Poor idle and I've done everything! VR6

[jekel 10]

Let me know how you get on :thumbleft:

 

 

 

Deffo change the blue temp sensor if not alread done, there like a tenner and take seconds to change (you'll lose a bit of coolant but like cupful if quick). I had 2 both reading bout the same but turned out both were equally wrong, new one sorted (don't assume because have 2 and same there ok the lesson there).

 

As a result however I have 3 perfect Bosch ISV's, I'm keeping one as a spare and was gonna ebay one, so if anybody needs message me. One's Corrado VR6 one's off a Lotus Carlton (identical bar inlet and outlet's are same size on that and as result gives stronger tickover I'd say, especially on uprated engine it was also brand new few months ago so I'll be keeping that one I think).

If it's just occasionally dying at initial tickover, after had foot down, could well be temp. sensor, that's what mine waa doing, blokes who was jumping all over place, up to 1500 sounds like could well be ISV.

[John Blount 11]

Deffo change the blue temp sensor if not alread done, there like a tenner and take seconds to change (you'll lose a bit of coolant but like cupful if quick). I had 2 both reading bout the same but turned out both were equally wrong, new one sorted (don't assume because have 2 and same there ok the lesson there).

 

As a result however I have 3 perfect Bosch ISV's, I'm keeping one as a spare and was gonna ebay one, so if anybody needs message me. One's Corrado VR6 one's off a Lotus Carlton (identical bar inlet and outlet's are same size on that and as result gives stronger tickover I'd say, especially on uprated engine it was also brand new few months ago so I'll be keeping that one I think).

If it's just occasionally dying at initial tickover, after had foot down, could well be temp. sensor, that's what mine waa doing, blokes who was jumping all over place, up to 1500 sounds like could well be ISV.

 

What do you mean by both were reading the same? Do you mean you had two blue sensors that we reading the same that were faulty so you changed it for a third one and it worked?

[[email protected] 10]

How much do you want for the ISV Jekel ? Regards Scott (rchijo)

[seanl82 23]

Think that was aimed at me from jekel. I have vcds and monitored both from stone cold, and was getting the same temp (around 10 degrees iirc. The original one rose in temp on vcds in line with temp gauge on the dash so pretty sure its good.

[buttles 0]

If your still not sure if the ISV is working or not you can check it's motor with VCDS. There's a test mode that runs through all the bits the ECU controls

[John Blount 11]

If your still not sure if the ISV is working or not you can check it's motor with VCDS. There's a test mode that runs through all the bits the ECU controls

 

Thanks Buttles, I didn't know you could do that and I've just found out how to do it and I can hear it opening and closing which would suggest it's working Ok!!

 

I've got a blue temp sensor on order to try as suggested, I'll let you know how I get on.

[jekel 10]

What do you mean by both were reading the same? Do you mean you had two blue sensors that we reading the same that were faulty so you changed it for a third one and it worked?

 

Yep exactly that, you can test the ohms with a multi meter, will change for diff. temps. but unless you've got an accurate thermometer too not a definite science and small diff. can make big diff. to car, so far price they are, and for dif they make I'd just get new one. Most places will stock fairly common across VW range

[John Blount 11]

Yep exactly that, you can test the ohms with a multi meter, will change for diff. temps. but unless you've got an accurate thermometer too not a definite science and small diff. can make big diff. to car, so far price they are, and for dif they make I'd just get new one. Most places will stock fairly common across VW range

 

Thanks for the advice, I've ordered all new...

[seanl82 23]

How do you get to the test mode John? Not seen that and if I'm honest, I haven't been through too many of the functions.

[John Blount 11]

How do you get to the test mode John? Not seen that and if I'm honest, I haven't been through too many of the functions.

 

Sean, go into engine then in the "advanced functions" box on the right hand side you will see "output tests" click this and you can scroll through the injectors, ICV, charcoal filter and a couple of others.

 

When I tested the ICV I could hear it opening and closing

[seanl82 23]

Ok I'll give it a try tomorrow, thanks John! :thumbleft:

[jekel 10]

Thanks for the advice, I've ordered all new...

 

New temp sensor much improved mine, but yesterday still died couple of times after been stuck in traffic for while then running fairly constantly for a mile then stop again, just that initial lift off, plus mpg improved but not to where it was. So last night disconnected lambda and today perfect on same journey, no revs dying any circs. It'll go better again with new Lambda but they will run without any obvious faults without lambda if everything else ok.

Lambda was only a year old but wasn't VW/Bosch (ordered a Bosch one but got palmed off with a FAE or something when turned up to collect from Europarts. Ordered an original VW (Bosch) one now from VW, .

So:

 

a) though most common not always the ISV

b) could be combination of things

c) careful where you buy Lambda's from, probs. one of those bite the bullet and go to VW ones

 

My idle was only ever that initial dying after revs. if jumping all over place, or stalling constantly ISV probs still fave.

[John Blount 11]

New temp sensor much improved mine, but yesterday still died couple of times after been stuck in traffic for while then running fairly constantly for a mile then stop again, just that initial lift off, plus mpg improved but not to where it was. So last night disconnected lambda and today perfect on same journey, no revs dying any circs. It'll go better again with new Lambda but they will run without any obvious faults without lambda if everything else ok.

Lambda was only a year old but wasn't VW/Bosch (ordered a Bosch one but got palmed off with a FAE or something when turned up to collect from Europarts. Ordered an original VW (Bosch) one now from VW, .

So:

 

a) though most common not always the ISV

b) could be combination of things

c) careful where you buy Lambda's from, probs. one of those bite the bullet and go to VW ones

 

My idle was only ever that initial dying after revs. if jumping all over place, or stalling constantly ISV probs still fave.

 

Interesting.... I've picked up all new temp sensors today and I'll fit them tomorrow so I'll see what happens!

 

What your saying about the lambda sensor is that only use a Bosch or OE VW one which make sense when it. plays such a vital role so I'll keep that in mind. I'm having my car Terra Cleaned on Saturday so hopefully this might freshen a few things up including the Lambda.. Hopefully!!

[VW_OwneR_85 2]

Interesting.... I've picked up all new temp sensors today and I'll fit them tomorrow so I'll see what happens!

 

I don't think it will make any difference as the temp the ecu is getting {which is the important one} which you got via vcds seems fine, unless its staying at 10 degrees when its hot, how is the car driving/running? is it purely just an idle problem?

[John Blount 11]

I don't think it will make any difference as the temp the ecu is getting {which is the important one} which you got via vcds seems fine, unless its staying at 10 degrees when its hot, how is the car driving/running? is it purely just an idle problem?

 

Purely just idle, fine once warm after a couple of minutes..

[VW_OwneR_85 2]

weird how its temp related but doesn't seem to be, have you checked the wiring to the ISV for splits/breaks and the plug for corrosion?

[John Blount 11]

Only when I changed the ISV but I didn't look that closely but I have checked it's opening and closing in the test function using VCDS and I can hear in operating.

 

There's no air leaks that I can see and I've sprayed the whole area in carb clearer and the engine note never changes so I can pretty much say that's not the issue.

[VW_OwneR_85 2]

I recon look a little closer at the throttle body, even though you cleaned it..

[John Blount 11]

I've replaced the all the water temperature sensors this morning and it's made no difference what so ever.

 

Still really poor idle for around a couple of minutes where it wants to stall if you don't keep the Rev's up after that it's fine.

 

As VW_Owner_85 says I'm thinking it could be the throttle body or the MAF and even the Lambda? Any way I can narrow it down a bit??

[dr_mat 0]

The lambda is not used at all until the engine reaches operating temperature.

 

I assume you can see that the engine is reaching temperature in VAGCOM/VCDS and you have been able to verify that all temperature sensors are working properly. If not, that's still the obvious answer. Note that the ECU will auto-calibrate the sensors to some extent, but one that's wildly out of range (though "working") may not actually, "work"..

[jekel 10]

Interesting.... I've picked up all new temp sensors today and I'll fit them tomorrow so I'll see what happens!

 

What your saying about the lambda sensor is that only use a Bosch or OE VW one which make sense when it. plays such a vital role so I'll keep that in mind. I'm having my car Terra Cleaned on Saturday so hopefully this might freshen a few things up including the Lambda.. Hopefully!!

 

Yes, wish I'd never changed mine, renewed everything bout year ago, sure old Lambda was fine, and didn't look that old, and proper VW/Bosch one, but there normally seized in, got to take the cat (or in my case now decat) pipe off and heat up to get out, I cut the wires to get a socket on as had new one, and threw it, otherwise I'd just put old original one back on. I'm dubious of these Bosch one's on Ebay as they seem to fit just bout every car out there if you believe them but the correct Bosch one fits VR6 and very few others I think, hence VW.

I doubt it's your Lambda from symptons, not same symptons as mine, it does'nt kick in at all for first 15 secs I think so wouldn't make sense. Easily checked, disconnect it, if it runs same or worse disconnected it's not working right.

The car should run fine without it, it like fine tunes the mix etc. I think, but it will default without it and run OK but not perfect, should'nt be any stalling. bad idle or anything major without.

What's the MPG on the dash computer, good, bad, changed recently?

[John Blount 11]

I did notice that the coolant temperature on VCDS was higher than the dash gauge ( VCDS was in the mid 80's and the dash gauge was just below 70) so I don't know if this has any relevance?

 

What I did prior to fitting them permently was to plug all 3 new coolent sensors in while the engine was stone cold and just leave them loose hanging on the wiring and then start th car, this made no difference and it is the same as it always is.

[VW_OwneR_85 2]

I did notice that the coolant temperature on VCDS was higher than the dash gauge ( VCDS was in the mid 80's and the dash gauge was just below 70) so I don't know if this has any relevance?

 

What I did prior to fitting them permently was to plug all 3 new coolent sensors in while the engine was stone cold and just leave them loose hanging on the wiring and then start th car, this made no difference and it is the same as it always is.

 

im thinking throttle body because every things working and driving fine, if it was maff or vac leak or coil pack etc etc it would also effect how its running/driving, fyi I probably shouldn't of said to compare dash gauge to ecu temp when hot as corrado dash gauges do have the tendency to read lower then what it actually is, I think the best bet it to try a different known working TB...

[buttles 0]

The only thing that can really go kaput with the TB is the position sensor. Assuming it's clean. Again you can use VCDS to see if it shows a smooth increase in degrees open as you put your foot down on the pedal. It won't show 100% when open, that's normal. Try cold and hot, of course with engine not running!! I had a cam position sensor go bad and not show on VCDS. On my third one now since new so they do go bad.

[seanl82 23]

I picked up a blue temp sensor today from TPS, pretty sure mine is good but worth a try. Black is just fan speed 3 and yellow was almost £40 and is for the dash gauge so didn't bother with those two. I'll see how I get on but not holding my breath. My TB was off about 2k ago with an engine clean and light refurbishment, so isn't gunked up or anything. Angle increase was also steady with throttle on VCDS although a little slow to react, but I imagine thats normal.