Hey guys, I've been daily driving my FD with no time to work on it for the passed 6 months and it started to get the 3k RPM hesitation. Not long after it would be driving fine and then all of a sudden just fall on its face. So I haven't been driving it for about 4 weeks and I made this video to help you guys figure out my problem.

I'm thinking it's a fuel issue because my wideband will read lean when it starts bucking and acting up. Supra fuel pump is about 3 years old, fuel filter is 2 years old, stock primaries have most likely never been cleaned and the 1600 secondaries are about 3 years old as well. The 3k RPM hesitation make me think maybe something is wrong with the wiring to my fuel pump?

Heres the video

http://www.youtube.com/watch?v=DmhdH...el_video_title

 

Check the connections at the pump itself. Also check the fp relay.

Also check the tps.

 

real easy to check your fuel pump voltage. remove your carpet to access your pump. you will see a white plug. the red and white wire (the heaviest guage) is the power to the pump. either connect a ohm meter directly to it or run a wire to the front so that you can monitor the voltage while you drive. easier if you have an assitant.

and as iqwik7 suggested check VAT1 and VAT2 on your commander. do this first as it is much easier.

 

Could also be your secondaries not coming on.

I have worked on an FD that bucked super bad, it had a rusty gas tank and clogged fuel filter.

Dale

 

looks to be a dieing fuel pump, i would check your voltage and actually remove the pump run power to it and see if it sounds weak, if the voltage is in check. if fuel pump sounds weak replace and start enjoying or FD again.

 

i should of told you before when we talked, it could of been the injector i remeber one of mine went out and wouldnt let me go over either 3k or 4k, just fell flat.. you should be able to put ur old Ecu in it and do a code test to see if it shows.

 

So when the car starts bucking the VTA1 readings drop low, but eventually it will come back and run okay again. I haven't adjusted the TPS at all. Does it sound like I just need to adjust the TPS or do i need a new one? Could something else be causing the VTA1 voltage to drop? It drops to ~.25V

 

+1 I agree it may be the fuel pump starting to go.

 

Did you rewire the fuel pump? you may be overheating the stock fuel pump wiring.

 

Thankyou for uploading a video!!!

Check TPS
http://robrobinette.com/tps_adj.htm

Definetly check the fuel pump and if you haven't changed the fuel filter in a while do that too. Those supra pumps draw a decent amount of amps and you might have cooked your wiring if you didn't rewire it.

Also, double check your grounds. I've had a bad ground give me similar (but not nearly as severe) problems.

 

+1 fuel pump re-wire
+1 on tps adjustment, also, check that vta1 and vta2 are within FSM specs at no throttle and at wide open throttle.
+1 on checking voltage at fuel pump

also, surprised this wasn't mentioned already, check the fuel pressure... (that'll help determine clogged filter, bad pump)

if all those seem ok, could be related to ignition? but I'd assume, bag ignition would make the wideband read rich not lean.