Advice on lumpy, erratic 2.0 16v - being a bit crap again..

[Lippy 0]

Jim, your not talking to yourself mate - mine is still being a stubborn little git, but intermittetly as you say - showed it to my mechanic friend and it behaved perfectly!

 

grrrr!

 

I don't want to spend money on xyz only to find out they haven't made a difference

[davidwort 0]

Revs seem even more bouncy now at idle. I think reusing the old gaskets was a mistake.

 

I think i might start saving up to go the whole hog - new injectors + seals, gaskets, ISV, HT leads, etc.. would cost a few hundred quid but I think it'd totally transform the way the car run.

 

And here I am by myself, er, talking to myself. Now thats chaos theory..

 

Jim, I'm no expert on K-jet or KE-Jet but your manifold gasket issue perhaps gives some clues.

you could try spraying some Carb cleaner or WD40 around the inlet manifold and vacuum hoses to see if there's a vacuum leak somewhere. It would also be an idea to try and get it idling on a CO meter to see if the CO is fluctuating.

It does seem to point to an air/fuel thing rather than electrical and you've just got to cross things off one by one from the cheapest upwards.

If you can take the outlet to the airbox off and pull up the air flap, check to see if it's moving freely and not sticking anywhere, make sure all the vac hoses are good and if at all possible swap some senders over with another car temporarily.

does it pull smoothly and up to the red line?, are the idle problems exactly the same with a hot and cold engine?

Bit more hassle but checking the injector spray patterns would be worth a go too.

I'm gradually scanning the Passat Manual and will send you a PDF when it's done, if you can give me as detailed as possible a description of all the problems (pm?) I'll forward it to my dad who worked on K-jet VAG cars at GTI Engineering for about 15 years, it's always my last resort :)

 

David.

[Jim 2]

Hi David.. I could send you over a PM but the problems can be summed up fairly quickly.

 

One thing for the car is that it does seem to pull quite happily all the way through the revs to the red line with no obvious problems.

 

The problems seem to come at low revs and idling, and starting in the mornings... but as I say it just comes and goes as and when it feels like it.

 

This morning, for example.. turning the key it gradually spluttered into life after about 3 seconds of ignition. Then for the first minute or two of driving, idling is usually (but not always) really ropey.. revs drop to virtually cutting out (battery light flicks but then it catches and bounces back up to 900RPM or so.. then does the same) or sometimes it does just cut out.

 

Then it seems ok for a few mins of driving but coming up to a junction and dipping the clutch causes revs bouncing.. usually up and down between about 1000RPM and 450RPM'ish. And then even when the car is all fully warmed up, revs seem to noticably surge up and down at idle point.. can't be dropping up and down by much but enough to notice a small surge in the engine.

 

When driving in low revs the car can be fairly lurchy - like if you press part throttle its as if you're pressing the throttle on and off a bit.. but as I say, on Wide Open Throttle it goes like its just had a stick of dynamite stuck up the exhaust pipe.

 

I will look at changing those gaskets - they're something stupid like £3.50 for the upper inlet gasket and £2.50 for the lower inlet and one of them was really really knackered.. and its a pretty quick job to change them.

 

But would value your dads advice tho!

[Phil K 0]

Probably a stoopid question but, would the KR cam cause any of this?

 

I ask as am about to put one in mine...

[Jim 2]

I don't think its to blame. The rough idling has gradually developed since having the car.. it wasn't like this at all from the start.

[davidwort 0]

Hi David.. I could send you over a PM but the problems can be summed up fairly quickly.

 

One thing for the car is that it does seem to pull quite happily all the way through the revs to the red line with no obvious problems...

 

Ok, I'll have a word.

Reading a few Google searches for K-jet problems I've come to my own conclusion that you've got vacuum leak problems, that may explain the fact it goes fine at full throttle but gives the cruising and idle problems.

Injector 'O' rings often give idling problems especially when cold, again these are cheap and should be done to eliminate them.

when you do the 'O' rings that would be a good time to check the injector spray patterns too.

Again, the WD40 trick sprayed onto Vac lines and mainifold joins will show a rev change if it gets sucked in.

[davidwort 0]

Probably a stoopid question but, would the KR cam cause any of this?

 

I ask as am about to put one in mine...

 

not directly, but disturbing the manifold and vacuum lines may well be more than some of the old hoses and joints can take.

[Jim 2]

Hm ok... thanks for your thoughts mate :)

 

With regards injectors, do they literally just pull in and out of the inlet without too much fuss? What about the solid bits of injector line? I could simply buy four new injector clip things + new seals and new gaskets for the inlet manifold and that wouldn't break the bank.. and might eliminate this problem...

[Lippy 0]

can anyone take the time to list the things that they would change in order? I need to task my mate to organise mine, as seem to have similar problems but not the wide idling issues. From cold mine feels like it is driving through treacle but then seems to be OK

[davidwort 0]

Hm ok... thanks for your thoughts mate :)

 

With regards injectors, do they literally just pull in and out of the inlet without too much fuss? What about the solid bits of injector line? I could simply buy four new injector clip things + new seals and new gaskets for the inlet manifold and that wouldn't break the bank.. and might eliminate this problem...

 

yes and no :)

old hard O rings can be difficult to remove, best done on a warm engine, but they do just pull out, some cars have metal clips holding the injector into it's seat, slide/ping these off first.

Don't pull on the injector lines, they're not up to the stress! mole grips clamped around the injector can help, but it's difficult to get at, perhaps wait until you do your manifold gaskets.

I found soaking a bit of WD40 around the injector seats helped a bit, eventually they came out... POP!

You need the upper and lower seals, although just the bigger upper ones will probably be enough. They can be a bugger to get off the injectors when old and hard, I think the new softer ones went on fairly easily though.

I got two sets from VAG (of the big ones) as they couldn't count or something :roll: , so if you have trouble getting some give me a pm and I'll post them, pretty sure I've got four or five left. GSF should do them although some branches deny this :lol:

[davidwort 0]

One other thing Jim, a bouncing idle is a sign you ISV is OK, it's simply trying to keep the idle up.

[Jim 2]

Thats a good sign.

 

Well if I was going to change the upper and lower inlet manifold gaskets at the same time, it'd be a doddle getting at the injectors. And to be honest it wasn't a particularly time consuming process getting at that lot.. just undoing a few clips and a bunch of bolts.

 

I think I should look at picking up the appropriate Passat (with the 9A in it) Haynes manual for torque values when doing it all back up again..

 

I had a quick skim over the GSF site and they do seem to list upper and lower injector seals.. but I might just pick em up from VAG for peace of mind as I get to see it all exploded on the ETKA diagram rather than just going on blind faith at GSF! :)

 

Good news about the ISV too.. thanks for that :)

[davidwort 0]

can anyone take the time to list the things that they would change in order? I need to task my mate to organise mine, as seem to have similar problems but not the wide idling issues. From cold mine feels like it is driving through treacle but then seems to be OK

 

OK here's some, perhaps not in order though:

 

 

check all the ignition stuff, plugs leads, dizzy cap and rotor, hall sender (usually gives hot running probs first)

is the air filter clean?

check fitting and sealing of plastic intake sections from metering head to throttle body

is the crank breather hose attached to underside of intake pipe

check all vac lines are good and connected correctly, these run to ECU, MFA, brake servo, aux air valve and under throttle body, possibly more/different on KE-jet.

are all elec connectors to ISV, temp senders on head, Aux air valve etc in good nick and connected

check ISV buzzes when supplied with 12V, and it's clean

check manifold gaskets for leaks

check and clean throttle body air bleed screw

check idle switch on throttle body operates and is triggered at closed throttle

check air plate move freely and smoothly

check injector o-rings and spray pattern

check timing, both ignition and engine, has the belt jumped a tooth?

check system fuel pressures and delivery

replace fuel filter (under car by tank)

lamda probe OK?

CO analysis?

compression test

new metering head

rolling road setup

 

 

(following is for a version of K-jet, perhaps not KE-Jet as on 2.0L 16v)

for diagram attached:

 

Checkpoint ID

Checkpoint ID

1 - Fuel Pump

2 - Fuel Pump connections and supply

3 - Auxiliary Air Valve

4 - Fuel Filter and supply pipes

5 - Cold Start Valve

6 - Air intake system for leaks

7 - Airflow Sensor Plate and / or Control Plunger

8 - Airflow Sensor Plate position

9 - Thermo-Time Switch

10 - Cold Start Valve for leaking

11 - Injector Valves

12 - Control Pressure - cold

13 - Control Pressure - warm

14 - Primary Pressure

15 - Differential Pressure

16 - System Pressure

17 - Fuel System for leaks

18 - Vacuum System for leaks

19 - Throttle Valve

20 - Idle Speed and CO content

21 - Starting Enrichment function

22 - Correction function (diagnostic test / Ford)

23 - Post Start Enrichment function

24 - Warm Up Enrichment function

25 - Acceleration Enrichment function

26 - Full Load Enrichment function

27 - Throttle Switch Adjustment Impulse Module (if fitted)

[Jim 2]

Well just had a flick through my Lindsay Porter manual and it was a complete load of tosh.. doesn't even mention the inlet manifold at any point. Hm.

 

Scoured eBay and someone had the relevant Passat Haynes manual for £4.50 delivered! Sold! :)

[Jim 2]

Ok - been and bought upper / lower inlet gaskets, new injector seals and new springly clips to keep em in place (I seem to have three and they're all rusty and well past it)

 

Make sure you're sitting down though - I enquired about the price for the other temperature sensor (which feeds the ECU and connects with a two pin plug) and it was.. wait for it.. £70!!!!!!

 

I think the words i'm looking for are 'Daylight' and 'Robbery' - needless to say I left that alone and will come back to it if i'm still having problems later on.

[davidwort 0]

Ok - been and bought upper / lower inlet gaskets, new injector seals and new springly clips to keep em in place (I seem to have three and they're all rusty and well past it)

 

Make sure you're sitting down though - I enquired about the price for the other temperature sensor (which feeds the ECU and connects with a two pin plug) and it was.. wait for it.. £70!!!!!!

 

I think the words i'm looking for are 'Daylight' and 'Robbery' - needless to say I left that alone and will come back to it if i'm still having problems later on.

 

Jim, is that the thermo-timeswitch (043 906 163A), if so it's used on loads of golfs, audis and passats that have k-jet or KE-jet and 4cyl engines, plenty of those in scrap yards.

[Lippy 0]

i can't believe the guys at VW keep a straight face. Hopefully you could find some in a scrappy!

[Jim 2]

To be honest I think the parts guy gets embarassed at some of the prices sometimes.. he actually laughed when he read out the price!

[davidwort 0]

Jim,

finally got to speak to my dad about K(E)-jet problems,

he had a few questions to ask too, do the problems vary according to the level of fuel in the tank?, this would suggest fuel pressure/pump problems.

 

The only way to be sure is to connect the system up to pressure gauge, check the system pressure and monitor any fluctuations.

Some cars have a gauze filter in the fuel inlet to the metering head, for some reason this can give problems and can just be removed and thrown away.

The problems don't seem to be ignition, as a dud hall sender would just leave you with no spark or would fail to start near strong

 

radio/electro-magnetic emissions.

Any inlet vacuum leaks will give varying problems as we know, both revs and temperature will affect how severe the resulting bad running.

Injector O-rings, manifold gaskets, throttle body gaskets (only if they've ever been disturbed), the idle air bleed on the side of the trottle body,

 

the big rubber sections of inlet can get small splits, the small vaccuum hoses and their joints (T-pieces) all this stuff needs carefully inspecting

 

for damage, cracks and air leaks.

Hope this helps,

David.

[Jim 2]

Hm.. well that keeps it interesting!

 

I've not noticed any real variation depending on the level of fuel. What sort of behaviour should I be expecting at what levels of fuel?

 

I can't seem to get it to behave the same from one day to the next. Some days its really bouncy revs, sometimes its fairly solid - some mornings it wants to cut out and some mornings its not very happy but manages!

 

Going to Erics on Sunday along with my new gaskets and injector clip things and will see how I go from there. As previously mentioned, one of the gaskets is properly screwed and virtually fell in two pieces when we tried to refit but with no parts places open at 3pm on Saturday afternoon and this being my only car we had no choice but put it back and hope for the best.

 

Will have a darn good poke around when we're refitting to see if there are any obvious cracks or leaks in any of the vac hosing..

[CazzaVR 0]

Jim, my first valver had very inconsistent revs. Sometimes it would be bouncing around all over the place, and my local garage couldn't find the prob. Similar symptoms to yours when in traffic etc. After a good inspection, I noticed that one of the hoses to the ISV had a small split underneath, that was pretty much invisible unless looking v. thoroughly. Changed it and the car was completely cured. Worth a look.

[Jim 2]

Hm - thanks for that mate. Will have a good poke around when changing that gasket :)

[davidwort 0]

Hm - thanks for that mate. Will have a good poke around when changing that gasket :)

 

One more thing Jim, your car is pretty high mileage, so as well as the throttle body idle air bleed screw I'd consider taking the whole throttle body off and cleaning the whole thing thoroughly, including linkages, they can get mighty clogged up with oily gunk from the crankcase breather at high mileage.

[Jim 2]

Ok mate. I'll consult the Haynes manual for info on how to do that. Is it a long / difficult job?

[davidwort 0]

Ok mate. I'll consult the Haynes manual for info on how to do that. Is it a long / difficult job?

 

not really, take off the inlet pipe and the two vac hoses underneath, unclip the throttle cable and it's then basically just 4 hex head bolts holding the throttle body to the manifold, best undone with the right sized allen socket rather than struggling with allen keys though, couple of quid from Halfords and then you won't knacker the heads of the bolts :)