vacuum hose on stock upper intake? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

blueoval · 11-18-2003, 20:11

Can anyone tell me what the vacuum hose underneath the upper intake manifold does? Its in the shape of a walking stick and apparantly mine is perished and cracked. Would this have anything to do with my idle speed?

C0V3R · 11-18-2003, 20:38

The cracking could cause a vacuum leak. Ideally it should be replaced.

blueoval · 11-18-2003, 20:50

It is. thanks COV3R. I just need to know it has any relation to the way the car idles.

C0V3R · 11-18-2003, 21:08

It if it is leaking it could affect the way it idles, as well as the way it runs throughout, however it would be most noticable at idle. Youre likely to be getting extra air that is not measured by the MAF, and may run slightly leaner/faster.

blueoval · 11-18-2003, 21:30

hehe. You know, I have spent the past 2 years finding out why my car has erratic idling and you know what?........Nobody could ever find the problem. Ive had it on the dyno so many times that in the end I could buy own. The car seems to want to idle around the 800-1000rpm mark in drive and in neutral the tacho flies to over 1200-1500rpm. I try to turn the car off for 20-30seconds and restart it and it seems ok for a while in traffic, then up it goes again once I pull up to a stop. Its been driving me nuts.

I have been told its the dizzy, the oxy sensors, the maf, the air cleaner and none of them are willing to lay their cash on the table to prove it. Their dyno has claimed every other problem but this dicky piece of rubber which lays dormant till I get the intake manifold replaced.

This (hopefully) will be the answer to this pain staking and annoying glitch I've had for such a long time.

C0V3R · 11-18-2003, 22:10

If its leaking very badly then occasionally sealing for whatever reason it would explain alot. My car will still run with a vacuum port unplugged, but it runs quite poorly. I never investigated the possible symptoms fully, but bouncing idles point to vac leaks, stuffed spark plugs and or ignition issues, dirt or grime on the MAF or o2 sensor. I'd replace the hose first, see how it goes, then if its still no good check the plugs and try cleaning the maf.

blueoval · 11-18-2003, 22:41

yeah that was the next thing I was planning to do was the maf. spark plugs have been fine, i replace those every 10k. As far as the hose is concerned, I am replacing it but the part is coming from melbourne. If that doesnt work I'll look to other things!

blueoval · 11-20-2003, 15:42

well, i got the car back last night.

That vacuum hose cost a fortune - $75?

The out come of it being replaced is a much smoother idle and no idle hunting. yay!
Finally I have solved this problem that has been haunting me for the last 2 years. Time to concentrate on other mods now!