Bucking under 2 grand with vortech

Warbird19

Founding Member
Sep 27, 2001
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16
Washington, Federal Way
Well the car works awesome besides a low rpm bucking. Its weird its like the car just stalls at part throttle under 2 grand? any ideas? its really annoying to deal with. the Dyno Tuner said the mass air sensor need to be farther away from the blower. So i moved it about a foot farther away. Any help would be great! thanks Guys
 
stalls like you turned the key off? i know its a long shot but i had a car with a dead spot in the tps that caused a silimalr problem cuz they always had the tps in that range so that part fryed but the rest was ok
 
We need a slogan like "should-a-had-a-v8" only something like shoulda had a chung-o, or shoulda had a jeff... :D

But seriously it does sound like a tuning issue, clocking the maf might help, but if youve already moved it.... I know mine (n/a) bucks at low rpm with too much timing, but that is neither here nor there. (na vs blown)

Call Chung, he might be able to help.

Dave-
:flag: :nice:
 
sounds like a fuel issue, what fuel pump are you running, injector size and fuel pres regulator is your fmu got the correct disc those are the things I would look into. also about your maf you can change the rotation of the maf and that will change the tune I would start with the maf level. I had some of the same issues at first so I hope this helps
 
the car has a C&L 80mm mass air, 42# injectors, AFPR, 255lph Walbro intake. The car runs like a champ when driving above 2 grand. Also below 2 grand when i open the throttle up more it works fine! Sucks cause when im trying to start out in first i have to rev the thing pretty good to get going. If its below 2 grand the thing fall all over itself and pops and crap. Im wondering if its too low on fuel or somthing. The car has been tuned by blood enterpise. I really want to take it to chung but thats a hell of a drive. Also Blood burnt me a custom chip for the car and they have a mustang dyno. So i dont know what im going to do. thanks for the help. Anything else?
 
my car used to buck under 2 grand aswell but i think it was when i had 2.73 gears switched to 3.73 and no longer have the problem. i noticed you have lower gears (3.73's) so i guess it is a tuning issue with you. maybe your cam doesn't like under 2 grand?
 
I dont diagnose cars online, WAY to many variables. No to mention the "cooks in the kitchen" thing. But one thing that hasnt been brought up yet is: Did it just start acting up or has it been that way since the tune was done? You will be looking for different things depending on if it has always done this or not.
 
I have just installed an vortech on my '91 GT and have a similiar problem. It is easy to stall just off idle and is difficult to start. Had Chung look at it and he slightly leaned the mixture at idle which has helped. He just burned a chip for it so it was easy for him to make this change. You might have him look at it, he can probably help.
 
Does the car have a EGR valve still on it? Try capping it if it does. See if your bucking stops. I know my car is the newer ECC version, but when I swapped in my 4V into a 2K gt I got bucking at around 2K RPM, car ran fine otherwise. I capped my EGR and the bucking went away. Could be a O2 sensor as well, hard to dignose online.
Scott