Thorough Service

[james306 0]

My 1.9 lump is running a little rough, it hunts at idle and doesn't like running under 2Krpm while driving. She misses a bit under said revs.

 

My intention is to give her a thorough service, drain, flush and replace oil. Change gearbox oil. Replace plugs, oil and fuel filter. Also I intend to replace the Cambelt, water pump and pulleys shortly and obviously flush and refill coolant.

 

I'm hoping this will either cure the issue, or help me identify where the issue is. Someone else suggested it could be the AFM sensor.

 

Any other suggestions regarding service of engine to get her purring as she should be?

[omega 82]

service is always good but i dont think that will cure your proplem.

[shalmaneser 26]

Give the throttle body idle adjust screw a good clean if you haven't already. Also look into 're tracking' your AFM, do a search plenty of info about it on here.

 

Some carb cleaner directed down the SAD piping might be an idea, it can get a bit gunked up.

 

If it's misfiring under 2K then there may be an ignition problem, check the leads are in good nick. Also double check plug gaps. Obviously check air hoses for leaks while you're there.

 

However, as mentioned a decent service will do it no harm at all!

[MerlinGTI 3]

Service is a good base to diagnose further from. Without doing the service first and elimanating the service parts fixing your problems will be far trickier. Id focus your time and money on the engine only for now as it seems to have issues.

 

Oil + Filter

Plugs

Leads

Fuel Filter

etc..

 

Test the TPS (usually knackered),

Test the ECU temp sender

clean out the Throttle body big time. Adjust according to Haynes.

Injectors will probably be gummed up (mine were) worth getting them cleaned (see group buy section).

Clean the AFM with carb cleaner + Air but dont tamper with it just yet. Check to see if its been tampered with before.

Clean & test the SAD

 

Get it on a gas analiser set up for the correct CO on idle and go from there! All the testing is explained in haynes manual very well. Our cars are at the age now where pretty much all of these things will need attention if they havent been done recently. Still bits are pretty cheap, so crack on!

[JRL 14 1 Cars]

Good advice given here already.

1. someone also mentioned recently on here to clean the pins on the air flow metre plug as this can help with jerkiness or idling. I cleaned mine with a screw driver scratching the surface and im sure it did help.

2. I regularly clean the oil breather pipes as they are prone to getting mayo build up.

3. every 6 months I clean the throttle body out as mentioned already with carb cleaner I was talking to an old mechanic and he said back when they were a few years old a lot of people used to replace the the afm because it was causing probs but was in fact sooted up TB.

4. check the accleration cable. mine was once a bit too tight and caused probs.

 

other than this generally worn out TB, or afm are the usual suspects.

[james306 0]

Thanks for the suggestions so far, will try and get started today.

 

What does the 1.9 engine generally idle at?

Edited November 4, 2010 by james306

[johnhenry 20]

when i got mine back in the summer it has many similar issues to what your describing

to the engine, I have:

Replaced all filters,

Fluids

Advanced Vacuum

Collant Temp sensor (lil blue 1)

Bypassed the brown multiplug - loads of guides on here

HT leads

HG

played around with the idle control valve % AFM screw to get the CO2 mix correct

 

the hunting revs sounds like the coolant temp sensor tbh, but i found with alot of things, its a culmination of many small issues

Hope this helps

[chicargo 0]

Good advice given here already.

1. someone also mentioned recently on here to clean the pins on the air flow metre plug as this can help with jerkiness or idling. I cleaned mine with a screw driver scratching the surface and im sure it did help.

2. I regularly clean the oil breather pipes as they are prone to getting mayo build up.

3. every 6 months I clean the throttle body out as mentioned already with carb cleaner I was talking to an old mechanic and he said back when they were a few years old a lot of people used to replace the the afm because it was causing probs but was in fact sooted up TB.

4. check the accleration cable. mine was once a bit too tight and caused probs.

 

other than this generally worn out TB, or afm are the usual suspects.

 

 

hi i could be very wrong but when you say "2. I regularly clean the oil breather pipes as they are prone to getting mayo build up" how bad is the build up of mayo ??, have you checked to see if you have any mayo in the header tank if so then could it be the head gasget going ??. i do know i do get the tinyist bit of mayo in my breather pipe due to condensation but only a very very slight film of it once a year

[JRL 14 1 Cars]

hi i could be very wrong but when you say "2. I regularly clean the oil breather pipes as they are prone to getting mayo build up" how bad is the build up of mayo ??, have you checked to see if you have any mayo in the header tank if so then could it be the head gasget going ??. i do know i do get the tinyist bit of mayo in my breather pipe due to condensation but only a very very slight film of it once a year

 

I dont get it now im using it daily and I go the longer way to work as its only a short journey The head gasket is fine, it was rebuilt a few years back. Alot of people ask this question on this forum because there mechanic told them it may be a HG but its just the breather set up.

[chicargo 0]

I dont get it now im using it daily and I go the longer way to work as its only a short journey The head gasket is fine, it was rebuilt a few years back. Alot of people ask this question on this forum because there mechanic told them it may be a HG but its just the breather set up.

 

 

hi there, like i said "i could be very wrong" and im sure short journeys could be the cause of a bit of mayo build up in the rocker cover on normal cars, or in the case of the 205 gti's in the breather pipe/ oil filler cap. but form my own experiance if the build up is exsesive and would need cleaning out every six months of so, and was accompanied by mayo in the header tank it would suggest the head gasget.

all the best, chicargo

[james306 0]

Right! I finally got round to having a proper look into the rough running, I blasted some carb cleaner into the AFM sensor housing to see if it would help and save me having to open it up, then put some cleaner into the throttle body. She is now smooth as anything under 2krpm

 

As for the misfire, the AFM sensor bracket appears to have been bent down (probably someone leaning on it while working on the engine) and has been rubbing on the HT leads, as a consiqueince it has eaten the coating from number 1 and 4 lead. Couldn't see/hear it arcing as the housing was touching it, but once I moved it away to clean it up, saw the arcing and could actually hear it from the back of the car. It times perfectly with the misfire!

 

New set of HT leads will be going on this weekend, bracket will be bent back to where it should be.

 

Also going to have a major flush of the cooling system as i'm getting no hot air through, with any luck it will just be a gunked up heat exchanger as I have tried to bleed it and still no luck. I will also know that I have plenty of anti-freeze in there too.

 

Oil and filter next on the list, may get done this weekend, if not asap.

[JRL 14 1 Cars]

good to know you got it sorted you really cant beat a good service and clean can you.

[james306 0]

She is much happier for it, however she still idles a little high. She will idle at around 1100 once warmed up, and occasionally higher.

 

Do the 1.9 engines have an automatic choke? I'm thinking it could be that sticking on? I haven't really had time to investigate this recently and it's too bloody cold to be working on cars outside!

[JRL 14 1 Cars]

1100 isnt bad for a 205 gti ideally it would be 900 but even a peugeot mechanic told me he has never known one to idle well. I personally settle for anything 1200 or less. you can try adjusting the idle screw on the throttle body a little more.

[welshpug 1,666]

Idle should be around 850-900 when warm with a standard engine.

 

There is no choke, just an SAD (Supplementary Air Device) which is just a vary basic valve operated by a bimetallic spring, said spring is heated by a 12v+ supply from ignition as well as heat from the thermostat housing which its bolted to.

 

As long as throttle initial position is set correctly, then just wind the air bypass screw in on the throttle body, be sure to get the CO at idle checked, I found it to affect idle quality dramatically.

[mhyphenl 10 1 Cars]

Idle should be around 850-900 when warm with a standard engine.

 

There is no choke, just an SAD (Supplementary Air Device) which is just a vary basic valve operated by a bimetallic spring, said spring is heated by a 12v+ supply from ignition as well as heat from the thermostat housing which its bolted to.

 

As long as throttle initial position is set correctly, then just wind the air bypass screw in on the throttle body, be sure to get the CO at idle checked, I found it to affect idle quality dramatically.

 

Normally if the idle won't settle below 1100 its the throttle position switch, either incorrectly set or broken! It makes the engine think you still have your foot stightly on the gas and so supplies a bit more fuel. That was the problem on mine. A quick adjustment so it clicked at rest and it was idleing at 900 no problem. The other problem could be an air leak but that would make it run richer!

[james306 0]

Cheers for the suggestions, I shall check for an air leak later. Failing that have a look at the TPS.