skene

Apparently I've been running around with it unattached for some time.
Could that have something to do with my not being able to pass emissions too?

skene

bump for any ideas?

spazegun2213

could be, It looks to be a hose heading to a temp valve... reconnect it and see.

Yabo

any vacuum line disconnected is going to cause running problems...

Chupa

Emissions - almost certainly. I could dig up a better picture to be sure, but it looks like you've had a disconnected vacuum line. Several components throughout the engine bay use the vacuum created by the intake manifold to power the devices. A loss of vacuum can affect all of the devices along that service line. And like the failure of a O2 sensor, the system will likely default to a fully rich, though functional condition.

skene

Yeah, sorry about the bad pic. It was on my computer and I didn't feel like searching for another one. Besides, this one tells you what everything is

If I'm reading things right, that should only affect things when the car is warmed up right?

cjeckert

no a brech in any line can effect the vacume pressure in the entire vacume system

gregeast

That line connects the temperature valve (aka thermovalve), which is part of the fuel vapor purge system, to the shutoff valve which in turn is connected to the gas tank. The line on the other side of the temperature valve connects to that vacuum port underneath the throttle body because the fuel vapor is only supposed to purge when the throttle is open (ie. not at idle) and when the engine is warm (ie. thermovalve is open). There is a small hole in the throttle body, right behind the throttle plate that creates a vacuum when the throttle plate opens by virtue of the venturi effect that's caused by the incoming air passing over the hole.

Obviously, if the line is off you have a vacuum leak, which could contribute to the car running a little lean at idle once the car is warm (temperature valve is closed when cold), although that port is very small in the throttle body so it'd be a small leak and while it won't help your emissions it's unlikely that it would cause a major problem either.

With that line disconnected you are basically not purging fuel vapor. That means the car is likely hard to start after you shut it off when it's warm. Some remove the whole vapor purge system and seem to get along fine. I'd suggest just hooking up the vacuum line again!

Probably more than you wanted to know...

genikz

What were your emmissions numbers by the way? Running lean is generally shows up as low HC's and high NOx's. This was the case when I had a vacuum leak. I replaced all the lines with the Lindsey Racing silicone vacuum hose kit, which fixed the lean problem and lowered my NOx's. No need to replace your lines if 'they aint broke' though...

skene

gregeast, that's actually the kind of information I was looking for. It never hurts to know more about how this thing works.

I've got the lindsey vacuum hoses on there already, but that one had popped off without my knowing at some point. I have also had an intermittent warm starting issue that I've been slowly replacing parts for to fix. I'm wondering if that line was the problem I was missing the whole time. Well, that and the bad FPR on there.

My emission numbers were around half the limit on everything except CO%. It was at .5 when the limit is .44 at 15mph and at the limit of .64 at 25mph. I'm going to get it tested again shortly anyways, so we'll see what happens there.

Thanks for the help guys!

gregeast

I'm pretty sure you just solved your warm start issue at least and hopefully the emissions issue as well.

Glad I could help. Only reason I know so much about this little sub-system is that I had to remove the elbow below the throttle body that the vacuum hose attaches to because the housing on the compressor side of my K27/6 was just enough bigger that I couldn't get the intake manifold seated down properly b/c the elbow hit the housing. I ended up using one of Laust's manifolds with a restrictor in the hose as a substitute.