Occasional Bucking and stuttering at low rpms

[jorge4g63]

Hey people, just a quick question.
My car recently started only occasionally sputtering when i give it gas at low rpms, meaning that it sputters or stutters as i begin to give it gas and builds boost, as soon as it clears the car just thrusts forward and neatly accelerates.
I run magnacore wires with BPR7ES-11 plugs gapped at 28, i just installed them sunday because i thought it could have been my old plugs fouled, BTW my old plugs were BPR7ES
without the 11 designation at the end.

Has anybody experienced this? Can anybody help?

Any input will be greatly appreaciated, thanks in advance.

 

[CrazyM]

Sounds like you could use some new plug wires Worked for me when I had the same (sounding) situation!

 

[dragnby]

is it like some one is holding the car back or it jumps forward a little at a time then takes off? or does it cut out like no spark?

 

[jorge4g63]

It sounds just like the first situation you described dragnby, it's like it's being held back (too much fuel) and suddenly launches forward really fast. Any thoughts on this?
WTF

 

[Clutch GSX]

Well your car profile isnt really filled out so I dont know exactly what to tell you but here's my advice:

Check spark plug gaps again
Check for boost leaks!
Make sure your AFC or whatever youre using to tune is working correctly
Check your injectors for clogs
Make sure youre not running too much boost for your injectors (check boost controller if you have one to make sure it is set right)
Test to see if your spark plugs are getting sparks

If everything looks fine report back and we'll have to figure something else out.

 

[jorge4g63]

Hey Clutch GSX, thanks for replying. The reason my profile isn't filled out is because i haven't yet installed the parts i purchased, so my car is at stock boost with no performance parts installed besides a full 3inch turboback exhaust.
My plugs are gapped at 28, but i will check how to make a boost leak tester as i haven't checked for those.
Any other ideas????

Thanks a lot peeps

 

[jorge4g63]

Just a quick update my friends, here's a list of things i checked or changed regarding my sputtering problem:

Coilpack
New plugs
Checked all intercooler hoses and all are good
Checked MAF

The car still sputters occasionally when trying to accelerate, it feels really held back sputtering and suddenly it clears up and accelerate violently.

DOES ANYBODY HAVE ANY INPUT? ANYBODY WITH EXPERIENCE, WISEMEN PLEASE HELP

 

[Mr2god]

Sounds like a boost leak. Do a boost leak test before you start spending money on stuff that is probably fine. I was having the same problem, intermittent stuttering at low rpms when I tried to accelerate. I had a nasty boost leak at my throttle body shaft seals and just fixed it this week and no more stutter, period.

 

[jorge4g63]

Sounds exactly what i'm going thru mr2god, guess i'll have to do that boost leak. Do you have any idea where i can get info on how to make a tester?

And thanks again bro

Any other advice??????

 

[1slo1g]

Sounds exactly what i'm going thru mr2god, guess i'll have to do that boost leak. Do you have any idea where i can get info on how to make a tester?

And thanks again bro

Any other advice??????

If using a compressor, turn the pressure down to about 20psi. Easy to make for anyone that knows which end of a screwdriver to drill holes with:

http://www.vfaq.com/mods/ICtester.html

Stealth 316 - Intake pressure tester

 

[Mr2god]

If using a compressor, turn the pressure down to about 20psi. Easy to make for anyone that knows which end of a screwdriver to drill holes with:

http://www.vfaq.com/mods/ICtester.html

Stealth 316 - Intake pressure tester

Yep thats what ya need. Just hook it up and hold charge it up to 20psi or so and see if it can hold it. Soapy water helps to find your leaks, but most will be pretty obvious(a loud hissing sound usually). It helps if you have two people so one can keep an eye on your boost gauge. You don't want to accidentally charge it up to like 40psi and blow out a gasket. But I'm sure you have a regulator on your air compressor so it shouldn't be to much of a problem. Good luck

 

[jorge4g63]

Hey gang:
I made my boost leak tester according to the vfaq, and i regulated my air compressor to 20 psi. Still when i introduced air in my system i hear nothing and the soapy water reveals nothing, am i doing this right?????

Should i open the throttle when i do the leak test? I'm really stumped and angry because i want to get my car on the road driveable already. Please somebody with experience chime in and point me in the right direction.

Thanks in advance people

 

[Raptoreborn]

Hey gang:
I made my boost leak tester according to the vfaq, and i regulated my air compressor to 20 psi. Still when i introduced air in my system i hear nothing and the soapy water reveals nothing, am i doing this right?????

Should i open the throttle when i do the leak test? I'm really stumped and angry because i want to get my car on the road driveable already. Please somebody with experience chime in and point me in the right direction.

Thanks in advance people

No, don't open the throttle. Listen cloesly to any loud or low air (hissing sound) coming from throttle body, BOV, vacuum lines, IC and IC piping. It's a lot easier to have a second set of ears. If it is a small boost leak, it is hard to see and hear pin size leaks.

 

[jorge4g63]

Hey raptoreborn, thanks for clearing that up for me. I am in the process of hooking the boost gauge and test again. I'll get back with results hopefully this evening.

 

[Clutch GSX]

If its a pin sized hole its not going to produce the symptoms that you described. It should be fairly obvious. If you dont find anything try one of the other suggestions. maybe your boost controller isnt working. Also if you have a BOV then you should recirculate it or put it back to stock.

 

[jorge4g63]

Hey clutch gsx, thanks for replying. Can the stock boost controller fail to that point where it produces said symptoms????
Keep in mind my car is stock, i have a lot of parts waiting to be installed but none of them are. I'm currently installing my boost gauge to check again but that is about the only mod done, oh and the turbo back exhaust. Even the boost is at a stock level.

I already recirculated the BOV just a couple of days ago and to be honest the car improved a whole lot but still stuttered sometime like at around 2500 to 3000 rpms. And sometimes the idle goes to 500 rpms but the car doesn't die or nothin.

Any idea what that could be?????

Thanks again

 

[Clutch GSX]

Hey clutch gsx, thanks for replying. Can the stock boost controller fail to that point where it produces said symptoms????
Keep in mind my car is stock, i have a lot of parts waiting to be installed but none of them are. I'm currently installing my boost gauge to check again but that is about the only mod done, oh and the turbo back exhaust. Even the boost is at a stock level.

I already recirculated the BOV just a couple of days ago and to be honest the car improved a whole lot but still stuttered sometime like at around 2500 to 3000 rpms. And sometimes the idle goes to 500 rpms but the car doesn't die or nothin.

Any idea what that could be?????

Thanks again

If your boost controller is broken it can cause all sorts of problems like that. Why do you have a boost controller if you are still running stock boost? Put it back to stock and see if that solves the problem. Id borrow someone elses boost contorller or order a new one to make sure that isnt the problem. Check your compression and all the bolts throughout the pressurized system. Check for vaccum leaks as well as boost leaks. Get a logger asap. You should not have any aftermarket mods except maybe exhaust if you dont have the proper equiptment to manage and tune your car.

 

[jorge4g63]

Merry christmas everybody
As i stated in my other post i do not have any aftermarket mods in my car except the exhaust, i don't even have a boost controller,

And another question, how do i check for vacuum leaks? Anybody care to chime in on that one???
Thanks for all the help people