What work did you do on your car today?

[payaya]

Changed my radiator! Onto my third one! Biarch!

[Daniel2019]

Diagnosed a blown head gasket on a mate's car with the help of lawso (contrary to assumptions - lawso didnt actually blow the head gasket, he helped us figure out that it was blown!)

You only learn from experience

Something like that had to be said.. standard.

[ObsidianRadio]

Diagnosed a blown head gasket on a mate's car with the help of lawso (contrary to assumptions - lawso didnt actually blow the head gasket, he helped us figure out that it was blown!)

You only learn from experience

Something like that had to be said.. standard.

[fraz91]

12:1 Forged Goodness has arrived. VRS kit arrived as well. Now to finish stripping the motor down

[AJ]

Had a chat with Dan and we came up with a few other things that might be effecting mine.

1. ECU
2. Gear Box computer
3. MAF sensor/controller

Thoughts?

How easy is it to 'borrow' some of these parts to test against mine to see if that fixes it?

Anyone got any spares?

Thanks.

[payaya]

Had a chat with Dan and we came up with a few other things that might be effecting mine.

1. ECU
2. Gear Box computer
3. MAF sensor/controller

Thoughts?

How easy is it to 'borrow' some of these parts to test against mine to see if that fixes it?

Anyone got any spares?

Thanks.

What's wrong with your car?

[Astron_Boy]

Had a chat with Dan and we came up with a few other things that might be effecting mine.

1. ECU
2. Gear Box computer
3. MAF sensor/controller

Thoughts?

How easy is it to 'borrow' some of these parts to test against mine to see if that fixes it?

Anyone got any spares?

Thanks.

Yeah, the more I think about it, the less I'm leaning toward Geabox ECU.

I dare say the MAF to be the prime cause, and then blame the ECU.
Simply as it's doing the same thing the Mercs do when they have a dirty/ faulty MAF.

[payaya]

What is it doing? Shifting funny? Idling funny? What??

[AJ]

Idling very poorly when in gear.

[payaya]

Idling very poorly when in gear.

Have you checked your rear lower engine mount? What RPM is it revving at at idle when in drive? Did you have your timing belt changed recently or its always had a bad idle? Are the RPMs fluctuating?

You can basically rule out the ECU and TCU. Pull the plug on your maf and see if it runs better.

I'll say your rear mount, You cannot see if its stuffed by looking at it, you need to loosen the bolts going to the centre member as it breaks at the bottom. How close are your belt housing bolts to the centremember? Bet ya it's only tiny. The bolt that goes through the front and rear mount should be directly in the centre of the bush, bet yours in about 1cm off centre towards the bottom. It cant be the ECU, TCU or Maf as it's only in drive.

Let me guess when your thermos switch on while idle you can feel a vibration through the car? This should not be. When you drive under load say up a hill in third gear you can feel a vibration through the car? Even accelerating at low speeds in 3rd gear you can feel it?

[AJ]

Idling very poorly when in gear.

Have you checked your rear lower engine mount? What RPM is it revving at at idle when in drive? Did you have your timing belt changed recently or its always had a bad idle? Are the RPMs fluctuating?

You can basically rule out the ECU and TCU. Pull the plug on your maf and see if it runs better.

I'll say your rear mount, You cannot see if its stuffed by looking at it, you need to loosen the bolts going to the centre member as it breaks at the bottom. How close are your belt housing bolts to the centremember? Bet ya it's only tiny. The bolt that goes through the front and rear mount should be directly in the centre of the bush, bet yours in about 1cm off centre towards the bottom. It cant be the ECU, TCU or Maf as it's only in drive.

Let me guess when your thermos switch on while idle you can feel a vibration through the car? This should not be. When you drive under load say up a hill in third gear you can feel a vibration through the car? Even accelerating at low speeds in 3rd gear you can feel it?

No, not checked the engine mount.
The revs drop so low that it almost stalls when in drive and not moving, say at the lights for example. Less than 500 rpm.
The car shudders and the dash lights flicker in time with the shuddering, as if going to stall.
Not had the timing belt changed in the time I've had the car (2 years), this issue only showed up after coming home form a track day.
Yes, rpm fluctuates when stationary. They drop suddenly and continue to drop until it stalls. Once I'm moving it's fine. No issues up hills or under load that I can recall (not driven it for about 3 months).
Not noticed anything when the thermos kick in.

Why would the rear mount make it stall in D?

[payaya]

Ah didn't know it stalls. What were the rpms when warm in park or n? Over 1k?

Where does the rpm needle sit when idling? In the middle of 0 and 1000??

Does it stall in N or P? When you turn your car to the "on" position without starting the engine do you hear a buzzing noise for about a second?

[AJ]

No, doesn't stall in N or P. revs used to sit normal, around the 800 mark. Verious 'mechanics' turned the idle up, trying to fix it. In D it would still shudder, but in P it would be at almost 2k.

[payaya]

Did your rpm drop when your AC was turned on or stayed the same? Where was the needle sitting between 0 and 1000 at idle?

[PHIL069]

@ AJ, I had the same problem with an earlier owned car I had to hold down the accelerator pedal a bit when stopped at lights. It would stall in D but idle in P. It ended being clogged injectors. Got injectors professionally cleaned, problem fixed.

[payaya]

@ AJ, I had the same problem with an earlier owned car I had to hold down the accelerator pedal a bit when stopped at lights, and it ended being clogged injectors. Got injectors professionally cleaned, problem fixed.

He essentially is holding down the throttle by adjusting the throttle screw.

So why is the injectors causing the rpm to surge up while in N and P?

The reason why I ask this before I knew you exibited this symptom is because with certain cars and especially the FTO, they surge past 1k when in P and N. The reason it's going to 2k in P and N is mechanics have either adjusted the biss screw or idle screw to compensate for rpms in drive and by doing this is makes the issue even worse in P and N.

I'm guessing you have a stepper motor with the brown backing? These are known to be bad with the heat. So track day would have fried it and that's why you are having stalling issues. Even if you do the stepper coil test and it is within specs it still can be stuffed. Could be an issue with the wiring but I highly doubt it.

Pull your stepper connector and go for a drive, bet ya the car won't drive any differently. If it is working pulling it will make the car run like sh*t.

[Astron_Boy]

Not the stepper motor.
We've already done that one!

Personally, I don't think it's fuel related.

This is the problem however, it's all deduction, it really could be anything, and the list simply has to be deduced from most obvious to least.

MAS I dare say is easiest to test off the bat.

EDIT: MAF to MAS, just remembered that.

EDIT 2: I'm kind of now steeping back from even that, given it's not consistent from Park to Drive, and is only giving dramas when in Drive....

[King hit kiz]

New windscreen fitted on all for $200

And got some veilside skirts that just need a re-spray

[payaya]

Not the stepper motor.
We've already done that one!

Personally, I don't think it's fuel related.

This is the problem however, it's all deduction, it really could be anything, and the list simply has to be deduced from most obvious to least.

MAS I dare say is easiest to test off the bat.

EDIT: MAF to MAS, just remembered that.

EDIT 2: I'm kind of now steeping back from even that, given it's not consistent from Park to Drive, and is only giving dramas when in Drive....

Did you disconnect it and run the car without it? Did you use a proven to be good stepper? Did you check the connector if the pins were good? Did you check the harness for continuity?? Did you trace the harness back to the ECU.

Changing a stepper is one thing but I am almost certain the problem lies in the stepper motor. I did not even know it had an idle surge in P and N and only a bad stepper will cause this.

I bet you don't hear a clicking, buzzing type noise when the ignition is on.

Bet ya it doesn't idle up during a cold start and goes strait to the warm idle speed strait away.

The ECU is also known to burn part of it out if you run without a stepper sometimes but very rare.

A air flow meter will cause all sorts of issues while driving. You will see black smoke come out of the exhaust from it running rich. Disconnect it see if it runs any better!

Try this for a test, whoever has a good FTO pull the plug to your stepper and I can almost guarantee your idle will surge in P and N, drop really low in rpm and sometimes stall.

[AJ]

We took the stepper out of mine and put it in Dans and his car actually ran better that it had with his old one, in fact, he's still got mine in his car. I put a new one on mine and the issue is still there.

Sometimes the issue isn't there until the car is warm, sometimes it does it from cold...very random. Its when you you engage a gear, reverse also has the same issue.