2002 vw polo 1.2 AWY

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craigM
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Joined: Sun Mar 24, 2013 3:14 pm

2002 vw polo 1.2 AWY

Post by craigM » Fri Feb 22, 2019 10:07 pm

Hi, having an issue with a rich running issue with my father inlaws polo

waters pretty muddy unfortunatly

Bit of back ground info-
Back in august he was having running issues and compression test was carried out and it had the usual burnt valves.
I advised him to get a new cylinder head and left it at that, he likes to do his own work and the last i heard he had ordered on.
A few months later he was complaining it wasnt running right- at this point i discover the head hhe ordered got lost and damaged in the post and he decided instead of waiting for another to send it back for a refund.
He then reseated the original valves and refitted the head with a new chain kit.
By the time i got to it all ignition coils, plugs, map sensor, temp sensor, injectors(second hand) and both lambdas have been replaced.
Not sure why he didnt speak to me before all this :roll:
So its setting 16514 - Oxygen (Lambda) Sensor B1 S1
P0130 - 35-10 - Malfunction in Circuit - Intermittent
This triggers at idle once the fuel trims go over -10 and the lambda stops switching and sticks at 0.45v before going to 0.79v and staying there till you switch off and clear the codes.
No volt drop on signal wire.
If you cause an air leak the lambda reacts instantly
I was going down the route of still having valve issues but all compressions over 200psi
Vacuum guage reading 20inhg
First look sensor has equal peaks(first time using it though)
Did cylinder leakage test and valves are sealed but have a slight leak past rings- flow guage is faulty so not sure how bad(new one coming tomorrow)
Fuel pressure within spec and pressure regulator is working
Checked exhaust back pressure and no pressure detected on guage

Cant seem to see a good cam crank on the pico library for this engine to compare

So other than checking the timing and another leak test on the rings what else am i missing?
Bit rusty with the pico not used it for over 2 years as im now roadside for a motoring club so dont tend to get to indepth either now so any assistance is appreciated

landroverman1958
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Joined: Thu Dec 04, 2014 7:53 pm

Re: 2002 vw polo 1.2 AWY

Post by landroverman1958 » Sat Feb 23, 2019 10:18 am

Good morning there is a post on here as far as i remember about wrong fuel filter(s) been fitted to some cars,its got a built in fuel pressure reguator fitted on some cars, check the filter is the correct one for this vehicle.
This will mess up the fuelling stratergy,sorry cant spell today.

KimAndersen
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Location: Denmark

Re: 2002 vw polo 1.2 AWY

Post by KimAndersen » Sat Feb 23, 2019 11:27 am

The dtc you are referring to are related to heater circuit of the oxygen sensor - so check the resistance of this circuit which should have a resistance between 1 to 5 ohms.

You could also check how much amps this circuit are consumeing with a current clamp around the feed wire to sensor.

Regards
Kim

Technician
TwoWaves
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Re: 2002 vw polo 1.2 AWY

Post by Technician » Sat Feb 23, 2019 8:57 pm

craigM wrote:
Fri Feb 22, 2019 10:07 pm
Hi, having an issue with a rich running issue with my father inlaws polo

waters pretty muddy unfortunatly

So its setting 16514 - Oxygen (Lambda) Sensor B1 S1
P0130 - 35-10 - Malfunction in Circuit - Intermittent

This triggers at idle once the fuel trims go over -10 and the lambda stops switching and sticks at 0.45v before going to 0.79v and staying there till you switch off and clear the codes.

I was going down the route of still having valve issues but all compressions over 200psi
Vacuum guage reading 20inhg

First look sensor has equal peaks(first time using it though)

Did cylinder leakage test and valves are sealed but have a slight leak past rings- flow guage is faulty so not sure how bad(new one coming tomorrow)

Checked exhaust back pressure and no pressure detected on guage

Cant seem to see a good cam crank on the pico library for this engine to compare

So other than checking the timing and another leak test on the rings what else am i missing?
Hello, based on the above readings I'd be leaning towards no mechanical problems. If the valve timing were out of sink then the engine vacuum would be low and steady, 20 InHg is respectable. Some leakage past piston rings will always be present, an engine must to some extent be allowed to breath, even in closed circuit crankcase systems.

craigM
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Posts: 4
Joined: Sun Mar 24, 2013 3:14 pm

Re: 2002 vw polo 1.2 AWY

Post by craigM » Sat Feb 23, 2019 9:22 pm

Hi, this model isnt fitted with a regulator in the filter, it was one of my first thoughts and had my parts supplier check on the vw system to confirm its correct.
Feeling a little silly for not looking further into the fault code. sensor heater circuit is 2.4ohms
will try get the scope on the heater circuit in the morning.
cylinder leakage is just over 20% on all cylinders so not to bad.
Thanks for your help guys.

craigM
Newbie
Posts: 4
Joined: Sun Mar 24, 2013 3:14 pm

Re: 2002 vw polo 1.2 AWY

Post by craigM » Sat Feb 23, 2019 9:35 pm

yes its the conclusion i have came to.
Seems he replaced an aftermarket lambda with another from euros which may explain a lot.

landroverman1958
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Joined: Thu Dec 04, 2014 7:53 pm

Re: 2002 vw polo 1.2 AWY

Post by landroverman1958 » Sat Mar 02, 2019 11:01 am

It has been known for the o rings to leak letting unmetered air into the inlet manifold,around the injectors.

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