Vaccum leak..?

[RiceRocketDSM02]

I posted before about what my vac pressure should be at idle and they said 20hg. BUT at idle mine is at 15-16hg. When I drive and let off the gas but stay in gear it'll drop to 20hg but when I push in the clutch, it'll go back up to 15-16hg. Is it a vac leak?

Second, I did some research but didn't really find the fix. But my car will also idle radically. It'll be at 700 for a sec and then jump up to 1000, then drop back down... it never stays steady. Is it my ISC, throttle body sticking, TPS sensor? If anyone can inform me on this would be lots of help. Thanks

 

[Whiplash]

Test you ISC. I have the same problem and I tested my ISC. It was fine, but it looks like my O2 sensor needs to be replaced.

Does your car run rich or does it run fine?

 

[95AWD_TSI_TALON]

Either your timing belt is off a tooth or you have a boost leak. (causes the VAC to be low)
matthew

 

[RiceRocketDSM02]

Test you ISC. I have the same problem and I tested my ISC. It was fine, but it looks like my O2 sensor needs to be replaced.

Does your car run rich or does it run fine?

My car runs rich... Thanks for the info by the way... Anybody have any solutions for the idle not being steady?? I was thinking that the problem was having the stock fpr with 550 injectors and 255 fuel pump... yes?...no?...maybe?

 

[Whiplash]

Its possible. Do you actually hear the vacuum leak? If you do then try pinching all the vacuum hoses until you hear it stop. In my case its the intake manifold gasket thats leaking.

 

[RiceRocketDSM02]

I was driving to work today and I noticed that the vac pressure was at 20hg at idle sometimes and then sometimes at 15-16hg. I don't understand.. I'm just thinkin' bout taking my car in and getting everything fixed on my car that needs to be fixed. I rather just take it in for problems and just do the mods myself...

 

[majestics94rage]

I just had this same problem, mine was a combination between boost leak and the spark plugs being gapped wrong. I had a boost leak in my uicp where the bov is, this caused unsteady idle and had the vac acting crazy. After fixing the leak the vac problem was fixed but the car still idled a little rough, so I checked the spark plugs and found out that the shop where my car was worked on felt that they needed to gap the plugs at .040 or something close to that, after proper gapping the car runs perfect.

 

[RiceRocketDSM02]

I just had this same problem, mine was a combination between boost leak and the spark plugs being gapped wrong. I had a boost leak in my uicp where the bov is, this caused unsteady idle and had the vac acting crazy. After fixing the leak the vac problem was fixed but the car still idled a little rough, so I checked the spark plugs and found out that the shop where my car was worked on felt that they needed to gap the plugs at .040 or something close to that, after proper gapping the car runs perfect.

Thanks for the help... I'll check it out and see whats up