turbo hesitation

[FrostBite]

Ok, I recently bought my car and it came with a manual boost controller, a boost gauge, and a 3 inch catback exhaust system. I have been playing with my boost controller alot and I cant even get the car to have 10 psi of boost. When I turn it up past 7 or 8 the car starts sputtering when i get up to about 4k RPM. Its sounds like a putt putt and the rpm sorta gets stuck where it is. I thought it was fuel cut but ive heard fuel cut is a more violent problem. So im not sure if its a boost leak or something else. Its puzzling me though because I just want to get up to 10-15psi and I cant get above 10 without this rpm problem. If I have the boost up around 10 or higher, I can get up in the rpms no problem only if i go really slow on the gas pedal. If i try to apply too much pressure to the gas pedal then the problem will happen. Any help will be appreciated, thanks.

 

[GTM]

Originally posted by FrostBite
...
So im not sure if its a boost leak or something else. Its puzzling me though because I just want to get up to 10-15psi and I cant get above 10 without this rpm problem. If I have the boost up around 10 or higher, I can get up in the rpms no problem only if i go really slow on the gas pedal. If i try to apply too much pressure to the gas pedal then the problem will happen. Any help will be appreciated, thanks.

This is sounding very much like spark plugs or wires, have they been replaced and properly gapped?

Cheers,
GTM

 

[turboholic]

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=92632

 

[GTM]

Originally posted by turboholic
http://www.dsmtuners.com/forums/showthread.php?s=&threadid=92632

Whoosh, sorry, not sure I've got a grip on the relationship you were citing. Was your point his last post where he discovered the obvious spark plug breakdown and once that was fixed he could finish diagnosing the other problems?

Cheers,
GTM

 

[FrostBite]

Alright Im going to replace the spark plugs first thing and if thats not it ill get a boost leak test. What are the best spark plugs for talons? On my 240sx I got NGK because I heard they were really good for imports. I hope its the spark plugs since I havnt changed them since I got the car. Thanks for the help GTM and turboholic.

 

[GTM]

Originally posted by FrostBite
Alright Im going to replace the spark plugs first thing and if thats not it ill get a boost leak test. What are the best spark plugs for talons? On my 240sx I got NGK because I heard they were really good for imports. I hope its the spark plugs since I havnt changed them since I got the car. Thanks for the help GTM and turboholic.

Yes NGK, can't remember the number but think it's BPR6ES but for sure check at the store and make sure they are properly gapped.

Cheers,
GTM

 

[FrostBite]

Oh my god, Ive replaced the spark plugs with ngk BPR6ES ones with a 0.28 gap and it revealed my cars actual power. THe spark plugs in their were bosch with a .50 gap and they made my rpms unstable and i couldnt drive fast above 7 psi. Now my rpms are rock stable and i can get up in the 15 psi range without problems. Ive never seen the speed of my car until now. This was a day and night chage. Thanks for the help, now I can start to actually tune my car.

 

[GTM]

Originally posted by FrostBite
Oh my god, Ive replaced the spark plugs with ngk BPR6ES ones with a 0.28 gap and it revealed my cars actual power.
...
7 psi. Now my rpms are rock stable and i can get up in the 15 psi range without problems. Ive never seen the speed of my car until now. This was a day and night chage. Thanks for the help, now I can start to actually tune my car.

Look out you are going to be dangerous This doesn't mean you have to collect speeding tickets or put dents in the body drifting around corners.

I wish they were all that easy. Enjoy!

Cheers,
GTM

 

[FrostBite]

Yeah, I learned my lesson from my last car. I lost control in my 1990 240sx on a windy road at high speeds and flipped it. The car got totaled and it showed me that i wasnt immortal. So now i sometimes drive fast but not as dangerous as I used to.