Starting Problems

[samauty 0]

Hi there, I have a 1.6 89 205 GTI, and it will not start when warm or when its been used in the same day. Once it is running, its great, loads of power, but quite a high tickover of 1500 rpm? If i leave it overnight (too cool) it will start first crank instantly. I thought it could be the ignition module? Where should i start?

[DjB 0]

It could any number of things...but,

 

I had a similar problem to this in a Galant VR4 I had and it turned out to be that the starter motor solenoid was jamming up. It tended to happen more so on hot days. The high idle is strange though. Does it still idle at 1500 once its warmed up? Iys clearly going to idle high when its cold but if it idles high once its at operating temperature all you need to do is your adjust idle. I'm fairly sure if you searched idle adjust in this forum you would find the answer.

 

As for your 205 not starting, start with basics and start eliminating all possibilities... Use the search function too.. It will save you having to wait for people to respond.....

 

Good luck...!!

 

Chris

[samauty 0]

Ok i think I may have found the problem

 

Spoke to a very helpful chap at autofive and he said there is a good chance it is the SAD.

 

Here's what i did: I started the car from cold, took it for a drive and warmed it upto working temp. Once back home i kept the engine running and clamped one of the hoses running to it. This dropped the revs and the engine idle was about 1000rpm; therefore it must be stuck open?

 

Is this likely to cause my hot starting problems too, as the mixture is too rich?

 

Getting to this thing looks a bit of a bitch. Are these things fixable, or is just best getting another?

 

Sam

[DjB 0]

SAD...

 

I'm not sure I know what that is. What is SAD an abbreviation of? But it certainly sounds like the bloke you spoke too is on the money.

 

 

 

Chris

[jord294 95]

SAD = supplementry air device

 

similar to a choke, when starting the car from cold.

[DjB 0]

Where does it get its air from and where in the engine is does it sit...

 

Chris

[samauty 0]

I think it takes air from the pipe running from the AFM to the throttle body and then carries it to the SAD unit which is right below the dizzy. It then has another pipe running out which runs to the inlet manifold.

Correct me anyone if i am wrong, but at cold startup it opens to allow more air to enter through the AFM (air flow meter) which in turn tells the ecu that more air = more fuel; hence a richer mixture. Once the engine is warm it closes and shuts, thefore stops more air entering and stops more fuel entering.

My problem is that mine is stuck open, so the engine is running a rich mixture all the time.

 

Sam

[DjB 0]

Install a manual choke...... Hahahahahahahahahaha

 

Just kidding. That makes sense. I'm without a 205 at moment so I was having trouble picturing the part you were talking about. Thanks for clearing at all up though. Its an odd design though. Effective but at the same time odd. I would've thought that an easier method would have been the ECU reading the oil and water temp and see that motor isn't up to operating temp and would inject more air and fuel.

 

I'm still learning about 205 ECUs so the above rant probably isn't even possible... LOL

 

 

Chris..

[gti-si 0]

Correct me anyone if i am wrong, but at cold startup it opens to allow more air to enter through the AFM (air flow meter) which in turn tells the ecu that more air = more fuel; hence a richer mixture. Once the engine is warm it closes and shuts, thefore stops more air entering and stops more fuel entering.

 

The SAD allows unmetered air in AFTER the AFM. Extra fuel is controlled by the ECU water temp sender. In the SAD there is a bimettalic strip and a small heater coil powered by the ECU, as the strip bends (effect of heating) it rotates the disc around to a closed position. I can only describe that disc as what you'd find on top of a parmesan container. All this info can be easily found on the main site anyway. To solve it just whack the SAD off and give it a clean with some carb cleaner or petrol. It could well just be clogged. Failing that just stick a wanted add up, they'll be plenty about!

 

Chris, thats pretty much what the ECU does anyway, it controls fuel by sensors and "injects" as you would put it, air into the inlet manifold

Edited January 5, 2008 by gti-si

[welshpug 1,678]

the air isnt un-metered, it simply bypasses the throttle butterfly from the intake pipe AFTER the Air flow meter.

 

apart from that little bit you are entirely correct.

[gti-si 0]

Ahh, yeah your right, it all comes from the AFM in the first place. *Slaps wrist* haha

[samauty 0]

cheers everyone for your help! Ill have a look at this SAD when my exams are over and i ve no more revision to do!

However I do have another problem....lol

 

I have recently rebuilt the engine (1.6) and compared to a 1.4 polo i used to drive it is more powerful and much much more fun to drive - especially the country lanes near me at night.....

 

Everything pretty much has been done on the engine in the way of consumable parts; bearings, piston rings, valve stems, gaskets etc, and whilst doing all the work myself I have learnt so much.

 

Like i say the engine runs great, but once it is warm and the oil temp has risen it does have a tappety noise, like the type of noise that tells you it needs the tappets adjusting. - (but this engine has no tappets)

 

Now i am aware that these are not the most refined beasts in the world, but I cant help but think something needs doing?

 

I am i right in thinking that there are no sort of valve related adjustments. I wondered if it could be the oil spray bar which provides oil to the cam is maybe blocked or something, as when the engine is cold (thicker oil) it doesnt tap. I am running mid range semi-syn oil 10w40. I ve also only done prob 500 miles since the engine rebuild - maybe not even that.

Sam

[simonb 0]

Probably valve clearance - It's adjusted by fitting different size shims under the camshaft buckets. You have to measure when cold and order the correct size shims - not the easiest of jobs and the 8v engine is a tappety anyway. Suppose you could try using 15/40w oil instead, but probably easier to live with it IMHO.

 

PS. Just thought - have you checked the gear oil? could just be a noisy box as the level is getting low - Mine was quite noisy until I replaced a driveshaft at the weekend and topped it up - is quiet again now.

Edited January 6, 2008 by simonb

[samauty 0]

Cheers mate, ill check that also. I did refill it when i put the driveshafts back in, but ill double check the level to be sure

Another quick question also. One of my driveshafts has gone, as when i bring the power in on a right hand bend its the typical knocking noise. Which driveshaft does this mean is knackered? the longer drivers one or the shorter?

[djinuk 2]

i also found my 205 noisy, have just done the head gasket,

[DamirGTI 345]

cheers everyone for your help! Ill have a look at this SAD when my exams are over and i ve no more revision to do!

However I do have another problem....lol

 

I have recently rebuilt the engine (1.6) and compared to a 1.4 polo i used to drive it is more powerful and much much more fun to drive - especially the country lanes near me at night.....

 

Everything pretty much has been done on the engine in the way of consumable parts; bearings, piston rings, valve stems, gaskets etc, and whilst doing all the work myself I have learnt so much.

 

Like i say the engine runs great, but once it is warm and the oil temp has risen it does have a tappety noise, like the type of noise that tells you it needs the tappets adjusting. - (but this engine has no tappets)

 

Now i am aware that these are not the most refined beasts in the world, but I cant help but think something needs doing?

 

I am i right in thinking that there are no sort of valve related adjustments. I wondered if it could be the oil spray bar which provides oil to the cam is maybe blocked or something, as when the engine is cold (thicker oil) it doesnt tap. I am running mid range semi-syn oil 10w40. I ve also only done prob 500 miles since the engine rebuild - maybe not even that.

Sam

 

Hi !

 

It could be the exhaust manifold also , as cracked exh. manifold (or blowing out from the exh. manifold gaskets – check for a gas tight seal in between the head and the exh. manifold .... or blowing out from the exh. downpipe mesh ring ..) sounds very similar , tappet sound just like a bad valve clearance adjustment ...

 

Cheers !

Damir

Edited January 7, 2008 by DamirGTI

[samauty 0]

Ok fitted new SAD today and it has sorted the tickover when the engine is hot and cold

 

However it still is difficult to start when its hot. Its fine if you start it immediatly when the engine is hot and its been running. But, leave it 15 minutes and you have to crank it loads.....

Iam thinking maybe a new ecu temp sender?

Edited January 10, 2008 by samauty

[paulcoxon 0]

Did you ever figure out the hot starting issue I've got the same problem

[samauty 0]

well i have been trying to today!

ok first of all i replaced the SAD, which has now sorted the cold idle and the idle is now good when it warms up - ie around 1000rpm.

the other day i was driving the car and it started to misfire really badly, i was down to say 2 cylinders and everytime i touched the throttle it started to die. luckly i was about 1/2 a mile from my house so with a tiny bit of throttle and some coasting i made it

I figured it had to be ignition related as the car seemed as though it was getting fuel. Today i have replaced the coil and ignition amp and on a 20 min drive today there were no misfires, but it did kangeroo once

so hopefully ive sorted it.

It also seemed to start better after about 10 mins of leaving when hot, but i tried it about an hour later and it was still the same!

so again i back to square friggin one!!!!!!!!!!!!!!

 

the misfire was very weird as it misfired really badly and then all of a suddern the engine would run perfect.

 

any suggestions anyone?

sam

[CosKev 16]

Have you checked the ignition timing?

 

What does it do when it won't start,trying to fire or not firing at all?

[samauty 0]

it wont start first turn of the key. no firing nothing. doesnt even splutter. but if i keep cranking it over - for 3 or 4 turns of the key it eventually will.

[DamirGTI 345]

Ignition amplifier maybe (I've had that this winter - every morning 4-5 cranking until the engine eventually fired up , then i change the amp. for a spare one and bob's your uncle - try ..)

 

Cheers !

Damir

[samauty 0]

changed the amp and coil and still difficult when hot.

 

What does the techmetric reley do? i ve heard these can be troublesome.

 

I must admit though since i have changed the amp/coil it does start much easier from cold. but still difficult from hot. however my tappets do need adjusting so this could be related too?

[CosKev 16]

. but still difficult from hot. however my tappets do need adjusting so this could be related too?

 

Think tappets would only effect it if they were over adjusted,ie not letting the valves close fully and thus losing compression.