Vacuum leak, How to find? - Toyota Nation Forum : Toyota Car and Truck Forums

speedyts49 · 09-18-2005, 02:55 PM

I think I have a vacuum leak SOMEWHERE in the engine system. I have replaced all of the emission parts so I know they are good. The car fails a test that should show high vacuum when revved to 2500 rpms with the r port hose removed from the vacuum modulator and hose connected from that same port to the throttle body vacuum port. I get no vacuum on my gage which is spliced betwwen the egr and vsv with a Tee.

I checked that routing was correct on all EM system hoses.

I must have a leak somewhere and just would like some advice as to how to find it.

Pineapple · 09-18-2005, 09:25 PM

Get a can or 2 of throttle body cleaner spray. Start the engine and spray the clearn around intake manifold and all vaccum hose. Include power steering and brake booster. When you get close to the leak, the engine will stall. If you spray right into a big leak, engine will stop.

TeRcElIcA · 09-18-2005, 09:42 PM

I used brake cleaner, that works too right? considering it worked for me

89CelicaGTTurbo · 09-18-2005, 09:49 PM

dont use brake parts cleaner. parts cleaner can actually melt some plastics and can take off paint. plus, parts cleaner dosnt have any oil. carb cleaner or throttle body cleaner is the best thing.

also check the two vac lines going to the power steering. it gose to the bottom so its hard to locate

TeRcElIcA · 09-19-2005, 02:16 AM

hmmm... guess I was lucky then huh...

... I actually don't remember whether it was carb cleaner or brake cleaner... I just remember it was a cleaner... THANKS!...

speedyts49 · 09-19-2005, 07:44 AM

Quote:

Originally Posted by 89CelicaGTTurbo

dont use brake parts cleaner. parts cleaner can actually melt some plastics and can take off paint. plus, parts cleaner dosnt have any oil. carb cleaner or throttle body cleaner is the best thing.

also check the two vac lines going to the power steering. it gose to the bottom so its hard to locate

I'm gonna replace those two hoses cause they looked pretty bad when I checked them last. How about a brake booster vacuum line? I have not checked that yet and am not sure where it is.

Is WD-40 ok to use or is throttle body the best?

fredk · 09-19-2005, 08:28 AM

this works good too, get a pair of pliers and start squeezing all the vacuum hoses just past where they come off the intake manifold and listen for a change in rpm

flex-appeal · 09-19-2005, 10:16 PM

If your taking the time to remove and check hoses, i say just change them all.. 4mm vacuum hose was like 2.99 a metre last time i checked and you will feel better off knowing that you have eliminated that potential source of troubles for the next few years.
Im halfway through replacing mine, my car is smoother at high rpm after changing the vac hose on the throttle opener even though the original one appeared to be perfectly ok, sometimes small leaks arent that obvious - total cost so far 5.98

fredk · 09-19-2005, 10:33 PM

go to napa and get a few feet of hose and change all those little suckers

speedyts49 · 09-19-2005, 10:36 PM

Quote:

Originally Posted by flex-appeal

If your taking the time to remove and check hoses, i say just change them all.. 4mm vacuum hose was like 2.99 a metre last time i checked and you will feel better off knowing that you have eliminated that potential source of troubles for the next few years.
Im halfway through replacing mine, my car is smoother at high rpm after changing the vac hose on the throttle opener even though the original one appeared to be perfectly ok, sometimes small leaks arent that obvious - total cost so far 5.98

That is what I have done so far. At least all the EGR related ones. I'm pretty confident that they are all good. The power steering and any brake vacuum will get changed next. If that doesn't do it then I will go with throttle cleaner. There is a leak somewhere or the ecu is bad which would be a pretty bad deal.
Whats amazing is all the bad sensors I have found on this car.
The EL came on again today.
My fortune cookie last night said "Nothing in the world can take the place of persistence" and that is true in this case for sure.

speedyts49 · 09-20-2005, 06:35 PM

I have no leaks that I can find using the throttle body cleaner method. I replaced the two power steering vacuum hoses. Its like the VSV is not getting the signal.
Could a plugged up throttle body cause these darn problems?
There are two big hoses coming off the throttle body that could be a problem maybe.
Maybe the mechanics that worked on it last unhooked something electical to my VSV, now i'm getting paranoid!

My neighbor whom is a dealer mechanic suggested pulling the throttle body and cleaning it which I might do. If some of the orifices are plugged I suppose that could be a problem.

flex-appeal · 09-20-2005, 09:05 PM

not sure which ones you are referring to, but the big hoses are probably coolant lines.

speedyts49 · 09-23-2005, 10:23 PM

I found a port blocked on the throttle body. I wil check it ot on saturday

speedyts49 · 09-24-2005, 01:53 PM

Turns out the middle port on the throttle body was plugged which caused it to fail the vacuum test to the modulator.
Hopefully fingers crossed knock on wood the EL will not come back on.
I shot the crap out of the port with throttle body cleaner and did not have to remove the whole thing.