Finally got my idle consistent this weekend after running down what seems like a dozen vacuum leaks.

I was diagnosing with carb cleaner and found one on the main flexy rubber intake hose that is on the intake side of the throttle body.

It has several cracks (on the firewall side so not visible) that started on the lip and ran right under the clamp.

Got a new one at the stealer ( I get Toy parts at wholesale due to a company tie in) and they had 5 in stock. Chatted to parts manager who said that they get brittle with time and after a certain number of miles, its almsot impossible to remove them without cracking/tearing them.

Anyway, after I installed it, idle does not move at all and also about 50 rpm lower.

If you are chasing a vac leak, have a close look at your intake hose....

David

 

have you done the sea foam thing?

 

Good to hear you found the problem!! I know how good that feels!

You may want to rethink using carb cleaner to find air leaks. Try wd40 next time.

my 2 cents.

 

carb cleaner is much more flamable than wd40, so when you spray it around a leek its much easyer to hear the idle pickup than with wd40

 

Ya, I understand why it's being used. all I am saying is it's not the best idea.
in my humbled opinion

 

You are 100% right and I am lazy....

It is more flammable and also more likely to damage sensitive parts...

I will not do the seafoam thing as I am using a very high quality ( next generation, develped by my company, prolly in street gas in 06 ) fuel system cleaner that I am dosing into my fuel myself.

I know that does not get the 'air' side of the intake system but I am a little leary of seafoam... you are using a lot of solvent to get the goods into the right spots and that worries me in respect of old seals etc.

I plan on removing the inlet manifold soon when I do the valve shim job so I will have the entire thing chem cleaned at work.

David