VR6 ongoing running problems . . . .

[theRuler 0]

ok i have had this problem for a good year now. attempts to fix it have been unsuccessful. here's the deal.

 

the car starts from cold fine.

it doesnt always tick over that great, and sometimes on the way to work it may stall when hit the clutch at a junction.

 

this is where the problems kick in . . . .

 

after a stall it takes a load of turns to start. when it does start (after i look like a chump in the traffic) it runs like crap. anything below 2000 revs is worthless. when i press the throttle it misfires (not great for pulling away). if i drive in 5th at about 2000 revs it kangaroos like mad. this eventually smooths out. if i am stuck in traffic though, its a nightmare.

 

now i have tested this, by driving along (while its working fine) then switching off the ignition, and switching it back on. the misfire starts immediately. getting petrol is a nightmare, as i am "old ma revs" pulling off the forecourt (just so the smegger doesnt stall again)

 

i have changed plugs / leads, tested my airflow meter on a different car, had the lambda thingy tested, all to no avail. what makes it worse is when i have taken it somewhere to be looked at, it has performed fine :mad:

 

after i restart it after a stall, the tickover bounces from 500 to 1500 revs. revving itself.

 

any thoughts? the car has done 150k

[Kevin Bacon 5]

My immediate thoughts are the idle valve and Coilpack.

 

Have you done the water spray at night trick yet? You only need 1 or 2 plugs to get a weak spark to cause poor running.

 

The idle valve could be causing your prolonged starting and most likely the 500 to 1500 hunting also. Might be worth cleaning that fellow out with the old carb cleaner.

 

Oh has it been VAG-COM'd?

 

I've scanned a number of VR6s recently and they ALL had a cam sensor down.....

[theRuler 0]

i took the idle valve off and cleaned it, it didnt really make any difference.

maybe it is a bit shagged, hence why i get the stalling.

 

what i dont understand is that it will run ok until i switch it off and back on (whilst rolling) then it goes to smeg. (doing this simulates a stall)

 

it hasnt been vag com'd.

 

if i knew for sure it was the coilpack i would change it. but the way it is now, i could start it up from cold, and it would run for hours. if i start it up, then switch it off, then back on it goes into undrivable mode.

 

i only use this car to make the 12 mile journey to work, as it is too unreliable for any other use (we tend to use my gf's polo valver)

[Kevin Bacon 5]

Done the ignition switch yet?

[dr_mat 0]

Temp sensors could be iffy maybe? Maybe the cold start is ok because the ECU always thinks the engine is cold? You can check the sensor values using VAGCOM too.

[theRuler 0]

could be temp sensors i guess. then when its warm the ecu doesnt know it is and keeps the cold start running, making it all go wrong?

i think i need to do the vag com deal. its about 50 quid at the vw garage in stafford (which is incidently 5 mins walk from where i live)

[Reggit 0]

I could vagcom it for you, as I can get myself to Stafford during work time if I arrange my work suitably.

 

There has to be a BUT hasn't there?

 

I only have a 2x2 connector whereas you probably have OBD2.

 

Can you verify which connector is fitted to your car? It's under the gear surround.

 

corradovr6sc is near you I think with OBD2 vagcom, he may be able to help.

 

See this thread for vagcom info.

[dav 0]

theRuler,

 

It seems like your problems are very similar to what i was experiencing with mine, i changed a hole load of parts and in the end it turned out to be the Fuel pump and the Coil, mine is "dizzy VR" but i suppose the fault still applies. After i changed the fuel pump it ran fine for a few days and then it started to play up again, after changing the coil it has been running really good but i recon that’s also down to the amount of parts that have been replaced.

 

When I did get it Vag-com’ed it showed no errors, but it could very well be different for you, get it checked as soon as possible, could save you a great deal of time, money and frustration.

 

D.

[Stroller 0]

Thank goodness I have found this site!

 

I have had almost exactly the same problem starting in October last year. At this point the the rpm was all over the place. The guy who looks after the car put it on his computer and fitted a new Idle Stabilisation Valve (I think).

 

Everything was much better untill about a month ago, when the car started to cut out out under braking and depression of the clutch. The accelerator also developed a flat spot from rest, and you almost have to slip the clutch to avoid stalling. The codes indicated the Lamda Sensor and the Engine Speed Sensor. The Lamda Sensor was replaced about two weeks ago, only for the problems above to appear:

 

"the car starts from cold fine.

it doesnt always tick over that great, and sometimes on the way to work it may stall when hit the clutch at a junction.

 

this is where the problems kick in . . . .

 

after a stall it takes a load of turns to start. when it does start (after I look like a chump in the traffic) it runs like crap"

 

The problem got much more intermittent, but it still hadn't gone away, so I had it checked again, and the code for the Engine Speed Sensor came up, so on Thursday that was replaced, thinking all my problems would be solved.......

 

I still have the flat spot on the acceleartor from rest, almost as if there is a blockage or the engine is choking momentarily, and last night it stalled on me twice! Great!

 

From this thread I have picked up: Coil Pack, Fuel Pump and Temp Sensors.

 

Elsewhere I have picked up that the idle problem can be caused from the vac hose (7mm smooth rubber one on right side of engine) that purges the fuel vapor canister. It is formed like an "s" and melts on the manifold.

 

For a while now I have had an intermittent petrol vapour smell (mainly from the boot), so I am thinking that may be this could be the problem?

 

Also:

 

Check the throttle body for binding, and the cable. Follow the cable from the pedal to the throttle body, look for fraying or binding at the guides

 

and

 

could the sensor inside the distributor not be working properly?

 

My immediate thoughts are:

 

1) I need to VAG COM the car? What is the difference between this and the diagnostic codes that my mecahanic is getting out (I am assuming he hasn't got VAG COM)

 

2) Would any kind person in Surrey who has the kit be prepared to VAG COM the car for me? I have checked, and it is a 16 pin, even though it is an L Reg 1994.

 

3) Can anyone recommend to me a local VW Specialist in Surrey (not a main dealer), who would be able to look after such tricky problems as this, and stop me from going bankrupt?

 

Any ideas on the best way forward from here, everyone?

 

Thanks very much!

[dr_mat 0]

VAG-COM reads the same engine diagnostic codes as any other code reader, but is more advanced - you can read out values from certain sensors on the engine in realtime - such as the temperature sensors, lambda value and so on.

[theRuler 0]

yo stroller, i know what you mean about chnaging stuff that "fixes" this.

 

i changed the plugs. YAY all fixed. couple of days later back to uncool runnings.

 

then i changed the leads. all fixed. for a day

 

i fixed a fuel leak. all fixed. for like an hour tops.

 

i have pm'd a request to corradovr6sc hopefully he can "vagcom" me and maybe we will get the root of the cause.

 

i have the later type old birty dastard 2 style connection

[Supercharged 2]

For a while now I have had an intermittent petrol vapour smell (mainly from the boot), so I am thinking that may be this could be the problem?

 

May be worth taking the fuelpump access cover off and check the pipes, also the ones to the filter under the car - have you cleaned behind the rubber boot round the filler neck?? - If never then do it asap!

[theRuler 0]

ok i think i am fixed now.

thanks to ben (corradovr6sc) and his vag com. the fault it picked up straight away was the blue coolant sensor.

 

we have a look under the bonnet

 

the blue sensor is identified

 

the blue sensor plug is NOT ON RIGHT :oops:

 

hot damn. it must have not been on right since i had the head gasket changed 18 MONTHS ago.

 

now the plug is firmly rammed in the car runs right again. 8)

this is somewhat of an epiphany, after all this time of my car running lumpier than a bed full of marbles.

 

now when the car is stalled / switched off, when it starts back up the idle goes to about 650 - 700 rpm. you'll notice when you start your car from NOT cold, the revs, within seconds, settle at the required tickover (depending on the engine temp).

 

well with that blue sensor not connected right (or maybe it wasnt even connected at all) the tickover didnt know where it should be, nor did the fuelling know what to do. so the revs never settled.

 

i am chuffed

[2cc 0]

Glad to hear that m8.

Sort of same topic, mine is often 'slightly reluctant' to start when at normal operating temp. Cranks fine but doesn't fire. A dab of throttle and then held about a third open before cranking and she usually fires up ok (but have to get out of the throttle pdq else the revs go up the clock real fast).

Changed my blue temp ages ago as was suggested as cause but made no difference. Kind of used to it now but wonder if anyone else gets this?

[Kevin Bacon 5]

Dinkus had that on his but we couldn't find a cause....although changing the fuel filter seemed to reduce the cranking time....still took far longer than normal to fire up though.

 

Mine always starts instantly when cold and and about a crank and a half when hot... I was going to say fuel pump but I know you've had fun and games with that already....hmmm, dunno mate!