Workshop Couldn't Figure It Out... Engine Beeing Jerky And Using Alot Of Fuel

[Norlig 1]

is lambda sensor disconnected?

 

Yes

[alfizta 6]

So TRA, DTV and FRA not changing is normal. These numbers only change when you have the lambda sensor connected, until you get a closed loop signal, i.e, proper rate air/fuel.

[Norlig 1]

Would the RPM act like this when the lambda is disconnected, when idling?

[Smaky 73]

Yes.

[alfizta 6]

Smaky, have you looked to idle between 248 and 265 seconds (on picture)?

 

Norlig, Is your idle stable at 850 rpm? If not, it's better to plug the lambda back again...

Can you post a pic your intake system like you did on AO. Maybe Smaky could give his opinion on it

Also, I agree with you. I find it strange that "desired air quantity" is much lower than "air quantity". Also, don't understand those peaks of injection times and air quantity when rpm is almost constant (on video)... I'll try to check on mine when I have a chance.

Edited October 25, 2013 by alfizta

[Norlig 1]

I had it like this before, got told I should put it back to original as this introduced too high air temperatures to the engine:

 

 

Bought a new Air filter and took it back to stock air after that, currently its sitting like this:

 

 

RPM does Fluctuate like the picture in my post above for 85% of the time when I press in the clutch, but its more apparent when the car is moving forward for some reason. (as you can see when I parked (747 seconds)

 

if I press the clutch when standing still, it does not always fluctuate like that

 

at 13.25 minutes in the video, you see me play with the throttle while checking the throttle position.

it is 3.3 deg. when idling, but if I use the pedal and then when I let it go, it drops to 2.8 deg. for a second, then goes back to 3.3 deg. could this be the initiation of that up,down,up,down with my RPM? that the valve closes too much, causing the RPM to drop, causing the ECU to open it automatically, causing the RPM To rise and then it closes, etc, etc?

Edited October 25, 2013 by Norlig

[Smaky 73]

Replace the MAF, after looking at those pics and referencing the graph I would be concerned that the MAF element is contaminated and now probably cooked, you don't get a code unless it has completely failed but I would strongly suggest a NEW BOSCH MAF be fitted.

[Norlig 1]

New MAF and lambda, or only MAF?

[alfizta 6]

just MAF. since you still have idle issues with lambda disconnected, probably lambda is still good (that's what I think Smaly is thinking...)

 

still I think we should try to find if you got the correct lambda. can give us the lambda make and part number and your alfa chassis number?

 

but before try cleaning your MAF. you could get lucky excellent guide here:

http://www.alfa156.net/fr_index.html?/tech/MAFguide/

 

another thing, did you do the idle reset with 30 seconds time period or 90 seconds. I think MES directions are wrong on this. I always use the 90 seconds...

[Smaky 73]

Only MAF, though I can see your #3 coil pack isn't plugged in properly in that picture.

[Smaky 73]

And who replaced that crank sensor??? The wiring is routed wrong and did they make sure the old O-ring was removed as that can cause a rough idle if the engine will run.

[alfizta 6]

what about the cable wraped in front left on the engine, 1st picture. that should go down to the ac compressor, through that small black plastic clip at the left of the engine, right/wrong?

[Norlig 1]

I replaced the RPM/crank sensor. I did read up on it and did remove the old O-ring, but does it matter where the cable goes? (interference?) it was very little room behind there and don't think I will be able to get it into the right clip by ease.

 

I will also give the coils a push to check if they are seated correctly.

 

I have a spare bosch MAF that was in the car before the one I have now. I will try to give that one a clean and see if it helps. I did clean the one currently in the car and I cant remember if it helped or not, but if it was cooked then it probably wouldn't have helped anyway.

Edited October 28, 2013 by Norlig

[Norlig 1]

I changed the MAF out with another one, and it behaved identical, RPM still going up and down:

http://www.youtube.com/watch?v=KBcvcGoF5Jk

 

first part is with the MAF I have had for a year, the other one is with the one that was in use before that, but I am not sure if that one was broken as I dont remember if it helped changing it.

 

 

Could it be the Black plastic box that is mounted on the Throttle body, as commented in my video here: http://www.youtube.com/watch?v=XBp_nBOVLGo

Edited October 28, 2013 by Norlig

[alfizta 6]

yes, that's a possibility, the idle actuator. don't know which 6 clips he is talking about. mine is fixed with 3 torx t30 bolts next to the throttle body.

could you make a graph of lambda sensor signal and engine speed (rpm) simultaneously while you go to home/work? just to see if you can get a closed loop even it is just for a short period.

 

I have tested both my 146 and 156, and the discrepancy between desired air quantity and air quantity are similar to yours. Injection times were tested only on my 156, and are similar to yours too. Both my cars have lambda sensors working correctly.

[Norlig 1]

I got an idle actuator with Bosch #: 0 132 008 650, and VAL #: 972101.

 

I find other actuators with the same Bosch number, but different VAL numbers, I assume it will work as long as Bosch number is the same?, VAL number means something else?

 

Will this one work? http://www.ebay.co.uk/itm/Quinton-Hazell-Idle-Control-Valve-Alfa-Romeo-156-1-8-16V-T-SPARK-932A3-97-05-/190945528342?pt=UK_Motorcycle_Parts_13&hash=item2c753d8a16

 

Acording to this site, its the same: http://www.findpart.org/part/oe-46469916

 

 

I think it might be that, as its always act this way at the same position with the throttle pedal and most of the time when idling.

Doesnt explain the high fuel consumption when the Lambda was connected though.

Edited October 28, 2013 by Norlig

[alfizta 6]

we can only confirm that with chassis number.

and for that price I would only buy original bosch.

do you confirm fuel consumption was better with lambda disconected?

 

picture here looks like the one you are looking and it's bosch!

http://www.shop4part...=1026&sku=33092

 

alfa part number 71713829 links to an idle control valve, but not 100% sure if it is the same part as the bosch part you mentioned.

Edited October 28, 2013 by alfizta

[Smaky 73]

Check for continuity between pin 3 of the CAM sensor plug (blue) and pin 3 of the Idle control valve plug with the ECU main connector unplugged, the wires are both blue and there should be NO resistance also confirm continuity with pin 29 of the ECU plug from either of them if the test is OK.

[Smaky 73]

Plug A

 

[alfizta 6]

...and check the obvious, that is clean and well fastened

[Norlig 1]

we can only confirm that with chassis number.

and for that price I would only buy original bosch.

do you confirm fuel consumption was better with lambda disconected?

 

picture here looks like the one you are looking and it's bosch!

http://www.shop4part...=1026&sku=33092

 

alfa part number 71713829 links to an idle control valve, but not 100% sure if it is the same part as the bosch part you mentioned.

 

My chassisnumber is: ZAR93200001157895

 

 

Check for continuity between pin 3 of the CAM sensor plug (blue) and pin 3 of the Idle control valve plug with the ECU main connector unplugged, the wires are both blue and there should be NO resistance also confirm continuity with pin 29 of the ECU plug from either of them if the test is OK.

 

Thanks for the Very detailed description, I will get this done straight after work tomorrow.

 

I assume this will tell me if there are faults in the wiring that might cause the idle actuator to act this way.

Edited October 29, 2013 by Norlig

[Smaky 73]

 

 

I assume this will tell me if there are faults in the wiring that might cause the idle actuator to act this way.

 

Yup

[alfizta 6]

alfa part number confirmed 71713829 for bosch 0132008650

but make advised checkings before spending more money

good luck!

[Norlig 1]

Can't get the connector to the idle actuator off. can't feel what to click or flip to unhook it =/

Edited October 29, 2013 by Norlig

[alfizta 6]

once I got mine off, but had to undo the 4 bolts securing the Throttle body first...