Help! What causes car to buck in 3rd when boost comes up?

scrappin

New Member
Apr 28, 2010
6
0
0
Donalsonville, GA
Excuse my ignorance with this question but my car (92 Turbo Supra with 121k) has been running great to this point (about 800 miles since purchase). Here is what is happening: As I accelerate and shift into third gear when I see the boost gauge coming up, the car will buck real hard one time, the check engine light will come on but if I get out of it the light goes off and car appears to run fine. It only does this so far when I really try to bring the boost up in third gear. I have checked vacuum hoses, tightened the silicone hoses for the intake, turbo etc but am about to lose my mind with this thing. Any suggestions?? Any advice will be greatly appreciated!!
 

Kevin

7mgte -> 7mgte swap done.
Apr 20, 2009
865
0
0
Windsor Ontario Canada
is it all stock|? because if you are running stock piping, then you need to check for crack... literally remove the piping and squeeze them, etc.. sounds
have you checked for codes? (your check engine light does not need to be on to have stored codes)
 

89supraa

New Member
Jul 20, 2009
77
0
0
milwaukee
This was happining to me when I had a boost leak. Make yourself a tester and find it. The bucking is fuel cut, that is why the check engine light is coming on. There are a couple how-to's on this forum on making a tester. Hope this helps, Good luck!
 

scrappin

New Member
Apr 28, 2010
6
0
0
Donalsonville, GA
No the piping is that silicone stuff by Spectre. It has a HKS intake on it. I called myself making sure that all of the clamps were on the piping correctly and not leaking but everything looks good to me...Obviously I have missed something. I thank you for the reply, I will tackle this thing again tomorrow.

---------- Post added at 09:00 PM ---------- Previous post was at 08:58 PM ----------

kamikazemkiii;1585970 said:
do you have a boost controller? how many psi do you usually boost?

No, I don't have a boost controller. The gauge shows 8 lbs of boost
 

Dirgle

Conjurer of Boost
Mar 30, 2005
1,632
0
36
42
Pauma Valley, CA
scrappin;1585985 said:
Thanks again, I will have to take it to someone because I can't "pull the codes".....

Like stated above, if you have access to a paper clip and have the ability to count you can pull the codes. These are pre OBD-II cars and do not require fancy computers to do such things, thank god.