Lumpy idle when cold......

[rayaans]

Some shuddering is normal and will occur on all modern cars on a cold start 

Its to do with trying to warm the catalytic converter up as fast as possible. 

Happens on the RX, IS and VW Golf

[Verbout]

Here goes:

I’ve dosed my tank a couple of times now with injection cleaner.

I have cleaned the MAF, throttle body and checked the PSV or whatever it is, it rattles.

I’ve check all pipe work and found no chafing or splits.

I have unplugged everything in the area adjacent to the intake system and either sprayed it with contact cleaner or WD40.

And finally I’ve stopped letting my petrol gauge light tell me when to fill up.

I don’t know whether my last efforts the other day of checking the connections was what sorted the issue, but it’s back to it’s lovely self.  

Either that or the threat of being part exchanged has sorted it.

PS, It never set any codes.

[Beamish]

Good to hear you got it sorted.

Enjoy!

[Verbout]

2 hours ago, Beamish said:

Good to hear you got it sorted.

Enjoy!

Thanks, wish I’d been able to pinpoint what the issue was though.

[peachy]

5 hours ago, Verbout said:

Thanks, wish I’d been able to pinpoint what the issue was though.

My guess was a dirty MAF. I've had a similar issue on a variety of motors over the years and a good clean of the MAF usually does the trick.

A regular dose of injector cleaner is always a good idea but I recommend using super unleaded all the time to keep the system clean. 

Trouble with the IS250 is that people just tend to potter about in it and not letting the revs get up high enough to blast any rubbish out.

My wife drives the 250 about like a granny and I've recently noticed its been a tad sluggish and below par.

Just last week I gave it a bit of an Italian tune up. I put it into select/sport and drove for 20 mins down the motorway in 3rd gear at around 5500 rpm.

For the first few minutes it started chucking out a lot of muck but soon cleared up.

Anyway the car feels much much better now and noticeably more responsive. 

[Verbout]

We’ll never know.   :)

My search for the cure wasn’t scientific, I just tried different remedies on different days.

The only thing that brought an immediate solution was the cleaning of several connections in and around the air intake.

[Verbout]

Sorted......

I have cleaned and sprayed all the induction components with cleaners, there isn't a cleaner induction system in the county.

I bit the bullet and took off the throttle body, first disconnected the Battery and left it for an hour, I believe you have to let the capacitors lose there charge.

The throttle body was sprayed and left to soak for several hours and basted every 30 minutes with the cleaning fluid.

It was put back together, Battery connected and turned on the ignition. I waited for all the clinking and clunking of the electronics to finish and the car started with a cough, I left it to idle for five minutes and then took it for a drive.

A lot better................... the solvent in my plastic container was dirty and there was a lot of grit in the bottom.

I may consider taking it off again in the summer and leaving it soaking for longer.