questions about pressure test, fuel cut, python injection

[mhuffman]

1.) when i did my pressure test, the engine only held pressure for a few seconds before it depressurized, is this normal?

2.) I get a moderate to severe engine cut out under full throttle above 4k rpm's. I have already done correct plugs, ingition wires, and checked for boost leaks. Only mod is turbo back exhaust. It feels like a misfire sometimes but other times power cuts out completely like fuel cut or something. The MAF is unmodified. None of the 'free mods' are performed. car runs fine at any less than WOT, and the car has very strong power until the 'problem' kicks in. Any ideas?

3.) Why does my PCM in my dash say 'python injection' and have a red sticker with a snake on it? WTF

 

[Phantom DSM]

Sorry if im butting in to this thread, but i'm having the same problem right now in my car with condition #2. My car was running perfect with a stock BOV and stock piping with a 16g but still on stock boost control solenoid. Last week i switched to some welded upper intercooler piping and a Turbo XS RFL-H. Im blowing off my lower piping all the time off the SMIC. I cant afford a bov right now, but im almost positive that the XS is leaking. The car wont do a full WOT sweep and you have to shift it to the next gear, other than that it runs fine.

Lets see if we can help each other that way: do a boost leak check, and see if your bov is leaking. Im assuming you are runing low boost also, and asking why your getting the "fuel cut" feel and stutter above 4k under full throttle. This is so frustrating If anyone could help, we would appreciate it.

 

[mhuffman]

Sorry if im butting in to this thread, but i'm having the same problem right now in my car with condition #2. My car was running perfect with a stock BOV and stock piping with a 16g but still on stock boost control solenoid. Last week i switched to some welded upper intercooler piping and a Turbo XS RFL-H. Im blowing off my lower piping all the time off the SMIC. I cant afford a bov right now, but im almost positive that the XS is leaking. The car wont do a full WOT sweep and you have to shift it to the next gear, other than that it runs fine.

Lets see if we can help each other that way: do a boost leak check, and see if your bov is leaking. Im assuming you are runing low boost also, and asking why your getting the "fuel cut" feel and stutter above 4k under full throttle. This is so frustrating If anyone could help, we would appreciate it.

Hey man, i put NGK's in there and i still had the problem, but i took them out and gapped them to about 0.028" from 0.032" and the misfire is less / possibly gone. I would check the gap on ## plugs. I still think i have a weak coil...

 

[oldman]

1. Disable your mbc.

2. Turn your motor to 30* ATDC to avoid valve overlap.

3. Start your test at the TB elbow and focus on area behind the TB first.

4. Spray soapy water at TB gasket, BISS, TB shaft on both sides, IM gasket, injector insulators, brake booster, afpr and all vacuum lines/connections.

5. Open your oil cap and listen for leaks. (PCV, valve seals/guide, rings)

5. Listen to your tailpipe for leaks. (EGR, valve overlap, jumped timing, bent/unseated valves)

6. Once all leaks are fixed, move the tester back to the turbo inlet.

7. Spray down the compressor cover (known leak), BOV return/flange (DO NOT TAP YOUR BOV LINE FOR YOUR MBC!!!), IC end tank/fins and all connections. Re- test.

8. Note that you will leak air into the crankcase through the turbo seal but do not panic, this is normal during a static pressure test as long as there are no shaft play.

The desired test result from the begining of the LICP (bypassing turbo) is around 20psi (on boost gauge) with the compressor set at 30psi, while taking no less than 30 seconds to bleed down to 0.

As a reference, my last test on my 500 mile new engine, I was able to pressurize the system to 25psi, bled down to about 16psi (my 1G bov) in about 30seconds, then took about 3 mins to 6psi and just kinda lingered there for a while. It's not easy to do but the point is it's possible. My next goal is 30psi After motor break in and Dodge modding my BOV. A boost leak test is one of most pita but important regular maintenace task, the key is patience and endurance, have fun.

Something I posted yesterday.

Phantom DSM, are you tapping the BOV line for your mbc?

 

[Phantom DSM]

right now im still using the stock bcs restrictor. To be honest with you guys, i just opened this turbo xs Bov that was used and it looked like shit. The spring was rusted and it looked like the bov had mud in it, and the guy i got it from ( it was free ) said it was out in the weather for a while. But you know, even if it was leaking im still gonna check the plugs, their probably foul by now. i put back my stock bov and piping and it runs fine. I guess either i was spiking, or these plugs are bad from being too rich on open bov .
Thanks oldman for pitching in the wiseman advice