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So had to take off the tb elbow to get to the secondarys and was surprised to see a butterfly missing.. the one that's there has a bolt missing and the other stripped to ****.
Not sure what whoever did this was attempting?? but I am trying to diagnose my random bucking which seems to come after car hasn't run for a few days or longer could this have somthing to do with it???
Car is a s5 na vert.
unlikely it is the cause, those butterflies are open 99.999% of the time.
seems someone was attempting the classic T/B hack mod and failed miserably and gave up. hopefully they fell on a knife, since i see nothing on that engine that warrants such a mod and just another **** who had to follow the masses of ******* lemmings in doing that ****.
bucking is a lean condition, could be clogged filter/strainer, low pump voltage, low fuel pressure, clogged injectors, vacuum leaks, bad harness wiring or bad injector ground on the engine block. generally it is a bad ground connection on the main engine harness to the rear rotor housing or low voltage to the fuel pump, less likely is a botched fuel pump installation. i wouldn't rule out numerous vacuum leaks causing a lean condition either, cold plastic contracts and causes the seals to leak more until fully warmed up and most of these engines have 20 years of abuse and almost all have vacuum leaks of varying degree, ironically i see people swear up and down they have no intake leaks but i pressurize the system to even 1 PSI and it looks like a bubble factory all over the intake system.
Last edited by RotaryEvolution; Sep 12, 2015 at 01:55 PM.
unlikely it is the cause, those butterflies are open 99.999% of the time.
seems someone was attempting the classic T/B hack mod and failed miserably and gave up.
bucking is a lean condition, could be clogged filter/strainer, low pump voltage, low fuel pressure, clogged injectors, vacuum leaks, bad harness wiring or bad injector ground on the engine block. generally it is a bad ground connection on the main engine harness to the rear rotor housing or low voltage to the fuel pump, less likely is a botched fuel pump installation. i wouldn't rule out numerous vacuum leaks causing a lean condition either, cold plastic contracts and causes the seals to leak more until fully warmed up and most of these engines have 20 years of abuse and almost all have vacuum leaks of varying degree, ironically i see people swear up and down they have no intake leaks but i pressurize the system to even 1 PSI and it looks like a bubble factory all over the intake system.
That's what I was thinking^ car is completely stock so wtf lol they only close on cold starts I thought..
I honestly have not really checked for vaccum leaks...May just replace all vacuum lines when I pull intake to do the main ground.
I do have a fuel pump I'm going to put in this weekend along with the infamous heater hose that busted and pegged the gauge ffs....still starts right up tho so I got lucky I guess.
Its odd tho because it's only after I let the car sit for a few days....if I daily drive it everyday I never feel the bucking.
Last edited by invinciblejets; Sep 12, 2015 at 02:04 PM.
