Smoke Testing

[argniest]

Has anyone ever used a machine similar to this on their Z cars?

My cousin told me about using a smoke machine to test for vacuum leaks in the car. I watched some videos and saw some different models on ebay/amazon of several different brands of these things. I want to find someone locally who has one. So then I could have them hook it up and show me some smoke blowing out of cracks and crevices it should not BE!

They seem extremely useful to diagnose unmetered air escaping my system from wherever.

http://www.amazon.com/dp/B000P72HZY/ref=asc_df_B000P72HZY1409275?smid=ATVPDKIKX0DER&tag=hyprod-20&linkCode=asn&creative=395093&creativeASIN=B000P72HZY

Here is a youtube video about it. I think this is all real stuff. Not some made up marketing gimmic hokey video.

With something like this, I would know 100% for sure where any major and minor vacuum leaks were happening on the car.

Of course I am still so immature with my car, I dont even know where to attach something like this to the 1978 280z.

[Carl Beck]

Someone on this forum used smoke a few years ago to check their rear hatch seals etc. You might want to do a SEARCH for that...

FWIW,

Carl B.

[SteveJ]

Has anyone ever used a machine similar to this on their Z cars?

My cousin told me about using a smoke machine to test for vacuum leaks in the car. I watched some videos and saw some different models on ebay/amazon of several different brands of these things. I want to find someone locally who has one. So then I could have them hook it up and show me some smoke blowing out of cracks and crevices it should not BE!

They seem extremely useful to diagnose unmetered air escaping my system from wherever.

http://www.amazon.com/dp/B000P72HZY/ref=asc_df_B000P72HZY1409275?smid=ATVPDKIKX0DER&tag=hyprod-20&linkCode=asn&creative=395093&creativeASIN=B000P72HZY

Here is a youtube video about it. I think this is all real stuff. Not some made up marketing gimmic hokey video.

With something like this, I would know 100% for sure where any major and minor vacuum leaks were happening on the car.

Of course I am still so immature with my car, I dont even know where to attach something like this to the 1978 280z.

Just for a frame of reference, you couldn't have any unmetered air escaping since your intake isn't pressurized. It would be entering the intake.

The smoke can work as long as the radiator fan isn't blowing it away too quickly. Another old trick is to use a propane or butane torch. Let the gas out slowly and move it around the intake. If you have a leak, the gas will richen your mixture, and if you have enough gas coming in, you will hear the RPMs go up.

[gnosez]

Not meant to do the testing you have in mind (engine intake leaks),

[sblake01]

That's what I was thinking.......

[Zs-ondabrain]

It runs about $1300!!! Great buy if you own a shop. but for personal use, I'd have to rent it out to friends, just to make my money back.

Great idea though.

[SteveJ]

Come on, Dave, it's only $650. I'm still thinking that the propane would work better. The link from the OP is a tool for a sealed fuel system. Smoke candles could possibly work. I used to used those in ventilation studies. They are a LOT cheaper, probably cheaper than what someone would charge to use that gadget. As I mentioned earlier, the big problem is the fan blowing the smoke around.

http://www.grainger.com/Grainger/SUPERIOR-SIGNAL-Single-Wick-Smoke-Candles-3KLJ9?cm_mmc=Google%20Base-_-HVACR-_-Central%20Equipment-_-3KLJ9

http://www.professionalequipment.com/regin-smoke-emitters-3-minutes-5-pack-s104/hvac-sealants/?source=pegs&cid=PESEFGL

[Zs-ondabrain]

OK. The one I saw was 1300 dollars and came with a lot of stuff. All the caps, refils, fuel tank cap, lights, glasses, etc.....

The good thing about having electric fans on my Z is I can do the testing without the fan(s) blowing the smoke away from the problem....

So maybe the smoke candles would be a Sh_tload cheaper.

Dave

[FastWoman]

I keep telling people about my yogurt cup test, but nobody else has tried it. It's low-tech, but it works brilliantly:

1) Go to the grocery store, and buy a 50 cent cup of yogurt.

2) Go home and enjoy the yogurt, as you ponder the task ahead.

3) Rinse and dry the cup.

4) Remove the AFM.

5) Stuff the yogurt cup into the AFM-to-throttle boot, thus sealing it.

6) Pull off the brake booster vacuum hose, and put another clean hose on it.

7) Put the other end of the hose in your mouth, and blow, so as to pressurize the intake. Then hold the pressure with your mouth. The pressure will slowly leak down. Note roughly how long it takes.

8) As a frame of reference, pull a small vacuum line off, and repeat the test. Air should escape remarkably faster with the small vacuum leak. If this difference is remarkable, then the sum of your leaks (including valves, rings, etc.) shouldn't be any larger than that one small vacuum leak you created, which wouldn't be particularly significant by itself.

Cheap

Fast

Easy

Conclusive -- allowing you to answer the "do I have a vacuum leak" question and move on.

Please PayPal me all the money this method would have saved you.

[cozye]

A smoke test does work to detect intake leaks, but you do it with the car off.

By placing the whole intake system under a small amount of positive pressure with a smoke source, any leaks theoretically will reveal themselves when you see the smoke coming out. You will have to seal off the throttle body opening however, as the smoke will just flow up through the air cleaner if you don't and not get trapped enough to reveal leaks.

I've done it. I made one from a "fog machine" I acquired at target for $24 and I used a series of difference size hoses to adapt it to the brake booster port on the intake.

I didn't have any intake leaks, but if I pulled off even the smallest vacuum line smoke would come out so it should work as long as you can see all areas around the intake. If you have an intake leak around the bottom of the intake gasket, it could be difficult to see without a small mirror and a light.

I do agree however that the propane testing is probably more effective. I've tried all of the different ways to test (carb spray, boost test, smoke test, propane, a similar version of sarah's yogurt cup test, etc..)

Take a propane torche, put about 18" of hose on the end of the nozzle, and turn it on with the car running and blow it all over any fittings, gaskets, boots, etc.. do it slowly. It does work good. You can pull off an ac vacuum line to test it, the car will rev up significantly with propane introduced into the intake even as far away as the air intake on the other side of the air filter.

[cozye]

and for all the people saying that the fan blows the smoke around,, again, you do a smoke test with the car off.. duh....!!!

[FastWoman]

I've tried all of the different ways to test (carb spray, boost test, smoke test, propane, a similar version of sarah's yogurt cup test, etc..)

Ah, but you used duct tape, Eric! Not nearly so elegant as Yoplait!