S40 ignition idle control Issues

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
k-jet16v
Posts: 3
Joined: Tue May 01, 2018 6:01 pm
ECU Model: S40 Pro
Distributor: stealth racing
Firmware Version: 73

S40 ignition idle control Issues

Post by k-jet16v »

Hi there guys, I've looked around for info online and on DTA's site and can't seem to find the info I'm after, I can not seem to be able to get my idle ignition control to work, tried different settings and no joy.
The car is a Golf on K-Jet
ECU is S40 ignition only unit, inputs are air/water temp and map base load with no TPS.
Can the idle control work without a TPS on this ECU?
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: S40 ignition idle control Issues

Post by Rob Stevens »

No won't work as it will never know when its trying to idle, you could try playing with the default tps value on failure but I think you will draw a blank. Fit a TPS ?

However a good way of getting a strong idle is to have ignition timing of say 15 degrees at 1000rpm and 2 degrees at 1500rpm the engine will just sit between these 2 points. but still best to fit a TPS
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: S40 ignition idle control Issues

Post by Alex DTA »

What Rob says.

You can also alter the map rows to have a couple of close RPM values to give a bit more idle control, but that's a bit of a sledge hammer approach.

Fitting a TPS is the best solution.
k-jet16v
Posts: 3
Joined: Tue May 01, 2018 6:01 pm
ECU Model: S40 Pro
Distributor: stealth racing
Firmware Version: 73

Re: S40 ignition idle control Issues

Post by k-jet16v »

Thanks for the reply Rob, ok that answers that then. :-( I've restored the car and really wanted to keep it looking as standard as possible from the outside, bolting up a TPS on to the standard throttle body will look pony! I've done a good job of of warm idle 90%, it's cold idle where I have a issue. I did a 'work around' with the water temp compensation adding global ignition which isn't ideal.
My next step was to do as you say Rob and turn default failure TPS valve to '0"
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: S40 ignition idle control Issues

Post by Alex DTA »

I have done what Rob mentioned on my 9A turbo (so 2L KR), and it works very well.
Starts on the key from cold, and idles well.
Mr Drew
Posts: 62
Joined: Mon Apr 09, 2012 11:08 am
ECU Model: S80 Pro
Firmware Version: 62

Re: S40 ignition idle control Issues

Post by Mr Drew »

It's a long time since I saw a k jetronic system but didn't they have a switch on the throttle body to detect a closed throttle? A couple of resistors could be added to the wiring to give a valid signal and it would still look OEM.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: S40 ignition idle control Issues

Post by stevieturbo »

Fit a TPS sensor at the pedal then...not ideal, but still functional.
k-jet16v
Posts: 3
Joined: Tue May 01, 2018 6:01 pm
ECU Model: S40 Pro
Distributor: stealth racing
Firmware Version: 73

Re: S40 ignition idle control Issues

Post by k-jet16v »

stevieturbo wrote:Fit a TPS sensor at the pedal then...not ideal, but still functional.
Good idea, been looking at different sensors and mounting opinions.

Mr Drew wrote:It's a long time since I saw a k jetronic system but didn't they have a switch on the throttle body to detect a closed throttle? A couple of resistors could be added to the wiring to give a valid signal and it would still look OEM.

yes there is a close detect switch on my K-Jet throttle body, that sounds like a nice easy work around to the TPS.

Thank you for all the replies guys!

Here's a few pics of the motor.Image[/url]ImageImage
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: S40 ignition idle control Issues

Post by stevieturbo »

Some Mercedes use a linear pot hooked up to the pedal which would be easier adapted to a cable setup than a typical rotary pot
swsupermoto
Posts: 81
Joined: Fri May 30, 2014 7:36 am
ECU Model: S60 Pro
Distributor: mosley rolling road
Firmware Version: 66

Re: S40 ignition idle control Issues

Post by swsupermoto »

Why don't you set the idle by timing. Set the idle on the mechanical stop to say 1500 there use the timing to control it to a set value. Leave the main map alone
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