Lumpy Idle

[Mr Teflon 1 1 Cars]

Hi All.

 

Brought the car back after Easter with a very lumpy tickover and smell of fumes. Quick check of exhaust and breather systems revealed a pipe off the recirculation system.

 

Went over last weekend and again - same symptoms, but no visible pipes off the recirculation system. Now I know the old girl's done a very hard 1000 mile round trip but I'm a little kerfuzzled by what I suspect is something obvious!

 

Any ideas?

 

Cheers

[Jer309GTi 3]

Could be a split in one of the pipes, causing an air leak?

[Mr Teflon 1 1 Cars]

Hhmmm - went over the system last weekend - no leaks.

 

Checked the Idle control valve - working OK

No pipes off.

Checked the temp sensor for the ECU, K light on when disconnected, and wouldn't run, so wiring OK at least, but I suspect that as the car idles properly when cold and not when warm that this sensor has failed and the ECU is over fuelling the engine thinking its cold.

 

Reading the other threads about this with interest too

 

So - does anyone have a part number for this sensor - on a phase 1 1990 ?

 

Just got back from another trip to Germany last night - the car is running great (apart from an intermediate driveshaft bearing failure! - might order a Group N bottom mount as the opportunity to do both at the same time can't be passed up )

[danrogers 0]

mine does this v.bad, warm up is ok but slightly smelly but if the car is warm and i turn off then on again while its still hot its lumpy as anything?

[Mr Teflon 1 1 Cars]

Changed the sensor this morning - still got the problem.

 

Going to go through every breather/vacum pipe tomorrow with carb cleaner and compressed air to eliminate blockages. I'll clean out the idle valve too but I'm pretty sure that is working having had it off and checked it was doing something!!!

 

Keep you posted.

[Mr Teflon 1 1 Cars]

OK - I see others are experiencing similar problems.

 

I was pretty convinced there was a air leak somewhere, and traced it back to a perished injector seal and an inlet manifold gasket drawing copious amounts of air through at idle.

 

Got a set of injector seals for £3 from a VW dealer (same Bosch injectors as an 89 Golf GTi), changed the inlet manifold gasket and problem solved.

 

Running like a dream again.

[Jer309GTi 3]

OK - I see others are experiencing similar problems.

 

I was pretty convinced there was a air leak somewhere, and traced it back to a perished injector seal and an inlet manifold gasket drawing copious amounts of air through at idle.

 

Got a set of injector seals for £3 from a VW dealer (same Bosch injectors as an 89 Golf GTi), changed the inlet manifold gasket and problem solved.

 

Running like a dream again.

<{POST_SNAPBACK}>

 

Glad you got it sorted in the end

 

Got a set of injector seals for £3 from a VW dealer (same Bosch injectors as an 89 Golf GTi)

 

<{POST_SNAPBACK}>

 

Handy bit of info

[KRISKARRERA 2 1 Cars]

My old Mi16 used to run lumpy as hell at idle once it had warmed up. Discovered it was running too lean so I screwed in the thingy on the AFM to richen the mixture a bit.