shawn21389

Hey guys bear with me on this cause this is my second time posting here but I really need help, I have a 2010 LNF and it just started to give me some issues, while driving I can hear the BPV constantly letting off boost and the car bucks and jerks around something fierce! It's un driveable! I put a aftermarket BPV in hoping that would work but it did nothing, I also changed the BPV solenoid that all the lines are connected to and still nothing, I disconnected the battery for a while and still no change! No check engine light or nothing, it completely bolted with a ZZP PCM, I put the stock PCM thinking maybe something with the tune but same result! Any ideas wtf is going on? It's my daily so I need it for work, thanks for your time and patience.

Sl0wbaltSS

Are you driving 80mph? Do you have it hooked up directly to the manifold? That's why it does it. Drive slower and it will go away.

shawn21389

no unfortunately it does it every gear even at low speed, I mean in first gear it jerks so hard I can't even drive it, it's almost worse at lower rpm's, I never changed anything, it just stared to happen a coupe days ago for no apparent reason

shawn21389

It does it at any speed and any gear, seems almost worse at lower rpm, 1st gear jerks so hard it's unbearable

KMO43

Try a boost leak test. If you have a leak post maf it'll throw the trims way off and can cause bad driving issues. Do you have a stock intercooler?

Snail_SS

iTrader: (3)

What "aftermarket" bpv did you put

shawn21389

no ZZP

shawn21389

I think the company is Forged

shawn21389

I should correct that when I say the BPV is constantly letting off boost it still has a very quick moment that it lets a tiny bit of boost build for maybe a second, not even enough to register the boost on the RPD, but then instantly lets it off and I can hear the BPV slightly whistle, Thanks again for your guys time!

ForceFedDork

your description is too vague.
Describe more precisely what the car is doing, what gear, rpm, throttle position, manifold pressure (if you have a gauge) i'd ask for a data log if you have the means.

describe your setup, all mods, how are your vacuum lines routed, i've seen some odd stuff with routing on this site.

if the car was not stock when you bought it, you might as well take a picture of how all the vacuum tubes are routed, just to establish a baseline here.

Then we can start talking.

Keep running your stock ECU, then read codes, EVEN with no check engine light, read codes, not all codes set the check engine light. I say keep the stock ECU because you dont know which codes were changed or turned off in the aftermarket tune.

T-fog

^^^This and Also take picture of you bpv you could have ordered wrong like me and got a BOV lol

Also is this new or used? Is all the rubber o rings/seals there? If it is used did you lube the piston?

shawn21389

Forgive me this is my second time every using a from, So the car is a 2010 Cobalt SS. It has roughly 27,000 miles on it and I have owned it since it was new. It currently has ZZP upper and lower charge pipes and a ZZP intercooler and ZZP catless down pipe and KN intake. It had the ZZP tune on it at the time but I just put the stock computer back in to try to fix my problem. What that being said I'm no mechanic here and my knowledge with cars is kinda basic so bear with me. My issue is when I drive the car it feels like it violently misfires and it makes the car jerk. I can also hear the BPV whistling off boost, but this is all at less then half throttle, at wot it's just fine with no issues at all, at low rpm and every gear it's like someone is stepping on my gas pedal as hard and as fast and they can repeatedly as the rpms climb it almost goes away. I'm thinking 2 things but I could be way off! Maybe the throttle body sensor or my lower map sensor, I say the map because the dealer who installed the gm stage 1 kit just used butt connectors for the wiring, I had that installed when I first got the car so once again nothing new, but every since it was installed once in a blue moon the car would act up but a little and not produce any boost or it would jerk a little but no where near as bad as now. When that would happen I would just move the lower map wires with my fingers and just the slightest movement would stop the issue. Getting them soldered is on my list don't worry. But I tried moving the wires multiple times and nothing has worked. I have no way to data log anything and will have to find a scanner to see if there are codes. I know I'm not much help sry

shawn21389

I had the stock one in at the time the problem started, I switched to the forged one which is the same as stock one it does not vent to air I'm 100% sure it's the correct one, but that still didn't change the issue so I don't think it's the BPV itself

LNFwagonSS

There are pending codes most likely. Find them with a good quality scan tool.

ForceFedDork

Most obvious first step, LIKE YOU SAID, please fix those MAP wires, and do it right. If you're not mechanically inclined, not used to soldering in an automotive environment, find someone to help. Hell, post your location on here, someone might be willing to help, if ur somewhere around detroit i'll log ur car and solder them right.

Although it never happened to me i have seen some threads where the MAP sensor itself fails, that might also be your problem. (although that's just a guess).

It could be a LOT of things, i'd rather not just start guessing, the list is too long. Autozone/Advanced auto/Oreiley's will read codes for you for free, write down the codes they read out, ignore their recommendations, and come post the codes here.

Your details helped, thanks for that. First things first, fix the wiring on BOTH those MAP sensors, and we'll go from there. The parts list you stated seems like quality parts, i'm surprised you dont have codes, at least the cat performance code or something.

shawn21389

Ok I will start with the map sensor wiring and go from there but it will take me some time cause I'm in the process of moving and that was my DD, I'll have it towed to a dealer so they can properly fix the wires and look up the codes when I get some free time. Unfortunately I'm not close to you to log the car but I really appreciate your offer. Thanks again for you guys helping me out

tomj77

iTrader: (2)

most likely ur bpv solenoid died or ur vac tank is blown, bypass them to see

shawn21389

I replaced the solenoid so I know it's not that and the tank delete has been done for a while now. I did mess with those map wires even more though and stretched them out, and took the car for a spin and it ran perfect, not one issue! So it has to be the shitty wiring job, I'm just gonna get it fixed and go from there but I'm 99.9% sure that's the issue.

tomj77

iTrader: (2)

probably right