Re Map

Mon Sep 26, 2016 8:56 pm

Hi, recently rebuilt an M20B25, left it all std except for a fast road cam from cat cams. It goes really well once above 3k and pulls really clean and hard up to rev limiter however idle is not great as is expected. Anyone know of a worthy place that may be able to remap the std ecu to make it run a little smoother low down? Loads of places offers chips but I'd like someone that can listen to it, maybe drive it and say yeah we need to do this or this or no can't do anything! Help appreciated! North West.

Mon Sep 26, 2016 9:01 pm

A fast road cam will by nature always give a rather lumpy idle.

Best you can do is ensure the ICV and throttle position switch (TPS) are clean and working properly and that the engine mount rubbers are in good condition, to help absorb any vibration.

http://www.e30zone.net/e30zonewiki/inde ... ion_Switch

What is your current idle speed? Most M20B25s have an idle speed of around 700-900rpm.

I can provide a chip, as used on the Alpina C2 2.5, that gives a slightly higher idle speed which may help...

Tue Sep 27, 2016 7:59 am

Cheers for that, will double check they are good before I go any further, idle speed is around 800, I just adjusted it up slightly with the throttle cable stop screw but I suppose that upsets the TPS?

Tue Sep 27, 2016 8:29 am

it does!

Paul

Tue Sep 27, 2016 9:59 am

First of all, put the throttle stop back to exactly where it was. This adjustment is factory preset, and is NOT anything to do with setting idle speed - this is not a 1960's Morris 1000.
If you feel you need a slightly higher idle speed than standard, connect an ignition switched 12 volt source to the purple/grey wire in a small plug and socket on the engine loom, about three inches from the engine ECU plug.