156 wonky idle - THE FIX !!!!

Hi all

Just wanted to let you know my experience.

So i have an Alfa 156 2.0 selespeed auto, year 2000.

I was getting the exact same symptoms when I was breaking, coming to a junction, etc the car would always want to cut out, then recover.

I had this problem for a couple of years and just got used to it, as I didn't have that much time ot take it to Alfa.

The last few months it got worse and worse, nearly crashed the car turning into a tight side street a few times as it actually started to stall and the power steeering cutting out.

I tried the first reccomended reset.

1. I disconnected the battery, left it for a few hours. connected it back then started the car and left it on idle for 30 minutes before setting off.

This fixed the problem straight away. However after turning it off and setting it off again it when back to the same old problem.

2. Then after nearly crashing it again, I have gone for option 2, snipping the wire behind the speedometer as described on this thread. I was desperate. at first when I started reading this thread, I thought it was drastic, but not now.

Straigth away the car is fixed, like a totally different car.
Just one side affect, the accelerator reaction is a bit sharp when you take the foot off it at lower speeds, ie when you want to slow down. But its nothing compared to nearly crashing it.

I know this has masked the problem, but my car is on 82k, and spending all that money with Alfa does not seem worth it.

As described before, it only kicks in after you go over 10mph, but its ok. I am more than happy. Sure it has masked the problem, but it does not bother me.

BTW, its the green and black wire for me and I did not disconnect the connectors form the unit. took the keys out though.

Thanks for this thread, and thanks for the suggestion and peoples posts. I am very happy.
Sorry one more.......

I got another bella and it's got the dreaded bouncy revs, I'm pretty sure it's the stepper motor ie idle actuator, so it's either pay the £200 or whatever for new actuator fitted or cut wire as before

I heard you need idle actuator fitted with special equipment! So no diy job then

If you have AlfaDiag you can fit it no problem, easy to fit then reset idle actuator with alfadiag. Sometimes takes more than one attempt to get the idle set correct.

Originally Posted by Maverick

If you have AlfaDiag you can fit it no problem, easy to fit then reset idle actuator with alfadiag. Sometimes takes more than one attempt to get the idle set correct.

Ah cool, I just got a dual core laptop and I have AlfaDiag demo, so I'll have to invest in the lead now

I hope the demo version is ok though!

Originally Posted by sa155ae

Ah cool, I just got a dual core laptop and I have AlfaDiag demo, so I'll have to invest in the lead now

I hope the demo version is ok though!

I think the demo version only allow you to connect and check a few sensors and ECU info, but you won't be able to reset the actuator with the demo version. But it's a good investment, will pay off very quick.

Where can you get software and cable? I checked Gazza's site for info on cable and it's sold out

AlfaDiag Alfa Romeo Diagnostic Software

USB ISO OBD-II / VAGCOM / AlfaDiag KKL Interface keywords [USBVAGCOM] - £29.99 : ECUFix.com, Affordable Technology

I`m sure you can get a cheaper cable from ebay.

You can tell if the idle actuator is causing the problem by leaving it plugged in but taking it off the side of the throttle body. The throttle body remains sealed so you do not affect the fuelling through the throttle. You have to take the throttle body off to do this (4 star screws) and then the idle actuator comes off (3 star screws). You don't have to remove the throttle cable to do this.

The above made no difference to mine proving that my fault was not with the idle actuator.

My usb cable has arrived, I just have to download software now to see where the fault lies

Originally Posted by Gibraltar

I still have a similar problem on my Vauxhall Omega Estate. Very intermittent. The danger is that the engine can cut out on the approach to junctions or when slowing down generally so I lose the power steering which is a nightmare. My garage has tried everything with no permanent "cure". I will pass this info on, but just wanted everyone to know it's not just Alfas that have such problems.

Hi Gibralter,
My wifes Focus does this too. Very disconcerting!

I took the idle actuator off my spare car and when I took the idle acuator apart it's only a little motor inside. Flippin heck £100 odd quid for a little motor what a rip off!

Just wanted to say - wire cutting worked for me too. What a relaxing drive i have now. Well done. That has been an issue with this car for a year. Now I have to explain to my mechanic why I don't need that 400 €uro worth of replacement parts, and ask if he wouldn't mind sending them back.

wire cutting isnt a fix, it simply hides the problem. replace the idle speed actuator (£10 scrapyard part). in some cases adding washers between the actuator and throttlebody sorts it (for reasons unknown)

Originally Posted by sa155ae

I took the idle actuator off my spare car and when I took the idle acuator apart it's only a little motor inside.

its a solenoid, so bascially a small electromagnet and a plunger the magnet can move back and forth. for some reason fixing the damn thing is difficult considering how simply it is made.

Hi all
am new to Alfa so needs so help with my wonky idle.I have a year 2001,1.6TS 156.
My problem is that when you start the car it will sit at 1200 RPM.
When the car is warm i find that when i slow down and stop my car will idle at about 1500 to 2000 RPM.
If you try and blip the throttle then it will come back down to 1200 RPM,sometimes.Other times it just sits at 2000 RPM.
Apart from this problem the car runs fine.

Sorry to be a pain guys but as i say am new to Alfa.

cheers

jimmy boy

1200rpm!! thats far too high, it should be 850rpm.

check the intake and all hoses connected to it for leaks. even a cracked hose could be causing a vacuum leak which causes your high idle.

It could also be set high on the throttle cable (the 1.6's are cable aren't they?)

true, an incorrecty adjsuted cable could be holding the butterfly valve open. check if the cable seems tight at idle on the throttlebody, and try slackening it off a coupe of notches on the adjuster.

Does sound like your idle may just be too high rather than the infuriating fluctuations/bouncing that can occur.

Theres a grub screw idle 'adjuster/stop' on the arm of the throttle on my '98 2.0 TS. Look where the throttle cable actually turns the throttle mechanism. There are some differences between the throttle set ups etc. on the 156 so yours could be completely different. If yours has one of these and it's been wound 'in' too far - this could be giving yours a high idle. Try turning it 'out' half a turn and see if the idle drops at all.

Classic air leak locations are in the deepest parts of the corrugated rubber inake hoses where the rubber perishes and cracks

You could also try an ECU reset -

Disconnect battery positive terminal for at least 45 mins.
Ignition on 90 seconds - don't start the car.
Ignition off 90 seconds.
Start car - no throttle - and leave to idle for 10 minutes.
Test drive.

On my cable throttle there's a C clip that is used to adjust the cable position, if it's too thight it will raise the idle. If that's the case, just move the clip so the cable has some room allowing the B/V to close.

A high idle could also be caused by a faulty idle motor and a couple of other things. Do you have the warning light on?