Greetings.

A couple of things.
Any help would be greatly appreciated.

Can someone identify the tube/hose highlighted in red on the attached image? All of the terminology I've used to describe it brings up wrong or no results. I need to replace this part on my car - It is very loose where it connects to the engine and I suspect it is the source of my vacuum leak woes.




2nd question (which I suspect is related to the first):

I have a 96 Monte Carlo LS 3.1 that sputters, lunges, and dies randomly (rpm jump all over the place) when I'm driving. I can generally restart it right away after it dies. When It doesn't start right away the only way I can get it to start again is by flooring the gas pedal (which cant be good on the engine I imagine).

I cannot pinpoint the exact conditions under which it has the problem but It has done it to me on cold starts, hot starts, making turns, accelerating from a stop lights, and just general driving. In short its unpredictable.

Things I have done:

1. Replaced the PCV and its corresponding hose. It definitely helped (The hose was old and loose where it attached to the engine) but the problem returned after a few days.

2. I replaced the MAF. The problem remains the same/worse.

3. I checked to see if there was any gas leakage at the fuel regulator valve and I don't see any.

Diagnostic codes I'm getting are P0102, P0106, P0108 and P0300. The common denominator is a vacuum leak which is how I'm approaching the problem before I start dumping more money on other things.

 

Jotz:
Welcome to the forum.

In reference to the 3.1 Monte,
When you changed the MAF... Did you use an AC Delco MAF?? if u used the cheaper bosch or 1 from ebay... Neither is good... That could be the problem... always replace things like a MAF with OEM AC Delco parts.

A quick test if... the MAF is in fact the culprit... unplug it... start and drive it around the block.. If the problem/running issue disappears... Then it was the MAF...this test doesn't always resolve the issue...But it will tell you that its the MAF!

Hope this helps maybe someone else will chime in with more ideas...
Good Luck!

On identifying that hose in "RED" what motor/vehicle is it?

 

Where dose it connect to the engine. I have seen it be 2 things. On my 02 and on my now junked 98 Monte, it housed the harness for the Air Density Sensor. Much older cars it was just a hose that supplied air into the IAC. Does it have wires inside or is it just a hose?

 

Thanks for the input so far.

I will give the MAF sensor test a shot. The MAF I bought was from Autozone - could be a Cardone or a Duralast.

As far as the hose is concerned:

It's just a rigid tube/hose. No wires inside. It actually cracked when I pulled it off . The part where it connects into the engine is entirely worn off. The seal appears to be completely worn.

It goes to the to top of the top/back of the engine (I'm not a mechanic cant really tell you the exact part) to the manifold (?).

Could the hose be the cause of my probs?

 

autozones cardone or duralast...shoul never be used to replace the MAF... I highly recommend replacing it with an AC Delco Maf.

A vacuum leak is always a problem.... Like JC mentioned it could be (the red hose) IAC (intake air control) type setup. Such causeing a variance in the reading to the Maf, whether its cold or hot while its running its constantly making changes to the system... since it connects to the intake tube...its a definate possibility?

Either way... I would still change the MAF to the AC Delco regardless...
They both could be contributing to the problem.

 

If it is a rigid hose then it is a Vacuum or Breather line. Either way it can cause many problems including rough and erratic idle!

 

I'll look into an AC Delco MAF

Didn't see your question about type of engine on your post.

96 Monte Carlo LS
3.1 V6

Here's a pic of the tube/hose in question.



What would you guys call this hose?

Thanks for the help.

 

Here is your problem.

P0102 = MAF
P0108 & P0108 = MAP
P0300 = Random misfire

Your MAF is bad unless you didn't clear codes. Your MAP sensor is either bad, or is missing the vacuum line to it/line is cracked.

 

Thanks John for the Great info!
And clearing this mystery issue up!