Lambda sensor bad?

[yamstar]

Mein C3G 1994 hatte 2010 ähnliche Probleme. Erst hiess es in der Werkstatt der Kat kaputt, dann völlig komische Werte in XR25pc die ich selber augelesen habe. Da ich der Software nicht getraut hatte und ich kurzerhand mit ner Leitung zu nem anderem Auspuff doch noch die AU geschafft hatte, bin ich das Auto bis 2012 gefahren und habe mir dann nen 2001er geholt fürn 700€. Beste Entscheidung...

Hatte mir sogar damals nen neues motorsteuergerät bei Ebay geholt. Hat aber nix gebracht. Der Verbrauch lag bei um die 12liter.

[ronenfe]

Failed again , lambda high, co passed after redoing the test after warming up the engine on 3500 rpm.

[cooldriver]

Exhaust leakage. The donut ring needs no paste. And close the pipe downwards the engine in the air box.
Its for eliminating powerless warm air. Map sensor should be tested.

[ronenfe]

I had to put paste outside the donut ring because there was a leak. I retested and no more leaks.
Tested fuel pressure. 1 bar ok. Tested fuel pressure regulator by pinching return hose. 2.5 bar ok. Tested fuel flow. 1.5 liter in 50 seconds ok. I removed the monopoint system and going to test . Already found the bottom gasket doesn't look good.

[ronenfe]

They finally let me pass after few tries. On high rpm I can get it to the 1.03 limit. I have no idea what else I can do to make the lambda lower. Nex year I will try to put paper towel in the exhaust if they let me.

[ronenfe]

I was able to use all clip functions today without any disconnections even with engine running and I recorded some values. I think all good. But after my tests I think I started to have a misfire.

[cooldriver]

Wait for warm engine. Lambda is almost inactive, but also reacting too late .
Record rpm, throttle, speed, absolute pressure and lambda, idle and when 2500 rpm.

[ronenfe]

Look what I found. It probably happened when I tested the engine in high rpm.

[cooldriver]

Really bad, but luckily admission valve.
I think its an old version without counter nuts.
So why could this happen? Look for the nut.
This is why valve clearance has to be checked so often in C3G.

[ronenfe]

Took me a while to find the nut, I was worrying it can get inside the engine, but luckily there are no big holes there, and it didn't break anything above, it was in the hole of the same push rod, I realized it after I saw the push rod was not moving freely. I had to take out the whole valve shaft and the push rod and it fell inside the hole, I managed to dig it at the end with a magnetic screwdriver but it wasn't easy.
Maybe it happened because the nut wasn't tighten strong enough.

[Broadcasttechniker]

Naja, jetzt weißt du wenigstens dass man gut kontern muss.

[ronenfe]

What do you think?

[cooldriver]

O2 Sensor looks really bad, except when in higher rpm.
Could be a leakage in the manifold or pistons.
Good Sensors have 0.2 to 0.9 volts.
U should drive a while at higher speeds to get rid of petrol in the exhaust.
The rest is out of sight for more help.

[ronenfe]

Turned out the new Delphy o2 sensor was bad or got bad within a year. I put the old one back and it looks like it functions better, but I'm not sure if idle is ok now. Also I will try to replace the brushes of the alternator. Seems like voltage is too low.

[ronenfe]

With the old lambda sensor and after using Rheinol cleaner: https://www.swdrheinol.com/en/product-de...m-cleaner/

I passed the emission test.

Thanks.