help: weird pull problem

[onze07]

so i just bought a cobb ap and installed the stage 2+ 93 fmic map and the cars feels great now but something weird keeps happening. when i get around 6000 rpm the car jerks back twice and i dont know whats causing it. it may be something with the ecu like cutting the power or something idk but can anyone help who knows what im talking about? could it also have to do with the blow off valve?

mods:
cpe cai
cpe fmic
turbo back exhaust
turbosmart blow off valve
cobb ap

 

[SallySpeed3]

Could be a number of things. My guess is boost cut cause your fuel pump can't handle all the mods.

 

[oaklandopen]

Its cold out, could be cut due to temp

 

[spdjnke]

sounds to me like spark blow out. check your plug gap.

 

[MSMS3]

sounds to me like spark blow out. check your plug gap.

When I got spark blow out it was at high boost but lower rpm - around 4,000 to 4,500 rpm. True, it happens when the plug electrodes wear and the gap opens up. OP should check the gap and narrow them back to .030. That might solve the problem. But, I'm thinking that with the higher rpm cut he is running into true load cut due to the cold weather and the load tables on his AP tune. He's in New Jersey.

 

[SallySpeed3]

where in new jersey are you from?

 

[Jasnall]

I blew a hole in one of my BOV vaccum hoses getting on the freeway once. Felt like somone had hooked a bungee cord to my car. Check for boost leaks.

 

[onze07]

thanks guys and in north jersey, i will try your recommendations

 

[oaklandopen]

Other thing is did it only start happening AFTER you did the AP? Try to pinpoint when it started and it. Would be easier to diagnose

If that's the case then uninstall and see if it still does it

Although, with your tbe, you could be getting boost spike from a freer flowing dp

 

[onze07]

problem does not happen with stock map, so maybe the ap is creating too much pressure and my blow off valve may be adjusted improperly?

 

[spdjnke]

Wait a minute, are you running VTA or in recirc? if you don't have that issue with stock map, then more then likely its the map that your running.

 

[MSMS3]

Wait a minute, are you running VTA or in recirc? if you don't have that issue with stock map, then more then likely its the map that your running.

Probably true. But depending on the map, if it is upping boost with that map, then he may be experiencing load cut, or may be experiencing "spark blow out" from the higher boost. On the stock tune with lower boost, he might not hit load cut and might not have enough boost to interfere with spark delivery across the electrodes of the plugs.

But you are probably right that a better map may be the answer. I'd look at those plugs too, though.

 

[onze07]

Spark plugs seemed normal, im gonna go to a tuner soon to try and fix this