Needed: Exhaust smoke leak checker thingy

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SDarkRage

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Anybody in the OKC area have a smoke tester for automotive exhaust systems? I’m trying to pinpoint a leak in my exhaust so I can get my EFI to work right again. If anyone has one I can borrow for a few minutes, I’d greatly appreciate it.
 

Dumpstick

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Jack the car up, put it on stands. Take off the air intake hose, seal the throttle body inlet with duct tape.
Rig up some sort of air hose connection at the exhaust tailpipe, using PVC, duct tape and a screw in connection.
Run the compressor to about 30 psi. Connect the hose to the tailpipe.

Get underneath and listen. Cut a 3 foot piece of 3/4" heater hose or garden hose to use as a stethoscope.

Cost less than $10, maybe less if you have some of this stuff already.
 

SlugSlinger

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How do you know there is a leak? Is the computer throwing codes?

I do the same thing^. I run my hand along the exhaust and focus on the connections and keep my hand about an inch away from it. You can feel a leak. Normally it will be leaking from a hole in a weld, so start checking the welds at each connections.
 

SDarkRage

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It’s a Holley Sniper EFI which doesn’t throw a “code”, it will just start running richer until it fouls plugs or washes out the cylinders from too much gas. Exhaust leaks before and a little after the O2 sensor cause the system to see a lean condition so it keeps adding fuel to correct it.

The exhaust is new from headers to the tips so it’s rather hard to hear it when the truck is running. I want the smoker so I can see if there is multiple spots. Doesn’t take much more than a pinhole to screw up the reading.
 

swampratt

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I'm surprised it's that sensitive. Good luck with the search.
Very sensitive O2 sensor any small leak or misfire will give a lean reading and begin to richen up the mixture.
Make darn sure the spark plugs are all clean not black and sooty after each thing you fix.
Like tightening the header flanges after going rich. Pull all spark plugs and make darn sure they are clean.

Too wide of a gap can cause a misfire also.
I would set gap at .035 for initial running and testing.
Not .045" or larger.

If it is supercharged or Nitroused I would tighten them a bit more.

My corolla calls for .032" and it misfires but at .025-.027 it does not.
 

John6185

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Jam a potato up the tailpipe. Listen for the leak. If you have one it will be evident. If you have no leak the potato will be blown out with a great noise.
 

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