[Mk2] [Turbo] Bad idle

Anything and everything to do with mechanical issues with your Mk2

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Michaeljwestern
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Joined: Mon Sep 02, 2013 8:14 pm
Location: Northamptonshire

[Mk2] [Turbo] Bad idle

Post by Michaeljwestern »

Hi, I've a mk2 turbo sw20 , I've done a few mods, decat, blitz dump valve, recently serviced, new plugs leads and cap with arm,
When I stop at a junction, the revs drop to about 400rpm then pick back up to 800rpm, my problem is when the engine is hot, it drops to about 200 rpm and dies, I've checked and cleaned idle control solenoid , plug gaps, vacuum hoses,
Anyone had same problem ? Or ideas
jon
Posts: 341
Joined: Tue Dec 14, 2004 10:23 am
Location: Cambridge

Re: [Mk2] [Turbo] Bad idle

Post by jon »

Make sure the throttle position sensor (TPS) is set up correctly.
Turbo Dragon
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Joined: Sat Nov 19, 2005 1:49 pm
Location: Wherever TV needs sound.....

Re: [Mk2] [Turbo] Bad idle

Post by Turbo Dragon »

Had a problem with mine like that it was the air flow meter sticking and not registering correctly.
joemacmr2
Posts: 189
Joined: Mon Jan 28, 2013 6:44 pm

Idle

Post by joemacmr2 »

Did u mark rotor arm when changing cap and arm. U could have retarded timing which would do this.
mrdb
Posts: 169
Joined: Mon Apr 30, 2007 11:00 am

Re: [Mk2] [Turbo] Bad idle

Post by mrdb »

Sounds like a vac leak when hot to me.

Check around injector / tvis etc also leaking rocker cover gasket causes an air leak.

But also as said the AFM could be on its way out / sticking.

You cant put the rotor arm on wrong or the cap so timing cant be out if was set originally right. Timing can only be altered via rotating dizzy.
Tedtiler
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Joined: Tue Oct 30, 2012 7:42 pm
Location: Belfast

Re: [Mk2] [Turbo] Bad idle

Post by Tedtiler »

Did it start specifically after one of your mods like dump valve? It's probably vacuum leak on intake side somewhere. Don't touch the tps unless you really have to.
bobhatton
Posts: 3351
Joined: Fri Aug 25, 2006 9:34 pm
Location: Bodmin Cornwall

Re: [Mk2] [Turbo] Bad idle

Post by bobhatton »

Michaeljwestern wrote: I've checked and cleaned idle control solenoid


There is no solenoid for idle control. The control is under the TB
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
Super_red
Posts: 542
Joined: Mon May 09, 2011 7:10 pm
Location: Guildford

Re: Idle

Post by Super_red »

joemacmr2 wrote:Did u mark rotor arm when changing cap and arm. U could have retarded timing which would do this.


You will only change the timing if you rotate the distributor body. The spark is ECU controlled so the position of the arm on the rotor will make no difference, it will only move about 3 degrees each way anyhow. The ECU pickup is in the distributor body so if you rotate this then the timing will change.
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