So previously in my car, I had 60lb injectors, KB BAP, stock fuel system running 91 octane with no issues. So I changed out my pumps to the improved gt pumps, id 1050x, modified FPDM and deleted the PPRV. When I get into boost and then quickly release the throttle, it'll start to violently buck like my motor is being starved of fuel for that brief moment. I keep going back to my tunert o try and resolve this issue and so far after (3) return trips, this still keeps occurring. What could my problem be? Should I be looking get a tune elsewhere?
What would cause my car to buck?
- Thread starter beastmar
- Start date
Have you looked over the datalogs? Are you able to see what the wideband is doing when this happens? Do you still have the BAP?
My first instinct would be the tune. Maybe it's an injector issue. The stuff you changed aren't really big changes.
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My first instinct would be the tune. Maybe it's an injector issue. The stuff you changed aren't really big changes.
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If he hasn’t fixed it in the tune or pointed you in a direction for a mechanical problem, yes, I’d consider a new tuner.
Is it bucking under load and then you’re letting off? It reads like it’s bucking after you let off....
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Is it bucking under load and then you’re letting off? It reads like it’s bucking after you let off....
Sent from my iPhone using svtperformance.com
I have the same issue. I believe its the tune
What everyone else is saying, your new mods need a new tune
Exactly what I thought, no big changes. I still have my bap and my injectors are brand new. I haven’t tried to datalog the issue. What parameters should I be datalogging?
It is not bucking under load. It’s bucking after I get into boost for a quick second and then let off. Once I let off the car bucks.
I have gone to the shop a couple times now to have him fix the tune. Still persists.
Is it a buck or a hesitation?I have a similar issue, that just started lately but i have not done any changes to mine? An mine bucks when i hit it hard from the 2-3 shift? Last tuned over the summer and was running great
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Mine bucks pretty hard, to where i recently been letting off the gas to calm it down, and not embarrass myself from the whiplash effect.
Might check out
http://www.efidynotuning.com/
Under the dashpot write up.
"If while driving during decel conditions you experience 'bucking' then you will need to reduce the dashpot decay rate at that dashpot airmass.
If you do not have enough dashpot present to prevent bucking, it is neccessary to increase the dashpot lbs/min airflow by reducing the RPM in FN882(A).
This is typical with big blocks and higher displacement engines. "
http://www.efidynotuning.com/
Under the dashpot write up.
"If while driving during decel conditions you experience 'bucking' then you will need to reduce the dashpot decay rate at that dashpot airmass.
If you do not have enough dashpot present to prevent bucking, it is neccessary to increase the dashpot lbs/min airflow by reducing the RPM in FN882(A).
This is typical with big blocks and higher displacement engines. "
and you guys have PPRV deletes?
No kinked lines?
My car was doing the same shit, would buck hard on a 2-3 shift, like fuel cut, and i found a kinked line in my PPRV Delete.
No kinked lines?
My car was doing the same shit, would buck hard on a 2-3 shift, like fuel cut, and i found a kinked line in my PPRV Delete.
Thanks for the info! but to reiterate my car was running fine since i last had it tuned in July, just recently a few times out did it start doing this?
Ill have to check for a kink line as well.
My car was getting stupid, spitting and crap. Turned out to be the plugs.
In my case I might try that first, since these cars are a bit finicky when it comes to plugs and the gaps.
I can't have kinked lines in my system after the pprv delete...
I hard line all turn and bends. The only connection that's not hard line is the connection from the hardline to the fitting either on the pump or fuel hat.To run E85
Brand new plugs on my car before I started the tuning process.
I can't have kinked lines in my system after the pprv delete...
To run E85
Brand new plugs on my car before I started the tuning process.
Cant blame you for wanting to be able to run E85
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