9a issue with timing - next issue

[easypops 8]

Throttle position switch (potentiometer) could be your problem....... it's the electrical part on the throttle body.........loads written on it, the search will help...........I would find them for you but no time at the moment :)

[bmwcompact 10]

Firstly, I am pleased to hear that the car is now running. I am not however clear what caused the breakthrough: at the end of the day was it a case of setting the valvetiming/cam belt fitting correctly?

 

As for your present running problem, I offer the following:

 

Cars that don't run well unless the tank is full usually have a failed lift pump in the tank. I've read lots of posts about this here and on other forums but have no personal experience of this. However I have removed the liftpump on my 9A to check its operation (my intank pump filter was clean). Its not difficult: 3 screws to remove the black plate in the boot, remove the electrical connection/remove 2 fuel pipe clips and pull off hoses, suitable drift and hammer to unscrew the large plastic cap from the tank and then remove the pump/fuel gauge sender unit. Its then easy to establish whether the pump is working. On refitting you will need 2 new hose clips.

 

Assuming you have got your timing right now, all 3 possibilities for the poor idling have already been given. Lets assume the fuel distribution meter hasn't been messed with and is OK since you say your car did run well for 5 months.

 

The ISV may be responsible for the idling problems. It can be cleaned with something like brake cleaner. Some have permanent success here, others temporary success. I have recently fitted a used one to my 9A (137K) after 2 attempts at cleaning which still left a somewhat temperamental ISV. Currently my idling is perfect. (The 9A has the same ISV as a VR6 either Bosch or VDO)

 

The throttle potentiometer causes lots of problems with the 9A. I personally replaced mine with a used one after intermittent problems early in my ownership. The potentiometer is not a true throttle position sensor. It is merely 2 switches in one. It tells the ecu when the throttle is closed and when wide open. If the ecu does not know the throttle is closed it will not signal the ISV to operate. Hence your ISV may be fine and its the potentiometer thats giving you the idling problem.

 

There are posts on this forum (including several of mine) showing how to test the potentiometer but if its an intermittent problem it may test OK but still cause problems. It costs silly money new (£120??) so usually you have to buy a used throttle complete with used potentiometer.

 

As I said in an earlier post, it is easy to replace everything in sight to try to solve a problem. I would therfore advise you to spend a few hours reading around the above issues. I find the forum search function does not work well for me and usually use Google which brings me back to the best posts on this forum.

 

I have also done other things with my 9A and found the biggest overall improvement to performance/mpg was gained by fitting a new Bosch Lambda sensor. I am not suggesting this is part of your current problem, only that its important for the overall wellbeing of this engine.

 

Edit: Having reread your most recent posts, ie the rich smell which you have always had, maybe your mixture has been altered before you got the car and needs sorting!

Edited March 25, 2013 by bmwcompact

[sam2.0 10]

The breakthrough appeared to be that the marking on the rocker cover wasn't true to the marks on the cams. I had lined up the cams, them placed the rocker cover on, then done the timing to the mark on the rocker cover.

 

After my *insert high number here* attempt, I decided to stripe it all back and start again. Turns when the mark on the rocker cover lined up with the cam pulley, the cams were out. I've put this down to over tightening on the rocker cover, therefore moving the position of the mark. The dizzy is also on the original mark it was before I started all this work, so I'm confident the timing is back to what it was. I've used my timing light to get it back to 6degrees BTDC (well, actually 2 teeth on the flywheel, as I didn't get an adjustable timing light)

 

I plan on cleaning this ISV as well as the throttle body over the next few days, if not the cause of my issues, its something that should be done anyway, its probably got 140k's worth of crap in them!

 

I'll do some more reading on how to test both of them and do that after I've cleaned the bits up.

 

To expand on my issues now:

 

High idle. Usually around 1300rpm

When changing gear the revs stay at what they were before pressing the clutch in, once engaging the next gear, the revs go to where they should be

The car will pull its self along in lower gears. If I get up to about 30mph and chuck it in 3rd or 4th, the car won't slow, it'll keep a constant speed, as if I'm applying a little throttle

Sometimes when coming to a stop, the revs will sit higher, roughly 2500rpm, until I depress the clutch and pull off.

[bmwcompact 10]

''The breakthrough appeared to be that the marking on the rocker cover wasn't true to the marks on the cams. I had lined up the cams, them placed the rocker cover on, then done the timing to the mark on the rocker cover.''

 

The valve timing/cambelt fitting is done before you fit the rocker cover.

 

The timing mark on the rear side of the cam pulley is supposed to align with the top of the cylinder head without the cam cover fitted. What do you mean by 'marks on rocker cover'?

 

If you have fitted the belt aligning to some mark on the rocker cover you've put it on wrong and are probably at least a tooth out.

[Supercharged 2]

Mate - it could be other things but sounds like the ignition timing is still not setup...

 

Whereabouts in the country are you? I it was me i'd try and acquire a pair of KR cams and get yourself over to Stealth to fit / setup on the rollers

[sam2.0 10]

Not the best shot, but this mark: http://imageshack.us/a/img534/4416/img5036o.jpg

 

So I lined up the cams, then put the cover back on, then fitted the belt etc. It was wrong, so when I re done it, I didn't take the rocker cover off again, just used the mark in the image.

 

Supercharged: You think its still a tooth out? The marking ALL line up now, even the cam markings. Oxford.

Edited March 25, 2013 by sam2.0

[bmwcompact 10]

Ah! I dont know about that mark (as they say a picture says a thousand words). I have only ever used the mark on the back of the cam pulley/top of the cylinder head-that works for every VW watercooled engine Ive ever worked on. In theory the mark you show should be right otherwise VW wouldnt have put them there. I don't even know if my 9A cam pulley had a mark on its front face.

[sam2.0 10]

As the cam pulley has a woodruff key, you'd expect them to line up, well they do, but the mark you aline the cam pulley to is on the rocker cover, which is a variable, depending on how tight the valve cover is! That was my mistake.

 

Just cleaned the ISV and its still got a high idle, in fact upon a warm start it now needs 3k revs to get it going! I've made it worse! I'll leave it to evaporate over night and try tomorrow.

[davidwort 0]

The engine mechanical timing is set up with the cam cover off, so you can see the cam to cam marks align, then of course the mark on the back of the cambelt pulley can only align with the head surface as the cover is off.

the outer mark should indeed line up with the V on the cam cover as in your pic.

It's a shame you didn't take pics of all the marks earlier as I asked though :)

you must have a proper quality lambda to get a 9a to idle hot properly, but it does sound like your ISV is dodgy

[sam2.0 10]

The marks on the fly wheel (both of them) and the cam markings all lineup, so I'm not sure why it'd make a difference. They cannot be unaligned unless the cams are fitted incorrectly. My fall down was using the rocker cover marker as its a variable.

 

Is the lambada sensor thing a joke? I don't understand.

[bmwcompact 10]

No joke! The lambda sensor is fitted to the cat and tells the ecu whether the mixture is correct. This then controls the fuel input via the meter head. If its defective or a cheap universal has been fitted it can lead to issues: as I said my car improved greatly when I fitted a new Bosch lambda sensor.

[sam2.0 10]

My last comment was directed at DavidWort, "you must have a proper quality lambda to get a 9a to idle hot properly", sounds sarcastic!

 

So, cleaning the ISV doesn't seem to have made a difference, still with the high idle and the rev staying up between gear changes. Suppose it could be knackered. I'll look for a new/used one.

[sam2.0 10]

Bump.

[sam2.0 10]

I've just checked the resistance across the throttle body connector and all seems ok. I've also sprayed wd40 on the air pipes and nothing changes, so no air leaks.

 

Still idling at 1500rpm and when you raise the revs and let them go, they go down slowly. I've also unplugged the ISV and it then idles correctly, but try and rev it and it bogs down.

 

What's next to try?

 

ETA: I've just checked the resistance over the ISV and it was about 900, but the car was slightly warm, it also moved (went down) as it was getting warmer, so that seems to be ok too.

Edited April 8, 2013 by sam2.0

[vw rule 19]

Hello mate,

 

I know the Throttle position switch and Idle Control Valve do communicate between one another,

so have you checked that you've got power and an earth to both.

 

I know on here somewhere there's an old thread where the guy had a similar problem as you regarding the idle,

on his it turned out to be an earth fault with in the ECU ( control unit ) it was coursing his car to idle at 1500 to 2000 RPM.

 

You say that you disconnected the Idle Control Valve plug and the engine was then idling correct,

so it 100% does sound like a ICV problem, so it must be a faulty valve or a wiring fault issue somewhere ?

 

Si

[Supercharged 2]

Was the car running ok before you messed around with the timing?

 

If so, get it to a garage like Stealth for a setup before changing any more parts, if the ignition timing is off then idle will be affected

[sam2.0 10]

Hello mate,

 

I know the Throttle position switch and Idle Control Valve do communicate between one another,

so have you checked that you've got power and an earth to both.

 

I know on here somewhere there's an old thread where the guy had a similar problem as you regarding the idle,

on his it turned out to be an earth fault with in the ECU ( control unit ) it was coursing his car to idle at 1500 to 2000 RPM.

 

You say that you disconnected the Idle Control Valve plug and the engine was then idling correct,

so it 100% does sound like a ICV problem, so it must be a faulty valve or a wiring fault issue somewhere ?

 

Si

 

Whats the best way to test for earth? With the ICV, TPS and ECU?

 

I've read before, that if you disconnect the ICV and the revs change, it means it works, as the ECU will go to a default setting. But, stuff I've read has been wrong before!

 

Was the car running ok before you messed around with the timing?

 

If so, get it to a garage like Stealth for a setup before changing any more parts, if the ignition timing is off then idle will be affected

 

Yea, I've said this before. Before I started the head gasket work the car was fine and pulled well, the only issue I had was water in the cylinder bore when cold (cracked HG)

 

I've also done the timing my self, with the movement of the dizzy, the lowest I can get it to idle is 1500rpm, to advanced and it idles higher, too retarded and it'll stay at 1500rpm.

 

I'm beginning to wonder if the belt if off a tooth, still.

[Supercharged 2]

Yes - I think the timing is out - just get it to a decent garage / VW dealer or specialist and get it checked / setup

 

Stealth or DG autotech are the best places I can think of

[sam2.0 10]

I'm trying to avoid that, a local VW specialist was £70+ VAT an hour just to look at it. If I had the money, I'd have got it sorted by a garage to begin with!

 

Doesn't help that some $^&* has nicked my timing light at work.

[sam2.0 10]

Re-timed it tonight, idle is as it should be. Going to get a garage to time it 100% with a advanced timing light.

 

Is that light at the end of the tunnel?!

[vw rule 19]

Oh yeah you're almost there now by the sounds of it, nice one :D

[sam2.0 10]

Not so fast!

 

Still idles high (only sometimes now) but doesn't pull well until 2500rpm. I've booked it into the garage to get timed up, I give up :(

 

This is how its timed up currently, also bare in mind I've not put a timing light across it yet (garage will do this)

 

The flywheel is bang on the line, but the cam pulley and cams are slightly off. If I move the cam to be correct, the slack in the belt between the cam and the intermediate pulley is far too much. I could then rotate the intermediate pulley, and put the slack between the intermediate pulley and crank, but still too loose.

 

ETA: Confirming from a mate, crank to be 100% TDC and then allow the cam to be slightly off is the way to do it, thats what the dizzy is for. Explained him. So, thats what I've done.

Edited April 16, 2013 by sam2.0

[sam2.0 10]

Update!

 

It was at the garage today for them to time it all. They said it was 1 tooth out, which is what I had it on before my last attempt. But they used an advance timing light to get that right.

 

The high idle isn't to do with the timing, but probably the ISV.

[vw rule 19]

When ever I replace the cam belt I always count the belt teeth,

you should be able to adjust out the belt slack via the tensionor,

but in the past I've had new cam belts with extra teeth which haven't quite fitted correctly,

which can course the valve timing to be out by a tooth or two.

 

With the old type distributor, on the older cars fitted with the points and condenser you were always able to fit a test light,

then you would turn i.e rotate the distributor until the test light came on,

as soon as the light came on then you were able to start the car and set the ignition timing.

 

With the later type distributor, fitted with the hall sensor you could rotate the distributor until you were able to hear the difference,

in the engine note i.e the engine RPM would slow down or speed up so you could rotate until you hear the RPM roughly half way set,

then drive the car down the road until you hear the engine pinking,

once you hear the pinking you would then rotate the distributor in the direction of retarding,

until the pinking has just gone, and this should be almost bang on set to the correct setting.

But this is only when you don't have the correct timing light / timing gun.

 

You should really check and set the ignition timing with the timing gun as Supercharged said earlier in this thread.

 

 

 

Good to hear Sam that you've got the valve timing checked and had the ignition timing checked / adjusted.

You can still purchase the idle control valve from VW main dealers, I've got the part number some where if you need it.

Or there are some slightly cheaper ones on Ebay I believe.

 

Si :thumbleft:

[sam2.0 10]

Thanks Si. I've got someone who's selling a use ISV, I'll test that first before spending dealership money!

 

Now it's sorted, it'll be up for sale, as I'm moving back to an E30, the corrado has been great fun, but I miss the E30s so much, this will be number 4.