mk1b ecu questions

[charlie]

will the std ecu run as ignition only?
if it will what parameters will need to be used?.thanks

[aw11rally]

It can be done, not sure it works without mods though.

Our rally car was using the original mk1a ECU when on twin 45 webers. I've not got a clue how to do it. Personally I'd go for a megajolt or similar for fully programmable ignition control.

[charlie]

Mmm.was hoping to start with the std ecu to run things while i got a decent ecu,otherwise i will leave the std injection system on.

[aw11rally]

The standard ecu will run carbs, it may only give static timing though. With everything else removed I suspect bridging the diagnostic ports t1 and e1???? Would get a car with running at least.

Not ideal.

[PW@Woodsport]

I don't see the point.

[MartG]

I don't see the point.

This - unless you're fitting carbs or ITBs or are doing other major mechanical mods to the engine there is no point replacing the stock ECU with an aftermarket one unless you just want to get rid of some money for no real gain

[charlie]

I was thinking of fitting carbs to it to get a bit more go without the expense of fitting an aftermarket ecu to it at the moment.

[LimeyMk1]

I was thinking of fitting carbs to it to get a bit more go without the expense of fitting an aftermarket ecu to it at the moment.

If you fit carbs you'll need to change the fuel pump to a low pressure unit if you use their fueling system.

Best bet is to use the stock injector set up (maybe with slightly bigger injectors) and just use the carb bodies as throttle control.

No idea how well the stock ECU would cope with an ITB/Carb setup as it needs a MAP input. This can be achieved by taking lines off each inlet (just after the ITB/carb to a vacuum 'log' (e.g: http://www.goldeneaglemfg.com/index.php ... Path=78_90 ). I get a rock solid vacuum reading off my ITBs at idle and when revved, but then there are 6 of them.

Then there's the TPS input, you will need to ensure the TPS on the carbs or ITBs has the same output as the stock one or adapt the stock one to fit.

After all the faffing to get it right you'd be better off getting a megasquirt ECU (or similar) and calibrate the ECU to the sensors you have. You don't need to spend megabucks on an ECU for the 4AGE.

[PW@Woodsport]

Agree with everything chris said, plus when it's all done you'll be lucky to see any serious gain, it's just not worth it in my opinion, sound good though!

[charlie]

Thanks limey thats the answer i wanted.not sure now what to do.interesting though paul that you say itb or carbs dont make much difference.another question then will the original injection setup with aftermarket ecu work well with decent lift/duration cams or will it be restrictive?.

[LimeyMk1]

The injectors should be good for a few more ponies, but fortunately there are plenty of injectors out there you can replace them with if you want more fuel. (e.g. Supra 440cc but you probably won't want any that big)

Any idea what you have at the moment? There are at least 2 different injectors used on the 4AGE in the MK1.

Carbs/ITBs will make a difference if used in conjunction with other engine mods (cams, high comp pistons etc) but then you're getting into an expensive operation.

Have a look here:

http://www.imoc.co.uk/forums/viewtopic.php?t=131284

and here:

http://www.imoc.co.uk/forums/viewtopic.php?t=129987

For some ideas.

What is your target for the car?

[charlie]

Hi limey,im building a rally/track car.just want more go.my basic thoughts were to fit parts to it,eg cams ,ecu as an on going thing but need everything to work together,eg no point putting hot cams in if the std injection/ecu wont run it,hence the thought of running the original ecu as ignition only then i could fit some hotter cams next then the standalone ecu.

[charlie]

No idea what injectors are in at the mo but the car is an 1989 car.

[gon]

If you leave all the other sensors installed and put some resistors instead of the injectors ( measure injector resistance and calculate resistor size) the ECU should give you an half decent map to run carbs without throwing any errors.

On the other hand, if you try to run the original injectors and ecu on itb/carbs it will just not work and I would advise against it.

[aw11rally]

If you want a good reliable power gain then I'd recommend saving up and doing a proper head build to suit your desired cam. These engines already have the ability to rev, the head is where the power is at. Spending the money on a decent head build will really pay dividends. Bike carbs and a distributerless ignition system will provide all the fuel and sparks that you need.

I really don't think trying to stick with the standard ECU is the way to go.

[charlie]

Thanks guys.lots of info there.

[elbon50]

I'm interested in this

Do keep us informed re your future plans Charlie