Idle - isv, maf, tps, tb cleaned, readings .. what next!

**Keyo** · 1 Week Ago

Thanks for the replt Fend anything that saves the coppers is more then welcome as the VGI is still on .

**pfnsht** · 6 Days Ago

Okay managed to spend some time working through the list.

1. MAF cleaned and tested with multi-meter - think it is okay - I'm seeing a reading fluctuating between 0.85v to 0.9v on idle. There is a perm 12v source to the MAF as well.

2. Took of TPS and sprayed electrical contact cleaner on it.

3. Carried out ECU reset procedure and read the basic settings, after driving it is a little better on idle.

4. Took all my vacuum lines off, inc. carbon canister and inspected carefully for cracks. No problems there.

5. Plugged in my OBD11 device and monitored the live readouts (there are no engine fault codes):

- I found my idle speed sits mostly at 680 rpm but drops to 640 and up to 720 rpm every couple of seconds.

- Coolant temp is good - steady 87 degrees

- Lambda value fluctuates around 1.0 which I think it normal.

Things I am not sure about:

- Injector timing is 3.3 to 3.7ms. I've seen references it should be around 1.5ms reading around forums?

- The EGR temp jumps between 182 degrees to 217 degrees centigrade every 1 second (I didn't think I had an EGR valve and maybe this is coming from the O2 sensor?)

- The timing should be +-1 degree of 6.0. Mine jumps 4.5 to 6.8

So I think maybe something is wrong, although it did get better following the ECU reset procedure. Just thinking out aloud

- if the temps are coming from the o2 sensor perhaps it is over fuelling due to a bad injector, which probably points to why it's backing off the timing to 4.5 degrees every second too.

- Motor mounts are worn and letting too much vibration through. If the numbers above look normally this could be a possibility.

Any other ideas

Thanks,
Matt

**Keyo** · 6 Days Ago

Originally Posted by pfnsht

Okay managed to spend some time working through the list.

1. MAF cleaned and tested with multi-meter - think it is okay - I'm seeing a reading fluctuating between 0.85v to 0.9v on idle. There is a perm 12v source to the MAF as well.

2. Took of TPS and sprayed electrical contact cleaner on it.

3. Carried out ECU reset procedure and read the basic settings, after driving it is a little better on idle.

4. Took all my vacuum lines off, inc. carbon canister and inspected carefully for cracks. No problems there.

5. Plugged in my OBD11 device and monitored the live readouts (there are no engine fault codes):

- I found my idle speed sits mostly at 680 rpm but drops to 640 and up to 720 rpm every couple of seconds.

- Coolant temp is good - steady 87 degrees

- Lambda value fluctuates around 1.0 which I think it normal.

Things I am not sure about:

- Injector timing is 3.3 to 3.7ms. I've seen references it should be around 1.5ms reading around forums?

- The EGR temp jumps between 182 degrees to 217 degrees centigrade every 1 second (I didn't think I had an EGR valve and maybe this is coming from the O2 sensor?)

- The timing should be +-1 degree of 6.0. Mine jumps 4.5 to 6.8

So I think maybe something is wrong, although it did get better following the ECU reset procedure. Just thinking out aloud

- if the temps are coming from the o2 sensor perhaps it is over fuelling due to a bad injector, which probably points to why it's backing off the timing to 4.5 degrees every second too.

- Motor mounts are worn and letting too much vibration through. If the numbers above look normally this could be a possibility.

Any other ideas

Thanks,
Matt

Have you tried a good old bit of injector cleaner like redex or something like that and give it a good run between 4.5 and 5 revs for a few minutes , you never know .

Also can you get someone to rev the engine have a look under the car at the exhaust where it meeets the catalytic and see if there is any smoke leaks around that area. Just saying that because had those symptons what you have mentioned and today I noticed a smoke leak where the exhaust meets the cat area, and after the last couple of months checking VAG fault codes every other day it finally threw up code 00537 Oxygen sensor regulation sporadic and 00561 mixture which I expected as the cat and O2 sensor have never been changed. The O2 sensor apparently dont show a fault unless they are totally bad.

Thankfully I have these ready to fit .

EEC Catalatic (British made)with fixing kit

https://www.ebay.co.uk/itm/Fits-VW-C...72.m2749.l2649

Bosch O2 sensor for late model VR6

https://www.ebay.co.uk/itm/BOSCH-Lam...72.m2749.l2649

Solennoid charcoal vavle just incase is stcking open (second hand new ones are £120 plus wow !!!)

https://www.ebay.co.uk/itm/BOSCH-028...72.m2749.l2649

**pfnsht** · 6 Days Ago

Thanks for links Keyo

I believe I do have a very minor exhaust leak up front, notice it once the engine is warmed up. Planning a stainless system for it at some point so quietly ignoring the problem at the mo!

I've tried the injector cleaner but I suppose a more concentrated mixture wouldn't hurt.

**Keyo** · 6 Days Ago

A leaky exhaust and bad lambada = rough running engine bad mixture.I could see the heat gasses escaping from the cat on mine to today quite prolific so I reckon that could give the sensor a crooked reading could be wrong though.

Found these guys really sound and the cheapest for Milltek Catback.

https://www.milltekexhaust-roadrunnermotorsport.co.uk/

Just to add might aswell do the down pipe if doing the rest of the exhaust system, can get one for £65 with gasket and bolts from BM catalsyt (British Manufacture) it would be rude not to.

I had a good look at the EEC Cat earlier and it seems well made also the Bosch sensor screws into the housing spot on.

**Jim Bowen** · 5 Days Ago

Does it change with any electrics on? Like hazards and full beam? I had an issue not long ago where the revs would pulse with the hazards and change the revs when full beam was on. Was my alternator needed servicing

**pfnsht** · 5 Days Ago

CHeers Jim. Oddly the car seems to be behaving much better most of the time since the work (mostly just cleaning).

I did have a go at popping all the electrics on and idle seems fine.

I think i am left the characteristic very very very slight lumpy idle.

I’ve got some injector cleaner to run through but if it remains as is I’ll be happy.