Loud Popping sound and black smoke out exauhst during 3rd gear pulls

[JCHemenway]

So ive encountered this issue 3 times now and it has scared the Hell outta me . During a 3rd gear pull i will Floor it at about 3-4k Rpm and boost will raise to a steady 9psi at about 5.5k rpm my psi will increase to a steady 15psi and pull hard close to redline but before i reach the end of 3rd gear a loud POP will present itself and i lose all engine power for a split second. Ive never kept my foot on the pedal but when i do put my foot back down and drive it like normal it acts fine, it will even do another pull again. My friend was following me once when this happened and said a huge cloud of Black smoke shot out of exhaust and it had a burnt smell to it Not fuel or anything. A quick question about my turbo while im at it. As i stated my psi will sit at 9 then jump to 15 at around 5k and hold steady there. I know i got a small boost leak at the TB but my question is that the previous owner told me it was set at 15 psi. How would he go about setting it to 15 psi, theres no manual boost controller and the wastegate dont seem to be adjustable, it is the stock 14b btw. what could be atributed to my weird boost levels and what could cause this horrible lose of power and black smoke during the pop sound.

 

[96awd16g]

Sounds like fuel cut
I even get a good flame under fuel cut, although thats not something to brag about.

Porting if its caused by boost creep, Boost leaks can help it happen, or less boost.

 

[-Boosty-]

popping def sounds like a lean condition, do a BLT, and go from there. also check your manifold for cracks or leaks around the gasket, my header had about 5 leaks and caused some creep and such. If he has the wastegate running off the intercooler pipe chances are its set to stock boost, and he probably mistook the creep your having, as having it set at 15psi.

 

['97 Cayenne]

I agree with the above statements

 

[thomyd]

check knock ret for mis fires too!

 

[JCHemenway]

Yes the WG is running right off the J pipe with nothing inbetween i ordered myself a cheap MBC for now but havent installed it because if it is boost creep and i set my psi higher that means that i will get higher creep right? How would i go about looking for Manifold/Gasket leaks? Can boost leaks cause me to hit fuel cut or just high amounts of boost under WOT?

 

[Aphix]

Turning up the boost could possibly create higher creep. It's hard to say, what is happening in your turbo exhaust isn't being rerouted sufficiently enough to control boost. When this happened to me it was due to my wastegate actuator arm not working smoothly. It can also be from running a 3" turboback exhaust sometimes, or even a leaky vacuum line to the wastegate.

What I would first do is check that vacuum line, make sure it is not leaking. Then I would pull the wastegate actuator linkage off and make sure it isn't adjusted in too far (you have to pull it pretty far to get onto the wastegate arm, then it should be adjusted out), because this can cause a shorter throw in your wastegate, leading to boost creep. While its off I would also doublecheck your wastegate is working smoothly.

Now as far as boost leaks causing fuel cut, this isn't particularly true. Fuel cut comes from the car attempting to save itself from injector duty cycles being overran (correct me if im wrong?). Boost leaks will cause a rich condition due to air volume leaking out. Which may be causing your backfire.

 

[bjmauck]

Sounds like fuel cut.

 

[JCHemenway]

I havent had my turbo off yet but i see no adjustment on the WG arm. This michigan weather is ridiculous and its cold outside for now but i just got my new Intercooler piping and greddy type s BOV in the mail. Gunna inspect it all when i have it apart

 

[-Boosty-]

I havent had my turbo off yet but i see no adjustment on the WG arm. This michigan weather is ridiculous and its cold outside for now but i just got my new Intercooler piping and greddy type s BOV in the mail. Gunna inspect it all when i have it apart

Just noticed your from MI too, i live in kzoo. I had my boost set to stock, and it was creeping all the way past 20lbs where it then hit fuel cut. That was on rc550's. Fuel cut is basically your engines defense to overboosting, once it see's more air then it can supply fuel to, it cuts it to prevent your turbo from spinning into oblivion. Dont expect your motor to handle fuel cut well tho, you'll find yourself replacing the whole thing if you keep doing it. To check for manifold leaks your gonna have to get it off and look. I dont see spraying something on it working unless you do it super quick when u first fire it up and its still cool enough for that 10 or 15 seconds to not evaporate the soapy water. Its supposed to be pretty decent tomorrow tho, so get out there and do what u can to look. Took me around 2 hrs to remove the header/ downpipe and replace it with the new one. Id suggest seriously keeping your foot off the gas until you fix the issue tho, stay below 10-12lbs to be safe. Your prof says you have a 2g manifold, is that a 2nd gen mani? You have a second gen car so im wondering if its diff.

 

[JCHemenway]

Dang you know what now i cant remember what i have. When i bought the car i think the dude said it was a evo III manifold or a 2g manifold. I should update info and put that i have a 6bolt swap. Ill get my manifold off wednesday because i dont work then. Plus i should have all my new intercooler piping. Hey i just figured id mention that i bought a intercooler piping kit off ebay and also bought a upper IC pipe where the BOV connects to with a Type s Flange and it came with a generic JDM BOV (or so i thought) I just got it in the mail today and my Upper ic pipe with the flange on it sucks but the BOV i was supprised to see a Greddy stamp and ring on the top indicating soft or hard for the spring. The auction shows no Evvidence stating it would be a greddy BOV the picture shows a no name BOV. Should i feel lucky or are these things cheap anyhow. i only paid 40 shipped to my house for both the Pipe and BOV. The name of the auction was actually Ford lincoln mercury BOV kit But i knew it was what i needed

 

[2g awd dsm]

my car did that to me with my old 7 bolt would cut out at 7 psi i thought it was fuel cut then i upgraded to walboro 255 and 550cc injectors with afpr and it still was doin it then found out it was boost leaking like hell!! replaced some vacuum lines and it drove smooth had it on 15psi no problem. then she blew up a month and a half later spun rod bearing......