car will bucking and misfire

[mitsumissile]

I have a 97 GST. My car has some problem. The problem is at idle when I press the gas pedal first time, it's ok. The rpm will go up normal. As soon as I let off the gas and press the second time, the car will bucking and misfire. The rpm will hold and go up. While I am driving, when I change gear and press the gas pedal again, the car will shake. I have the wideband AF. I notice when the problem happened, the AF is like 17. It looks like lean at that time.
I already swap:
coil pack
power transistor
camshaft position sensor
TPS sensor
ECU
Fuel pump
FPR
from my friend's car and I also change the:
Spark plugs
Spark plug wires
CAS



It still has the problem. I also got no cel.
Can someone tell me how to do next? Thanks
Here is a video clip.

<embed src="http://videos.streetfire.net/vidiac.swf?video=4d6b6ffe-2096-401e-8de9-9c0500dfea5c" width="428" height="352" allowFullScreen="true" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer"></embed><br/><a href="http://videos.streetfire.net/video/Wired-problem_681340.htm?ref=41505132-d345-48b1-8fe5-9b5d00117d8d">Wired+problem</a>

 

[Lost_sol]

i cant get the vid to work for me

 

[habitatguy187]

I would suspect the fuel pump and wiring. Sounds like it's dying out when you let off the throttle (alternator isn't pumping out as much power) I would start with a fuel pump re-wire, and if that doesn't do it I'd change my fuel pump.

Again not positive that this is the fix, but it definitely could be.

 

[stevo911]

Check the timing on the CAS

 

[mitsumissile]

I would suspect the fuel pump and wiring. Sounds like it's dying out when you let off the throttle (alternator isn't pumping out as much power) I would start with a fuel pump re-wire, and if that doesn't do it I'd change my fuel pump.

Again not positive that this is the fix, but it definitely could be.

I already swap another fuel pump in my car. It still did the same thing. Thanks

 

[mitsumissile]

Check the timing on the CAS

I will try that. Thanks

 

[viperbenz1]

hey my car keeps back firing at 6k, i dont have a boost contoller and im runing 15psi on a 14b do you have any idea what could it be?
you think vacum lines are wrong or something?

 

[habitatguy187]

I already swap another fuel pump in my car. It still did the same thing. Thanks

Did you re-wire the fuel pump? If not it's a lot easier than it looks. 2G DSM FWD Fuel Pump Rewire Instructions

It's almost like the fuel pump isn't getting enough voltage to it. Also what are your spark plugs gapped at? (probably not the problem but who knows )

 

[stevo911]

Did you get to check CAS?

 

[mitsumissile]

Did you get to check CAS?

Yes, I did. I swap it to a new CAS.

 

[4cyls_of_fury]

when was the last time you changed your fuel filter?