High emissions at idle, code 57

[VectraGoVroom]

Veccy flunked her inspection, intermittent cutting out at idle and revs. Nothing major, just skipping a beat now and then, but it was enough to go over the line. The guy even told me the numbers look fine when it's running evenly, and suggested I take a look at the ignition system first. I replaced the spark plugs, dizzy cap and rotor arm, now it's better on the revs but still wavers around a bit on idle. Tried cleaning the IACV, no dice. Throwing code 57. I've got the battery disconnected right now to see if it comes back, any other diagnosis tricks I can try? The valve is a bit expensive to buy a new one right off the bat.

Engine's a C20NE.

[Mk3alan]

HT leads ok?

Alan

[VectraGoVroom]

I inspected them and they seem to be fine, any test I can do for those? The number 1 spark plug seemed a bit whiter than the rest. Resistance across the ICV is 8 ohms and the plug is getting voltage just fine. I set up a camera to peer inside the valve while I cycled the ignition, no movement. It's had a wavering idle as long as I've had it, never failed emissions before though.

[Robsey]

Code 57 is idle control valve high voltage.

Never could suss out the meaning of voltage high or voltage low.

It may be that your valve is gummed up and sticking... the internal rotating valve bit should move quite easily.

I would still check your wires and connector pins to ensure that the wires are not damaged and the pins are clean and secure.

I chased a low revving C20NE issue for ages after it started to cut out on a hot start.
The car ran fine for years at a low rev, but the only true cure of a hot start cut out was replacing the idle control valve.
Not at all cheap.

As you have a C20NE, do you have the correct octane plug.
I was unaware until James told me last year, that the correct octane plug is yellow.
The yellow plug raises the idling rpm by approx 100 revs.

Old black coding plug.



And new yellow coding plug.



In my case, I could not see an obvious difference, but mine has lots of post restoration issues that I am still struggling with 14 months down the line.

Finally - I still have EnvoyCDXs voice nagging my conscience saying " check all the ground wires". There are about 4 for a typical manual C20NE injector loom.

[VectraGoVroom]

Already sprayed the plugs with contact cleaner and checked the connector for voltage. Octane plug is yellow. I've cleaned the thing twice while I've had the car, but I suppose third time's the charm. I'll try working the valve with a screwdriver, see if it moves at all, maybe give it a bath in some WD or brake cleaner or whatever. There are some new valves on ebay for 25-ish quid, are those worth a damn at all?

[Robsey]

I suspect that they would not be very good items, but I could be wrong.
They sound like used parts at that price, but there is no guarantee that new or used partd will solve your issue.

A regular clean does help a lot.

I flushed mine with carburettor cleaner or brake cleaner, and then filled with a thin 3-in-1 oil to relubricate the internals.

Drain out and refit - worked for me for many months... I just got fed up of cleaning it every few months.

Do not forget to clean your breather hoses as these get filled with oil and so contaminate the throttle body and the idle control hoses.

I have tried to use Bosch or GM parts only, but prices are silly.

[iangsi]

The Lamda sensor in the exhaust affects the idle, changed mine on my 1.8 NZ improved the emissions & lumpy idle no end.

[Robsey]

The C18NZ has a slightly lumpy idle anyway.
Obviously the lambda affects the fuel / air mixture and is the weakest link in the Multec injection set up.

C20NE is a totally different breed of animal.
With it's own little quirks.
The air flow meter and the idle control valve are the "weak spots" of this otherwise reliable set-up.
(You would not believe this, if you saw how many threads there are currently running with affected C20NE units).

[VectraGoVroom]

Welp, the valve moves smooth as silk, yet no reaction at all when I connect some 12V test leads to the pins. Guess it's done, time to order a new one. Could this be the cause of a slight flame in the exhaust when coming off hard throttle, as well?

[VectraGoVroom]

Ookay, what the hell. Moments from pulling the trigger on a new valve, I decided to test it with a loose battery one more time. Snapped over like nobody's business. Measure the voltage at the connector again, perfect voltage. Plug it in, turn on the ignition, nothing. What am I missing?

E: Kind of at wit's end. With the valve connected and ignition on, I decided to move the valve a bit with a screwdriver and see what happens. Felt a little electric buzz resisting me when I moved it, so it's definitely doing something. Took a video, what does this sound like to you all? It's high HC and CO, by the way.

Link


I sprayed a bunch of carb cleaner around looking for vacuum leaks, didn't seem to find anything. Here's what the plugs looked like, maybe something funky going on with cylinder 1? Injector trouble, maybe?

[Robsey]

The first plug looks more coated than two and four, but that will just be all the fuel additives.

It is the third plug that catches my eye.
There is no combustion related coating on that plug - as if nothing is happening.
Is number three getting a good spark?

So you have applied voltage to the ICV and it moves rapidly.
Is the ICV wired the correct way round?
(Polarity).

Maybe you need to try it with the engine running but hoses disconnected from the ICV.

Try using your hand between the two hoses as a pretend valve - varying the amount of air allowed to past you hand / fingers.

You may find restricting the air flow between the pipes may cause the valve to open on the ICV.

Just a thought...

[VectraGoVroom]

Hm. Not sure about the plug residue, but I'll worry about that beyond checking the spark once I've got the valve issue sussed out. Its current behavior doesn't make sense to me -- A two-pin valve is electronically actuated one way and returned by the spring, so why would the current applied by the car move the valve in the same direction as the spring? I'll check the polarity I used while testing and compare it to that of the plug.

Of course I get all my ideas when I'm home dead tired from work, and the car's a bit of a drive away. If it turns out to be the polarity, I'm just going to modify the plug to fit upside down. I don't even care about the idle, I just need a fresh inspection stamp...

[Robsey]

Just checked your 57 code...
It suggests that the wires are shorted to earth.
Look further up the loom for a wire with damaged insulation or exposed internal wire strands.

This would cause the ecu to shut that wire down to prevent further damage to the ecu or loom.

[VectraGoVroom]

Okay, I took another look. All plugs are getting spark just fine, and that plug does have the same residue on it as the rest. Maybe it just got a little oil on the tip, I gave it a scrape and found the same white stuff.
I found a bit of fraying on both wires near the valve's connector, too close to the plug to do anything but throw some electrical tape on there. The polarity is the same as I used while testing. Maybe it's only getting voltage at the plug with the valve disconnected?

There we go! I did another test while typing this, turns out we've been barking up the wrong tree. I stuck screwdriver handles in both the hoses, rigged my phone camera to peer inside the valve and started the car with a little throttle, and it turns out the valve opens up just fine. Maybe a trick worth passing around?

Also, any idea what the little black box with two wires and a hose going to the intake, mounted in between the fuel rail and head is? The hose had a kink on it, so I cut a piece off and rerouted it.

I'm frankly getting a bit fed up. I just put a full bottle of injector cleaner in a quarter-tank of gas. As soon as I get off work, I'm clearing the ECU parameters, going for a drive, giving her the beans, getting the cat nice and hot and taking her to a garage to try another emissions reading. I tow that shop a lot of work, maybe they'll even read it for free. After that, it's new front brake pads and rotors and hopefully a fresh stamp.

[Robsey]

If it is the one with the red insulator on the connector, then I think it is the carbon canistor "fuel vapour" control valve.
Some form of vent valve.

[VectraGoVroom]

No dice, still high HC. Reckon I'll take a look at the coil next, run the tests outlined in the Haynes and replace the HT leads if that turns out fine.

[Robsey]

High Hydro-Carbons eh.?

Do you have any smoke in the exhaust?
High HC can be valve issues, so may be worth doing a compression test.
(Sticking valves, worn guides etc).

[VectraGoVroom]

I doubt that, it's clearly misfiring. You saw the video, and it's even clearer in person. Easy to hear around 27 seconds when I'm holding some revs.

[Robsey]

Sadly, I was unable to see the video.
Apparently it is not supported on my phone.

As mentioned, my comment was that it "may" be valve issues.
So I am pleased that you are confident that it is not.
A misfire indicates a few potential sources.
1 - plugs,
2 - leads,
3 - injector or it's wiring
4 - rotor arm or distributor cap.
5 - ECU wiring.
The C20NE uses batch firing injection, so all other possible causes would affect all four cylinders - not just one.

I am sure the obvious plugs, leads, rotor arm and distributor cap have been sorted, so this leaves -
1 - sticking or clogged injector.
2 - faulty wiring or connector to an injector.
3 - faulty wiring or connector to the ECU.

As you have found damage in other parts of the loom, my conclusion is a very tired loom.

Favourite is the injector connector wiring.
It sounds like the previous owner was less than careful when working in the engine bay.

[VectraGoVroom]

Here's a direct link, maybe that'll work. https://www.youtube.com/watch?v=ShUXUKIALdk

Hmm... Reckon I should change the HT leads as a part of maintenance either way? I think I'll borrow a compression tester from my brother and run a test just to be safe. I'm thinking I'll:

- Compression test
- Replace HT leads
- Clean coil connections
- Check coil resistances
- Check and clean injector connectors
- Pull injectors and run this test to clean them and inspect spray pattern: https://www.youtube.com/watch?v=8rk0tKtiVic

Sound good? I'd appreciate an abridged guide to pulling the injectors, the Haynes is confusing me a bit. I'll pull the fuel pump fuse, run the engine until it cuts out, remove the clips from the connectors and pull the electrical rail, then what?

[VectraGoVroom]

Replaced HT leads, no change. Pulled coil, checked resistances, .9 and 7k Ohms. Could the air flow meter cause any of this? I saw a video on opening one up to clean the wipes or move the arm to a fresh spot of conductive stuff that hasn't been rubbed for 400,000 kilometers. If you think that's worth a shot, I think I'd try that first before starting to mess with the injectors. Here's the video: https://www.youtube.com/watch?v=-11J8XawQtc It's from a Porsche, but it looks like about the same unit? The comments recommend loosening the four screws the board are on and moving it very slightly forward or back instead of bending the arm. What do you think?

Disregard that about the Haynes guide on injector removal, by the way. Turns out the book of lies is a lot easier to read when you're not slightly drunk on scotch.

[Robsey]

I am being cautious here...
I think more than one fault exists.
One partially confusing the diagnostics of the other.

Air flow meter will affect the mixture settings, so you should expect high CO levels.

As said high HC suggests incomplete fuel consumption AND you say you have a mis-fire.

Your plugs looked fine. Nice beige coloured deposits on three of the plugs.

The other plug looks like it is not firing.
If the plug is fine and the HT lead is fine, then what condition is your distributor cap.?

From memory it was plug 3 that looked different.
Only two possible causes.

1 - Injector 3 electrical connector (common weak spot on many Opel / Vauxhall models.
2 - worn electrode inside distributor cap.

And separate from the mixture issue is the ICV fault, which you have already said has some frayed wiring.

I feel like a cracked record - I keep coming back to wiring and connectors.

Repair the ICV wiring
Inspect and repair No3 injector wiring.

[cavalier1990]

Good overview of emission problems here, worth a read:


http://www.petercoopercarrepairs.co.uk/new_page_2.htm

[VectraGoVroom]

Well. I don't know if the shop guys looked at the wrong emissions chart or did some shady stuff, but I took a second look at the emissions slip they gave me and everything actually was in order. I said sod it, fixed the brakes and got her inspected again. Thanks for all the help, but I'll let her be lumpy as long as she gets to stay on the road. She runs and pulls just fine, it just gives her character.

[Robsey]

Good to hear that the emissions are okay.

As for the slight mis-fire. That sounds like what my garage said about my car, even though I didn't really notice it due to being used to the cars quirks.