Daewoo Lanos (1997 - 2002 ) - 2000 1.6 - hesitation on light throttle (cold)

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Mon 19 Nov 2007 10:19
2000 1.6 - hesitation on light throttle (cold) - GregBlack
Hi Guys,

The Daewoo (1.6 ecotec, 2000 V, 103k) is very hesitant when the engine is cold. It starts first time when hot or cold. On first starting, the revs go up to about 1500, then drop back down to idle at 800-1000. If you dab the throttle, the revs drop a bit before increasing. Coasting in gear and then applying light throttle causes the car to jerk quite severely before the revs pick up and off you go. This is a real pain in morning traffic! After about 5 minutes running, it is near perfect. So far it has had a service including oil, oil filter, air filter and new Bosch spark plugs. The old spark plugs were dry and a nice brown colour. Servicing has had no effect on the cold running problem.

The problem is the same whether it is a warm day, a cold day or a wet day.

Any ideas on the likely cause?

Thanks for any suggeestions,
GB

Edited by Dynamic Dave on 19/11/2007 at 10:24

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Mon 19 Nov 2007 10:43
2000 1.6 - hesitation on light throttle (cold) - piston power
you say the plugs were brown? that says to me water is in the cylinder causing a misfire, have you checked for any air leaks etc
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Mon 19 Nov 2007 10:54
2000 1.6 - hesitation on light throttle (cold) - Screwloose
Greg

The symptoms would suggest a coolant tenp sensor issue; but an air leak or things like a tired MAP sensor could also be involved.

It would seem that as soon as the oxygen sensor is warm enough to go into closed loop, the ECU compensates for the lean-ness.

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Mon 19 Nov 2007 11:12
2000 1.6 - hesitation on light throttle (cold) - GregBlack
Thanks screwloose, do you know where the coolant temp sensor is located? I understand that the MAP sensor is an oxygen sensor. Do you know where this is - on the inlet manifold perhaps?

Many thanks for your help.
GB
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Mon 19 Nov 2007 11:27
2000 1.6 - hesitation on light throttle (cold) - Screwloose
GB

I haven't seen one of these for ages; but I've a feeling that it's in the inlet manifold.

The MAP sensor is a totally different thing to the oxygen sensor - which is in the exhaust.

Getting someone with a Daewoo scanner [not easy] to check the live readings would be the best way to proceed; swapping parts is not a good idea, Daewoo parts are twice the price of BMW ones.
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Thu 3 Jan 2008 01:11
2000 1.6 - hesitation on light throttle (cold) - Pud
Hi Gary,

Would be great if you could post again here if you manage to find a cure for this problem. I have almost exactly the same problem on my wife's Lanos (same engine, same age) except that it doesn't improve when warm. It makes the car pretty unpleasant for me to drive and just about impossible for my wife.

Cheers,

David
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Thu 3 Jan 2008 09:29
2000 1.6 - hesitation on light throttle (cold) - jc2
MAP sensor measures Manifold Absolute Pressure and will be connected either directly or by a pipe to the inlet manifold;Oxygen sensor is in exhaust and is also called a Lambda sensor or (H)EGO sensor.(Heated)Exhaust gas oxygen sensor and is used to maintain stoichometric air/fuel ratio.In theory-perfect combustion!
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Fri 5 Sep 2008 16:12
2000 1.6 - hesitation on light throttle (cold) - olidude
hi Ive been reading the posts because my lanos was juddering when on light throttle, had an irregular idle and started using more fuel, I changed the plugs and the leads and still the same problem, today I replaced the ecu temperature sensor (located underneath the inlet manifold - you can get to it from underneath the car without removing anything else) it cost me £16 I then disconnected the battery for 20mins so the ecu would reset, connected the sensor then the battery, the car is running great again now.
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Fri 26 Sep 2008 16:09
2000 1.6 - hesitation on light throttle (cold) - Mehdi72
Could someone tell me the location of the map sensor? My wife's Y Reg Lanos 1.6 has developed the same fault listed in this thread. I've got a replacement map sensor unit but my friend took a look under the bonnet and we couldn't locate it.
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Mon 25 Nov 2013 16:24
2000 1.6 - hesitation on light throttle (cold) - panther

I know it's an old thread but thought I'd post in case it helps someone else searching for a similar problem with the Lanos. I had the same problem with hesitation & flat spot on acceleration when cold. Would run great after about half a mile but from cold it was very annoying when applying throttle it would buck & jerk.

I've just replaced my throttle sensor (TPS) and that seems to have cured it. I was a bit sceptical that it was the TPS as I would have thought it would do it all the time and not just from cold? However the last few cold starts since replacing the TPS and it's now a smooth engine pick up when applying throttle.

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Mon 25 Nov 2013 17:49
2000 1.6 - hesitation on light throttle (cold) - Cyd

Try cleaning the throttle body and butterfly. A little of this stuff and an old toothbrush. Don't swamp it. Dry out excess with a cloth.

www.toolstation.com/shop/Carburettor+Cleaner/p30713

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