Overly fast idle

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bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

Overly fast idle

Post by bazibbo »

Hi Guys

I'm stuck with a 3000k idle, and it doesn't want to get any lower :cry:


I've just fixed a few things on my loom, after discovering a mixing of sensor and standard ground, as covered in a recent post with your help. I've only just been able to test this new setup and get this all together as I had to wait for a turbo rebuild.

Things have changed hugely after getting the basic wiring right ( :oops: ) - immediately on starting, it was very lean on tickover, so lean, that I thought the wideband had died. I added fuel, and whilst I managed to get it to a more reasonable AFR, the revs shot up.

A few details:

Single throttlebody - reset stops and it's fully shut.
Throttle cable allows butterfly to close fully.
No idle valve.
I can't see that I'm getting any leaks post throttlebody.
Revving at around 2600 to 3000 around 14 AFR, on a closed throttle

I've just wired up control to a fan, as per DTAs diagrams.

Any pointers?
Antral
Posts: 194
Joined: Mon Aug 01, 2011 8:20 am

Re: Overly fast idle

Post by Antral »

Putting the wiring right will not have caused this problem you must have accidentally done something else.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Overly fast idle

Post by Rob Stevens »

If the throttle is fully shut (it shouldn't be) it must have a massive air leak.
bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

Re: Overly fast idle

Post by bazibbo »

I was thinking it was a leak around the dump valve, but that's between the throttlebody and the chargecooler - so all before the throttlebody.

I wonder if I've disrupted something

Image

Ok thanks, so as its not wiring or ecu related I'll pull out the trusty bike pump and start pressurising things.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Overly fast idle

Post by stevieturbo »

There is no question about it.

If the throttle blade is fully shut and there are no other air bypass items involved....you have an air leak.
bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

Re: Overly fast idle

Post by bazibbo »

A hole like this perhaps?

Image

It's the rear of the offside manifold, nearly impossible to see without a mirror - guess the blanking plate had decided to come loose. I think I panicked after going against my own rules and changing multiple items at once, without being able to test it.

Thanks - I'll keep it more DTA relevant next time :oops:
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Overly fast idle

Post by stevieturbo »

It's all relevant when it gets fixed.

But people do often overlook the basics and blame electronics first.
DTA Gareth
Posts: 37
Joined: Thu Feb 18, 2016 4:12 pm
ECU Model: No ECU

Re: Overly fast idle

Post by DTA Gareth »

its all good, as stevie says, getting a solution is always good
bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

Re: Overly fast idle

Post by bazibbo »

Stevie's right though - my immediate though is always electronics.

It's the bit that frightens me :roll:
Antral
Posts: 194
Joined: Mon Aug 01, 2011 8:20 am

Re: Overly fast idle

Post by Antral »

bazibbo wrote:Stevie's right though - my immediate though is always electronics.

It's the bit that frightens me :roll:
You are not on your own most people blame the electronics before looking at what they have also done.
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