort required though.

As to believing anybody who says itis all easy, that is nonsense unless you are experienced. Mapping is best left to those who know what they are doing, and that usually means a trip to the rolling road.

[tony g]

Could use carb manifold with hidden injector bosses welded underneath the runners and hidden loom. Pair of dummy carbs with throttle plates but no fuel looks original.
Or put a modern inlet manifold on a custom adaptor plate like I'm doing

Tony

[Galileo]

Coincidently I was only reading this post about tuning the runner lengths for the right power curve on an injected system last night. Reason I was looking is because the runners on my 2L ABF engined MK3 Golf (a detuned 150bhp so as to not affect VR6 sales) are amazingly long and I was curious as to why. http://www.emeraldm3d.com/articles/emr- ... th-intake/

[bluetriumphsteve]

Patton Machine has been making 'hidden' Pi systems in SU carbs for some time now, although his stuff is mainly aimed at TR's he does do custom things aswell, so a Sprint could probally be done. Take a look at his website. I toyed with the idea of doing it to my 1850HL

http://www.pattonmachine.com/TBI-Components.htm

Cheers

Steve

[Len Hughes]

In this months Classics Monthly p14 Burlen have a twin SU setup with internal injectors that look neat, no idea on price though.

[cliftyhanger]

But any EFi system where cylinders share an injector will be a poor compromise.
Add that to the fact that fundamentally cylinders 1+2, and 3+4 sharing a carb/intake is also not ideal, you will end up with a disappointing EFi setup that won't develop the expected power or I suspect economy that should be available. On top of that it seems they use the distributor somehow for timing? not great, should be off the crank to give greater precision.

I would politely suggest either keep the car on carbs OR do a proper EFi conversion, don't go for a bodge/compromise.

[tinweevil]

'Fit & forget' with all those sensors and electronics? Come on. I'm not saying it isn't better when it is working but the list of things in that (admirably comprehensive) list of sensors that will leave you stranded when, not if, they break is extensive. Do it by all means but do it with eyes open.

[Carledo]

'Fit & forget' with all those sensors and electronics? Come on. I'm not saying it isn't better when it is working but the list of things in that (admirably comprehensive) list of sensors that will leave you stranded when, not if, they break is extensive. Do it by all means but do it with eyes open.

I don't think anyone is claiming EFi, or rather Electronic Engine Management, is fit and forget! But it is many times more reliable and efficient than a pair of SUs and a points distributor and is effectively maintainence free once set up. Sure you will get the odd sensor failure over the course of a couple of hundred thousand miles, nothing lasts forever! And you still have to change the spark plugs (and maybe the leads) occasionally. All these systems can be set up for diagnostic to determine what has failed and only one or two sensors will stop the engine completely if they fail. It would be no harder to carry spares of these in the glovebox than the set of points and a condenser, that the more prudent (or paranoid) of us carry for standard systems.

For my own part, the only spare I routinely carry for the Bosch Motronic system on the Carledo is the fuel pump relay, it's the only bit i've ever had to replace on one of my own Motronic fitted Vauxhalls in 20 years and many, many thousands of trouble free miles. And that only happened once!

Steve

[cliftyhanger]

I think the only absolutely essential sensor is the crank position sensor.
My engine will use a cam position sensor too, but that wouldn't be needed on a dolly engine, or indeed most others.
Apart from that it has 2 temp sensors (but will run without either) one being the equivalent of a choke, the other fine tuning mixture according to air temp (rather more successfully than waxstats!) And throttle position or MAP, again the equivalent to vacuum advance.

I guess some will fit lambda sensors, again so the mixture can be fine tuned as you drive. But all that stuff is super reliable these days. Only failure I have ever had was a poor crank position connection. And one car the coilpack went down on 1 cylinder at 120k.

That has got to be in best part of 500k of driving. On my triumphs mileage is rather less, and component failure rather higher...

[Brynk]

If you lads wants to run EFI, a cheap way for DIY minded; Volvo B230 has detachable loom and can be had at most junkyards.

Then you need to fab a fuel Return and a special plenum to fit on the manifold, and make a flange for the throttlebody. You can get a injector drill online, and custom fuel rails can be had too.

It's a Bosch 2.2 system, and Bosch already made it to fit a multitude of cars, so can you.
There will be some fitteling with wires, and the injectors can be replaced with smaller ones, depending on horsepower goal.
A adjustable box would also be very helpful. And can. It can be had for resneable price on the aftermarked or Second hand.

I know it's not British, but that doesn't make it wrong.

I know no other cars that run a detachable wire loom. But there might be some.

[Carledo]

The Carlton 2.0ltr (Omega A) and Cavalier 2.0ltr (Vectra A) also have a standalone engine management loom which requires just 5 wires connecting into the car to make it run. These being permanent live, ignition live, earth, rev counter feed and fuel pump feed. everything else is contained within the loom. There is also provision in the loom to feed a diagnostic plug.There is a secondary and much smaller independent loom that takes care of alternator, starter and temperature guage wiring but this is so simple you could make it yourself to suit your car.

This is the Bosch Motronic system that I have used in the Carledo and have found it both simple and foolproof to install and utterly reliable in service. Even going months between startups didn't faze it back in the days when it was only taxed 6 months of the year. Nowadays it's taxed all year round cos it's free so it gets used pretty regularly. And being designed for a 2.0ltr 130bhp car, the system should suit a Sprint pretty well. It's also relatively simple (so i'm told) to adapt the ECU for owner mapping, this is the next thing on my agenda for the car.

Steve

[Brynk]

Good point, Steve. Didn't know the carlton/cavalier was the same.

That is good info! So the Omega and vectras is actually good for something
Pure joy