Idling Problems (but Not On Warm Dry Days) !

[Phil205 1 1 Cars]

Hi,

 

Can anyone help me to diagnose the idling problem with my car. It would be much appreciated :-

 

Peugeot 205 GTI 1.6

UK - E Reg 1988

Engine Type - XU5JA - 115 PS (113 hp/84 kW)

Bosch Multipoint Injection Jetronic (LE2 or LU2 ?)

Chassis Number - available if of use ?

 

Problem (in Winter or cold/wet day) :-

 

· When the car is started, it runs ok for a few minutes. The engine revs are steady.

· Once the car has been running been for 20 to 30 minutes, it runs ok. The engine revs are steady.

· The problem is that whilst the engine is warming up, and the car is stationary, e.g. at traffic lights, the engine revs go up and down significantly. Often the revs will drop so low that the engine will cut-out. I tend to have to keep my foot on the accelerator a little to keep the revs up.

· I adjusted the idle speed adjustment to give more revs. This helps, but doesnt stop the problem.

· Engine revs drop, and stay lower, when the lights and/or heated rear windscreen are switched on.

· I noticed that there is a build up of creamy gunk at the oil filler cap. This has the consistency of double cream and has been getting into the two breather pipes that leave the top of the oil filler cap. I have cleaned this out several times. Cleaning this out seems to help the problem a little, for just a few days.

 

Summer (dry/warm day) :-

 

· The problem hardly occurs when the ambient air temperature is warmer.

 

 

Possible cause ? :-

 

· Air Flow Meter (AFM) ?

· Air leak ?

· Temperature sensor ?

· Oil filler cap is loose. A bolt may be missing ?

· The Supplementary Air Device (SAD) does appear to be open, at least when the engine is fully cold, though it might be closing prematurely, i.e. before the engine has warmed up ? Squeezing the air pipe by hand, lowers the revs, as expected, when the engine is fully cold.

· It has been suggested that blocking the thin breather pipe between the oil filler cap and throttle, then readjusting the engine idle speed adjustment screw, may fix the problem ?

· I understand that the gunk could be an indication of a possible problem with the cylinder head gasket, but is more likely to be just a normal feature of (old) 205 GTis, particularly one that is used in stop/start city traffic ?

 

Questions :-

 

· Why is it a problem in cold weather, but not so much in warmer weather ?

· Why do the engine revs go up and down significantly to the extent that the engine will cut-out ?

· What can be done to fix this problem ?

 

Thanks,

 

Phil

[Grim.Badger 15]

Mayonaise as it is usually called isn't much to worry about as long as it's only forming on cold days.

 

On cold days water seems to work its way into electrial joins, the most problematic being the earths. Check the main earth strap on the gearbox and any others for corrosion as this would explain your idle problems as well as the engine struggling to run the ancilleries (although this could also be a dying battery or alternator).

 

I checked up on revs going up and down as mine does it periodically and iirc it's likely to be a fault with the ignition amp, or the earth wire from it.

 

An air leak would probably be more liekly to cause problems on a cold idle, but it is worth checking that there are no empty bolt holes on the side of the inlet manifold as these are infamous for letting in huge amounts of air.

[M_R_205 5 1 Cars]

i see this is you first post so welcome

 

Firstly 205`s never idle well it could take forever to find the problem the most common causes are in the list you mentioned, afm SAD and ecu temp sensor, id say fit a new or known good sad first as thats the most common culprit, then if that fails to sort it try a known good afm

 

 

or if you have a bit of extra cash floating around, throw away the std injection and fit something fancy like carbs or TB`s

Edited July 11, 2007 by M_R_205

[Rob_the_Sparky 9]

My guess is SAD. I have a similar problem with my 309 but not so bad that I've got round to fixing it.

 

The SAD closure has almost nothing to do with engine temperature, it is closed basically by a timer, with some influence from engine temp. Heat closes it (via a bi-metallic strip) but most of this heat comes from a heater turned on when the engine is started. The starting temperature and engine temp will have an impact but not that much. The SAD will not close with the heater disconnected.

 

As such the SAD is a pretty crude device so it isn't surprising if it either closes early or late...

 

Rob

[brianthemagical 1]

My guess is SAD. I have a similar problem with my 309 but not so bad that I've got round to fixing it.

 

The SAD closure has almost nothing to do with engine temperature, it is closed basically by a timer, with some influence from engine temp. Heat closes it (via a bi-metallic strip) but most of this heat comes from a heater turned on when the engine is started. The starting temperature and engine temp will have an impact but not that much. The SAD will not close with the heater disconnected.

 

As such the SAD is a pretty crude device so it isn't surprising if it either closes early or late...

 

Rob

 

so would you recommend opening or closing the sad slightly? thanks.

 

and for referance and search use

 

link

[Rob_the_Sparky 9]

so would you recommend opening or closing the sad slightly? thanks.

 

Unknown TBH as I don't know what causes it to close too early. At a guess if you can open it up more then it will take longer to close but I've not had one apart to fiddle with so it is just an educated guess. Not even sure they can be adjusted...

 

Rob

[Phil205 1 1 Cars]

Unknown TBH as I don't know what causes it to close too early. At a guess if you can open it up more then it will take longer to close but I've not had one apart to fiddle with so it is just an educated guess. Not even sure they can be adjusted...

 

Rob

 

Rob,

 

Thanks for your help. There is information on the SAD on http://www.205gtidrivers.com/ . I tested the SAD using Method 1. I will try Method 2 !

 

Thanks,

 

Phil

[C_W 3 1 Cars]

IME it's usually the idle mixture (too rich). When the engine is warm and fluctuating, try unscrewing the allen key on the AFM out and see if it changes anything.

[Rob_the_Sparky 9]

IME it's usually the idle mixture (too rich). When the engine is warm and fluctuating, try unscrewing the allen key on the AFM out and see if it changes anything.

 

I'd agree for a warm engine but my 309 is perfect when warm (well as good as it gets for Jetronic) and fine when stone cold but about 600rpm for a few minutes inbetween. Idle is good even at 600rpm but if you let the revs drop too fast then it will stall.

 

I'm assuming that this is the same problem that Phil is having from what he describes.

[Rob_the_Sparky 9]

Rob,

 

Thanks for your help. There is information on the SAD on http://www.205gtidrivers.com/ . I tested the SAD using Method 1. I will try Method 2 !

 

Thanks,

 

Phil

 

To confirm it is the SAD try Method 1 when cold and again when part warm, e.g. when the idle has dropped. My expectation is that revs will drop when cold but not when part warm showing that the SAD has closed early.

 

Rob

[feb 47]

I have had this problem for long time, in the end i have learnt to keep both the accelerator and brake pressed when stopping at junctions. Fluctuations happen only when the engine is cold until it has warmed up. let us know how you get on as I haven't got round to do anything about this.

[Phil205 1 1 Cars]

IME it's usually the idle mixture (too rich). When the engine is warm and fluctuating, try unscrewing the allen key on the AFM out and see if it changes anything.

 

Thanks for your help. I'll give this a go.

 

Should I mark the screw before adjustment so that I can put it back afterwards if no improvement ?

 

Does unscrewing make the fuel less rich, by adjusting the amount of air in the mix ? How much do I turn the Allen key. ?

 

Thanks,

 

Phil.

[Rob_the_Sparky 9]

Yep, unscrewing opens up the air bypass (allows more air past the flap in the AFM) leaning out the idle mixture. It is a fairly coarse adjustment but watch for the screw running off the end of the thread, this is also quite common and clearly it will not adjust any furhter than this point.