Vacuum leak..

REDDYZ · 09-02-2012, 07:04 PM

Throttle hang + Poor mileage + loss in power = Vacuum leak.

After doing such and extensive work on engine I was thinking what could possibly go wrong in near future? Well, its hardly a month I had good time with my kat without any hassels. Now there is a vacuum leak somewhere thats drawing excess air while idling causing rpms go over 2500. Searched everywhere for leaks but no luck.

I could hear the leak but couldn't find where. Wasted a spray can of contact cleaner but couldn't trace the leak. By passed oil catch can but didn't make any difference.

I don't know if it is co incidence or consequence day before yesterday I found instrument cluster and dvd player were reset on its own. Then after a while it happened again. After a bit of investigation I found the accessory cable on positive battery terminal was loose. I couldn't figure out how that happened. Couldn't make it tight or loose. Eventually I snapped the bolt and bolted that cable on the main bolt that locks terminal onto battery.

Since then idling has changed. Every time I depress clutch or shift to neutral rpms goes over 2000 and drops down after few seconds. Mileage has gone from 8.9L to 14.5L. Replaced IACV and disconnected TPS plug while engine running which didn't made any difference.

I think its time to strip things around engine..

Cougar2K · 10-02-2012, 12:30 AM

Hey Yogi,

Sorry to hear about your troubles there!

That's a hell of a blow out on the mileage.

Here I thought I had my own lil gremlins to deal with occasionally but seems one has cropped up into your engine bay too now!

Well at least with you personally having recently stripped the engine right back, you'd be in the best position to hopefully identify where this problem lies or has come on from after all...

Best of luck with it and here's too a speedy recovery back to the good times again!

falconhell74 · 10-02-2012, 07:22 AM

Probably wrong but is your air flow meter playing games? just a thought

REDDYZ · 10-02-2012, 07:54 AM

Quote:

Originally Posted by Cougar2K

Hey Yogi,

Sorry to hear about your troubles there!

That's a hell of a blow out on the mileage.

Here I thought I had my own lil gremlins to deal with occasionally but seems one has cropped up into your engine bay too now!

Well at least with you personally having recently stripped the engine right back, you'd be in the best position to hopefully identify where this problem lies or has come on from after all...

Best of luck with it and here's too a speedy recovery back to the good times again!

I feel like am maintaining a V8 now. I wouldn't worry much as am confident its vacuum leak. Since I did engine by myself am confident that engine part has no issues. Yesterday I used contact cleaner to check around LIM & UIM gaskets which has no leaks. Its definitely the vacuum hoses running around engine. I will definitely find it soon. Thanks & I hope my kat will be normal soon.

Quote:

Originally Posted by falconhell74

Probably wrong but is your air flow meter playing games? just a thought

Airflow meter is not leaking, I checked it. To check its functionality I have to hook up scan tool later today to see if it is playing up. Its definitely leak though. I can hear the leak but can't trace. I could hear from sides and top.

thearrow · 10-02-2012, 02:31 PM

If you have a vacuum leak you can bet it will be the source of ALL your troubles.

Find the leak and you will be OK.

I sprung a leak one day on the Harbour Bridge and was lucky I wasn't killed.

REDDYZ · 11-02-2012, 01:31 AM

Quote:

Originally Posted by thearrow

If you have a vacuum leak you can bet it will be the source of ALL your troubles.

Find the leak and you will be OK.

I sprung a leak one day on the Harbour Bridge and was lucky I wasn't killed.

I think over the period of time vacuum leaks are inevitable on cars. Unless you park your car in lockup garage all the time.

I know that theres vacuum leak on my kat as I can hear it and there is throttle hang as well. So, I tried to wiggle and later pulled all vacuum hoses to see if they are loose. One of the hoses didn't feel alright so, pulled it a just a bit hard and it came off. It was partly holding and partly off.

This was the culprit. The vacuum hose that was off.

It runs along firewall behind engine and connect to HVAC that is mounted on firewall. On some kats it is mounted in UIM. Its hard to see it and accessing it is far thing.

Fixed that hose and everything is back to normal. No throttle hang, no over revving, no leak sound. Reset the ECU so that it forgets that it use to and has to pump extra fuel.

What a relief... all happies now