Has anyone ever found a TPI vacuum leak? I know I have one, because it idles like shiit. But I can't find it. Took the runners apart 2 times already. Replaced everything more than once.
Anyone create a smoke machine.

 

A smoke machine is probably the only way you can test the majority of possible leak places on a tpi. New ones aren't all ridiculously priced like they used to be but still $200 is $200. For the most part, mine is just a grill regulator, a paint can, heating element, and hoses. But that can be simplified down since mine is using an air compressor. This video I ran into is the most simplistic I've seen but it's better than blind guessing with carb cleaner like it's 1975.
Do a google search, lots of people have ways to make them. For whatever reason, a lot of 3rd genners are afraid of them like it's too much work, a "honda" thing or voodoo magic. There are leaks I never would've found without it, even on my old carb'd 400.

 

$200?? I picked up a very basic unit on Amazon a couple years ago for $90 (it does require an external air source, and it runs off the car battery). Works very well.


I'm sure you can make one for less but either way I'd say a smoke tester is a must-have especially for older cars. I've found a few pieces of vacuum line with leaks that weren't visible to the naked eye, and it's already paid for itself in time saved on those jobs.

 

I went looking for that exact one in a 1 minute search and didn't find it immediately. Needs an air compressor too which negates the price if you don't have one.
That's when I found the more professional/less diy versions were down to $150-200. Beats the crap out of the $900-2000 they were all at before.

 

True, if you don't already have an air compressor it's not really a savings, but I assume that most folks have one available.

And I see what you're saying now, the high end ones used to be much more expensive but the price has dropped. $200 doesn't seem that unreasonable for something higher quality (although they seem more geared towards heavy shop use).

 

I used a pack of cigarettes, and that hand pump. Beware, you will have nasty tar buildup in whatever port you pump smoke into. I used the TB port, so I had to clean my TB afterwards.
No vacuum leaks !!! hence, my car still idles like shiit.

 

Have you followed the vacuum lines to

the HVAC / the vacuum canister under the battery tray?

I found that my line was kinda dry rotted at the connection that connects to the canister and the cruise control.

 

I put vacuum caps on every port on the plenum. Idle still hunting all over.

 

Disconnect the est, does it still hunt? What's the base timing at? Try advancing and retarding it, see if the issue changes.

 

Timing has never been fuucked with, or even checked. Original owner.

 

Did you try soraying some brake cleaner or something atthe bottom of the intake / heads?

I recall something that the gaskets like to leak and create vacuum leaks there.

 

I did the smoke test... nothing.

 

So check it, check the fuel pressure, get some sensor data out of the aldl port. Take a look at the spark plugs. You've gotta get some more data if it's not vacuum leaks. Can't use process of elimination without factors to eliminate.

 

Fuel pressure is fine. 40psi at idle. 47 without vacuum. Data is fine. BLM's in line. MAF fine. IAC steps fine. No codes. Runs amazing from 1000 RPM to red line.

 

Hmm, how often does it occur? Only cold, only warm, all the time? Does it get better or worse at times?

I'd be curious about how it runs with est disconnected. Otherwise I'm suspecting things like clogged injectors, broken egr system, cracked throttle body, something a little unusual.

 

New injectors, new EGR, new TB, new TPS, new IAC. Only in closed loop.

 

O2 sensor? Exhaust leak messing with o2 sensor? Do you have stock manifolds, or headers?

 

The car is 100% oem except a cat-back. and injectors.