starts up better when it has been sitting all night, floating idle...same thing?

[1.8tguy94]

So when I start my car up from siting over night, it starts with about 1.5 cranks. When I have been running/driving it, it starts up with 3.5 cranks or so. Not a huge difference but something I of course would notice. I also noticed when its been running a while, the idle floats a bit, sometimes you can feel it but not often. Could this all be connected into the same thing? I've been wondering about this for a while now!

[Rockerchick]

What car?

[1.8tguy94]

2005 Jetta tdi mkiv

[Glegor]

So when I start my car up from siting over night, it starts with about 1.5 cranks. When I have been running/driving it, it starts up with 3.5 cranks or so. Not a huge difference but something I of course would notice. I also noticed when its been running a while, the idle floats a bit, sometimes you can feel it but not often. Could this all be connected into the same thing? I've been wondering about this for a while now!

any codes?

limp mode?

what is this "floating idle" you speak of?

describe it for us please?

[1.8tguy94]

There is absolutely nothing. No codes, lots of power, everything is perfect, minus this slight idle floating. Basically if you really stare at the needle you can see it moving up and down (barely, you really have to look at it, very small amount). It only does this when the car is warmed up. And it takes about 1.5 extra cranks to start up when its been running....the normal person would totally NOT notice this. But me being the picky and anal person, I notice EVERYTHING. Usually you cant even hear the engine sounding different, occasionally, but not usually! Im just trying to make sure its nothing majoy (camshafts or something :p)

[1.8tguy94]

I have decided its the lift pump, does anyone agree/disagree?

[MXTHOR3]

I have decided its the lift pump, does anyone agree/disagree?

Either that or the tandem.. But the liftpump is the easier (and cheapest) of the two to replace.

[1.8tguy94]

wouldnt there be like a huge issue if the tandem pump wasn't working right?

[MXTHOR3]

wouldnt there be like a huge issue if the tandem pump wasn't working right?

Nope.. If you've got a early LUK tandem pump (black cover) there's a spring inside that can break, but the car will still function for the most part.. But you'll get erratic idle, etc... Most guys replace it with the Bosch unit and are good to go.. I'm waiting for my LUK tandem to give up the ghost any day now..

I also doubt it's your liftpump that's the issue.. Could be a bad temp sensor that's pulling timing once the engine is warmed up..

[1.8tguy94]

I was also thinking the temp sensor could be it too....thats the ect sensor right? I might just replace that...its not too expensive. Mine I believe is just metal, no plastic that I can see, plus its an 05 so maybe its newer?

[MXTHOR3]

I was also thinking the temp sensor could be it too....thats the ect sensor right? I might just replace that...its not too expensive. Mine I believe is just metal, no plastic that I can see, plus its an 05 so maybe its newer?

My '05 BEW has the LUK tandem pump stock. It's right there on the drivers side of the engine, take a look

[1.8tguy94]

I know it's there lol, I will go check closer. so I should be looking for a black plastic piece on it?

[1.8tguy94]

Where is the FTS located on my car? I couldn't get a straight answer on google!

[1.8tguy94]

Anyone?