Holden Astra 1.8 petrol issues

Slidey

Greetings.

I bought one of these with a engine MIL on. Mate threw it on a basic diagnostics tool and it came up with O2 sensor faulty.

Got one and put it in but the light didn't go out. Got it put on better diagnostics and the same fault was showing. Went to actual values and noticed that the 2 O2 sensors were basically showing the same reading.

Cat is FUBAR I take it?

Car will never need a test unless I let the rego run out so apart from shortening the earths life cycle is there any other drawbacks? Will it be harder on fuel like this?

It also sometimes won't rev over 4k. Stops bang on this RPM so am assuming it is something elec. There is no other fault codes logged.

Anyone throw some ideas forward? Checked the throttle flap and it seems free, there doesn't seem to be a lot of crap in there either.

The rev limitation is sporadic. Sometimes it revs perfectly. When it has the limitation it seems a little missing in the lower rev band and stalls a little easier

Car is 03 btw with 170,000kms on it. One owner from new and has been parked up for over a year


Thanks in advance

crosshair1

Are both sensors showing approx 0.45v, if so this is the ecu default in the case of an o2 fault ( well thats how it works on most opels/vaux)
This voltage is measurable at the sensors so you need to disconnect them and measure their voltage to see if they are giving a signal.
What is the exact fault code?

Slidey

I didn't notice what units were displayed in the actual values. They were both reading the same, think it was something like 0.410

Fault code was p0130 I think. Will search for the piece of paper I have out scribbled on

Nissan doctor

Was this live data you were looking at or freeze frame?

In live data the pre cat lambda should be switching between 0.2v and 0.9v(approx) every 2-3 seconds and the post cat lambda should be a steady reading of less then 0.5v if the lambda's and cat are working.

If the post cat lambda is switching at all then this tells you that the cat is going/gone. If the pre cat lambda isn't switching then it or its wiring is faulty.

Slidey

Thanks for the info, will get it hooked up again and come back to ye

Slidey

After




Before I unplugged ECU








Just to rule some things out I gave the car a service and cleaned the throttle body.

When I first read the fault codes there was just the returned p0130 code. As I have already pointed out the pre cat sensor has been changed.

I took the plug off the ECU to check incase there was any corrosion but there was none. Sprayed a bit of contact cleaner in and put the plug back on. All the pins looked perfect.

When I was messing around in the menu I found something like 'faults in progress'. It made me think these were possible faults. I deleted all and re checked and there was nothing there.

I know had P0135 showing as a fault and car will not rev over 4k

In the last week I noticed that the car starts and runs perfectly in the morning from cold but if you knock it off and restart it, the engine then will no longer rev over 4k

Pre cat doesn't seem to change very little, the post cat one was changing before the ECU unplug, seems to have changed a good deal in the after shots..
Anyone got any thoughts?

crosshair1

Looks like the 0.410v is the ecu default value.
You need to test b1s1 disconnected with a meter and see if there is any signal voltage, ideally on the bench with a gas torch. If there is then its ok and you need to check the wiring from sensor to ecu.
If both are ok then the ecu may be at fault, is this mounted on the head as per its opel bretheren .

Slidey

Forgive the dumb question, how do I test it on a bench?

Petrol engines are not my area of claimed expertise!

ECU is bolted to the head, only a very short loom between the sensor and it, a quick check of wiring and it looked ok, no pinches and as to be expected in Australia, no dampness corrosion.

Any Idea of pin numbers so I can check continuity between the 2 sensors and the ECU?

crosshair1

If you place a meter across the signal & ground (normally grey & black) wires and heat the tip of the sensor with a propane torch or the likes, the voltage should increase to 0.8v ish as the tip of the sensor begins to glow.
These ecus have alarming failure rates on opels and there is a strong possibility that this is the problem here with a break in the o2 sensor circuit inside the ecu.
Wiring diagram is a z18xe opel astra not sure if this is same?

Slidey

Thanks a lot.

Have seen a mate repair the one off a diesel with the poor solder joints, is it the same deal with the petrol ones?

crosshair1

Dont think repairs a diy option, these have wires from the inside of the multiplug to the pcb that look close to the size of a hair, usually here its replace with key and immo or if you have vin of donor ecu you may be able to get key code and reset a 2nd hand unit.

Slidey

Took the new sensor back out today and had the outer cage glowing red and a multimeter hooked up to the grey and black wires and was getting nothing. Looks like it could be a faulty sensor, will get one off the net, reckon I am wasting my time going back to the auto factors where I got this one.

I also was told to check the wiring going to the cam sensor. All the plastic insulation had gone brittle and the wiring was all exposed. Got a new one off eBay.

Will update when I get a new O2 sensor fitted

szareie

Hi Slidey,

I have got the same problem, P0130, changed oxygen sensor, checked the wiring, did not rectify the issue, I was wondering if give me some advices in case of resolving the issue.

Cheers
Saeed

Slidey

I'll report back when/if I get it solved.

Think I might just get another sensor and try that first.

szareie

Thanks for your response, just an update, both O2 sensors swinging properly but I can not read bias voltage(0.45V) in signal wire by DMM in sensor 1. do you have any idea how can I check continuity between ECU connector and O2 sensor connector? Do you have ECU connector pins diagram?
PS: when I unplugged the ECU connector, I could not find any pin number.

Nissan doctor

szareie wrote: »

Thanks for your response, just an update, both O2 sensors swinging properly but I can not read bias voltage(0.45V) in signal wire by DMM in sensor 1. do you have any idea how can I check continuity between ECU connector and O2 sensor connector? Do you have ECU connector pins diagram?
PS: when I unplugged the ECU connector, I could not find any pin number.

When you say both 02 sensors 'swinging' properly? Do you mean switching the voltage up and down? If you only have a single bank engine(4 cylinder normally) then only the pre cat 02 sensor should be switching.

szareie

Quick history:
I have got Holden Astra 2001,Z18XE engine,(80000km) The engine light came on, one of my friends put the TECH2 and advised to replace both oxygen sensors(Pre & Post Cata), I replaced them with Genuine O2 sensors(NGK),But Engine light still is on. put again TECH2 ,P0130 came up,looked at the live data showing that Pre Cata sensor stuck on 0412V but Post Cata voltage changing by revving
My first doubt was may be the O2 sensors is faulty, disconnected the connectors and checked the voltage by digital multimeter with engine running,and here are the results:
At the O2 sensor connectors,both sensors swinging between 0.1 and 0.9V.
At the ECU wiring connectors:
In Pre-Cata:in heater wires, I have got the battery voltage and good ground but in signal wire I could not read bias voltage (0.45V)
In Post-Cata: in heater wires. I have got battery voltage and good ground and in signal wire, I could read bias voltage(0.45v)
So my conclusion is that there is something wrong in signal wiring between ECU and connector,(If I am wrong please correct me). looked every joint to find any damage, corrosion, no luck.
I am going to try unplugging ECU connector and check the continuity between ECU and Pre cata O2 sensor conector.can you please assist me to find out the pinout of the ECU connectors? which pin goes to O2 sensor signal wire?
any advice more than welcome.

Cheers
Saeed

szareie

crosshair1 wrote: »

If you place a meter across the signal & ground (normally grey & black) wires and heat the tip of the sensor with a propane torch or the likes, the voltage should increase to 0.8v ish as the tip of the sensor begins to glow.
These ecus have alarming failure rates on opels and there is a strong possibility that this is the problem here with a break in the o2 sensor circuit inside the ecu.
Wiring diagram is a z18xe opel astra not sure if this is same?

I will appreciate , if you send me the Post -Cata oxygen sensor wiring diagram?
I would like to know which ECU pins are concerning the signal voltages.
I checked the continuity of Pre-cata O2 sensor wiring with your attached diagram and it was perfect.

Slidey

I'm getting nowhere with mine.

Tried the propane torch, got no voltage. Checked wires between ecu plug and sensor and they were perfect.

Swooped the sensors around and the fault code stayed the same.

I was told however that these cars have poor earthing circuits and to add an extra earth wire to the cam sensor and temp sensor. I also added a new earth directly to the one that was already on the ecu body.


Ready to burn the fcuker

I did fix a leaky oil light switch, at least that's one thing off the list

Slidey

Update with this horrible bastard of a car.

Put genuine cam and crank sensors in, still not reving over 4k. Also put thermostat assy in as it was not reaching running temp.

Noticed timing belt was a little slack. Reset timing, mil went out and car was running sweet for about an hour, mil back on and limiting to 4k.

Rang a mate, he said key way on bottom pulley can wear. Took the belt off again today, key way perfect, fitted new belt and tensioners. Once started the light went out and same same, once engine got warm and was restarted it put on the emissions light and is back limiting to 4k.

I can't understand why the light goes out once the belt has been off. It never goes out otherwise. :mad:

Oh ya, 2 new O2 sensors in it too (genuine)

Nissan doctor

Slidey wrote: »

Update with this horrible bastard of a car.

Put genuine cam and crank sensors in, still not reving over 4k. Also put thermostat assy in as it was not reaching running temp.

Noticed timing belt was a little slack. Reset timing, mil went out and car was running sweet for about an hour, mil back on and limiting to 4k.

Rang a mate, he said key way on bottom pulley can wear. Took the belt off again today, key way perfect, fitted new belt and tensioners. Once started the light went out and same same, once engine got warm and was restarted it put on the emissions light and is back limiting to 4k.

I can't understand why the light goes out once the belt has been off. It never goes out otherwise. :mad:

Oh ya, 2 new O2 sensors in it too (genuine)

Have you access to an oscilloscope to properly check the signals from the cam/crank sensors etc?

Slidey

Nope. I suppose I can try and find somewhere that has one.

The thing that bugs me is why it came right after I changed the belt

Nissan doctor

Slidey wrote: »

Nope. I suppose I can try and find somewhere that has one.

The thing that bugs me is why it came right after I changed the belt

If you can check the waveforms from the cam and crank sensors and see what you are getting. The pick up for one or the other could be damaged or dirty and giving a poor contact with the sensors.

galwaytt

Nissan doctor wrote: »

Slidey wrote: »

Nope. I suppose I can try and find somewhere that has one.

The thing that bugs me is why it came right after I changed the belt

If you can check the waveforms from the cam and crank sensors and see what you are getting. The pick up for one or the other could be damaged or dirty and giving a poor contact with the sensors.

Is it possible that they are failing when hot, so some sort of resistance change due to heat ?

Slidey

That is what I was thinking but with 2 new genuine sensors fitted its unlikely.

Ecu having heat soak issues has crossed my mind a few times