how to tune my 944 for optimal fuel efficiency

[m.zantides]

Hey guys

Does any one know how to properly tune a 1986 2.5 base 944? I need to get the fuel to air mix right, because I am finding that my car is really off right now.

Thanks guys

 

[robwright]

Firstly a bloody good service. All filters, oil, plugs. If that doesn't do the trick then I would look at the HT leads and dizzy cap. After that I would start looking at cleaning the Air Flow Meter or even replacing it if the problem is still there. What do you mean by off? There is also injectors as well. They are not cheap new but you could have them cleaned. It really depends how much money you want to spend.

 

[m.zantides]

Hey Rob,

Well the cars recently has a service, and I have had the MAS cleaned. I was thinking it might be the injectors. I need to remove one and have it checked for dirt.
As for off, well I find that she is consuming a large amount of fuel, and that her acceleration if off very laggy and I find that the RPM's wont let me load the engine beyond 5000 rpm.

Its hard to really describe, the problem fully.

 

[robwright]

What do you mean by had the MAS cleaned ???

 

[m.zantides]

My mechanic used a cleaning compound to clean any dirt off the mass air flow sensor. But I have a feeling that they didn't bother regulating the C0 correctly. And I was wondering how I can regulate and tune the air/fuel mix.

 

[robwright]

Is your car modified? If not it doesn't have a Mass Air Flow sensor. It has an Air Flow Meter. Two very different things. I think it is possible to adjust the idle mixture on a NA 2.5 engine. Have you had a look on www.clarks-garage.com ? Look at the troubleshooting section it may help. Into the equation could also be the Fuel Pressure Regulator or indeed the fuel pump.

 

[m.zantides]

Thanks Rob, I am sorry I got myself mixed up and on the name of the sensor. No the car isn't modified at all, I want to keep mine as pure as possible. I will take a look at the trouble shooting section. Thanks for all your help.

If I have any issues I will post it.

 

[ukmastiff]

One thing I did learn with my last 944 is how easily a mechanic , or in this case tuning specialist ( in his flamin dreams) can ruin a MAF. As far as I know they arent really meant to be opened and fiddled with despite the fact that instructions to do this are on the web. I only mention it to say be very weary of fiddling with that item of kit.
Maybe a carefull clean is acceptable if you ask someone who knows better than me
( lots of folk that is) but it was described to me as a factory sealed and very sensitive instrument. A new (recon) one transformed my car. If you really cant get it running right its amazing how quickly a 'real' specialist will find the fault at not to high a cost.

Good luck

Mas

 

[Northern924]

You can't tune the 2.5l in the old fashioned way like you would say an MG or for that matter a 924, everything is electronically controlled.

Any mechanic who doesn't know that shouldn't be working on your car, as has already been said new parts is about all you can do, but also check that the DME is working properly and that the reference sensors are responding correctly

 

[944 man]

My first guess on an old car, would be that either an incorrect DME (ECU) or airflow meter had been substituted. Itll run but your mpg figures will fall.

Promax's site has Bosch and Porsche part numbers and pairings.

 

[robwright]

ORIGINAL: 944 man
Promax's site has Bosch and Porsche part numbers and pairings.

Where is that mate? I have looked on Promax but can't find it. I need the Bosch part number for a turbo AFM.

 

[pegasus]

Hi Rob,click on technical,and then ecu information,hope this helps John.

 

[944 man]

I cant link to it for you, because its a framed page. Promax homepage > Information - Technical on the left hand menu heading > ECU Number Listing, second from the bottom on the right hand column. Unfortunately any attempts to link to itll just retun a 'www.promaxmotorsport.com' front page.


Simon