SPARKY WRX

Hi,

I have just got a HKS fuel cut defender and would like to know when the FCD alters the MAP signal does that course a problem because I thought the MAP sensor was used for fueling, altering it would cause leaning out of the fueling, is this correct?

Cheers

Mark

nom

On the JECS the fuelling is, I think , mainly MAF based.
But yes - the way the FCD works is by reducing the apparent MAP to the ECU. The trick is to dial in only the absolute minimum that you need to to get the desired raise, which is minimal, and it shouldn't cause a problem.

SPARKY WRX

Cheers, whats JECS, is that an ecu, I have standard ecu on my 94 wrx

Cheers

Mark

nom

It's the ECU, yes; although I'm not sure is the one you'd have on your car, typically MAF based ECUs will base most of their fuelling on the MAF rather than the MAP

john banks

If you are playing with more boost and FCDs you will be monitoring AFR and det anyway

Yes you have a JECS ECU, MAP is a small input into the load calculation so it might lean and advance slightly.

http://www.mr2.com/ARTICLE/HKSFCDat.html

Use the setting that just gets rid of fuel cut and then 1 click more for safety margin for overboost so that you are only modifying the signal the minimum that you need to. Have a look at the Vin/out type graphs on the spreadsheet, also do a search on FCD in this forum for loads more info.

SPARKY WRX

Thanks guys,

I have an Apexi AVC-R, Dawes AFR gauge and lambda link, I Am running 0.95 bar and all seams well but was getting a bit too close to boost cut just around 1 bar. I would like to run 1 bar and push the fuel cut a bit further away, at say 1.1 bar.

So I might get away with a setting, say 10 or 11, am I correct in thinking that on the FCD 12 is low and 1 is high?

I installed the FCD last night, I used the ecu ground and took the power from the cigarette lighter and set it at about No. 2. I started the engine and the engine check light came on, I didnt have time to investigate so I disconected the FCD.

Colud the engine check light have come on because the signal the ECU was recieving, was outside the perameters for the MAP sensor.

In looking back maybe I had a too low number, maybe I should have tried 10, 11 or 12 etc.

Is this correct and can I stay within the parameters to get the boost cut figures I need without causing the check light to come on.

Thanks

Mark

john banks

which turns off when the engine is cranking, hence the CEL.

SPARKY WRX

oh!

Thanks John,

Ill put it on the ignition feed then

Mark