A/F ratio when idling?

M

McMsk

New Member
Mar 28, 2006
35
0
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Germany
well most that i did, was install a big turbo and fmic. then i startek setting it up and noticed that i had a pressure leak, which came from a broken greddy bov on the hardpipes. This is now closed with a metall plate. then i was able to boost higher, because before that i was not able to boost more than 0.8 bar, then the boost controller would show an odd behavior. after closing it with a plate it worked much better and i was able to boost up to 1.3 bar without fuel cut. And now it behaves shitty again.

So i built the pressure tester and found out my stock bov was shitty. But now it still is odd, but since i removed the stock bov as well i have fuel cut again.
 
isnms

isnms

United States of America
Mar 30, 2005
2,145
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Oklahoma
i80.photobucket.com
^cool, can you share how you built yours?

I could have bought one by now. I've actually taken it in three times now for then to hook it up. It's so much easier finding leaks that way.
 
IHI-RHC7

IHI-RHC7

"The Boss"
Apr 1, 2005
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Oregon
That is odd, with a bad leak, you would hit FCO at a low boost. Fixing the leak should not have made you hit FCO at lower boost levels, unless by fixing the leak, the next weak link broke.
That is, now that the hardpipes are holding boost, you blew out your intake mani gasket. With AFRs acting like they are, you should be able to hear the intake manifold sucking in unmetered air while idling.
 
M

McMsk

New Member
Mar 28, 2006
35
0
0
Germany
well the engine idles shitty anyways because i might have bhg, but once the car heats up, the idle is better. Therefor i am not quite sure what it is I hear. The broken gasket would not have to be very broken to be causing this, or?

How does a smoke mashine work, never saw one yet. Can i build one easily to figure out my problem?

Thanks
 
jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
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Redacted per Title 18 USC Section 798
A smoke machine pressurizes things with smoke. Leaks in the induction system, vacuum lines, exhaust system, under dash lines, almost any leak in a sealed volume can be quickly found by looking for the smoke escaping. Some even use smoke that glows under UV light. They're a very handy tool.

The things are expensive though, especially the new ones that do EVAP testing. You can get a "regular" one for around $500. My Gas analyzer and lab scope cost more but I use them more often too so building a smoke machine was the only logical asnwer to buying one. It's not something you're going to whip up in an afternoon and does take some fabrication skills but if you're creative building one isn't all that difficult.

Lots of ways to do it. Mine uses a cheap 110 volt tire air compressor (you can use an even cheaper 12 volt one and run it off the car), a regulator, and a small sealed tank that has a simple hand wound wire heating element half submerged in the smoke fluid. The compressor is connected to the heater and pressurizes the tank after the heater has generated smoke.

A deliberately underated inline auto resetting circuit breaker cycles the heater and another protects the tank from runaway. An adjustable flow valve controls the output but the pressure also needs to stay low to protect things you're testing. 5 psi or less is good enough. The tank also has a small pop off valve just in case. As a former machine design engineer I'm somewhat embarressed by this contraption but it does the job. I'm going to make it nicer at some point. You can get the smoke fluid from Snap On and other places or even whip up your own.
 
M

McMsk

New Member
Mar 28, 2006
35
0
0
Germany
Will it not work if i buy some smoke fluid, which is used like for discis and clubs or so, and then somehow feed this smoke into the compressor i am using? Then the compressor shhould be filled with smoke, so much for the theroy, but have no idea if this works and how best to connect the fluid to the compressor.

Well neverthe less now i am looking for to checkin´g out my car tomorrow as i extra went ad bought this special spray, to check out pressur leaks. I first thought of using it with the engine in, but the stuff will only detect overpressure leaks i guess, so i will have to go back to my pressure tester.

By the way, how do you guys close the holes on accordeon hose, like where the stock bov goes?
 
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