Subaru Impreza GC8 & RS Forum & Community banner

1 - 16 of 16 Posts

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #1
im looking at a 2000 rs with an 04-05 sti motor swapped into it. The car will start right up and idle fine, but when i push the gas pedal there is absolutely zero response untill a few seconds after the pedal is on the floor...? Ive never seen a car do this at all and my only guesses are a faulty MAF or possibly the wrong ECU was used in the swap...? Im wondering if anyone has heard of this or has some advice on what it could be...? Thanks
 

·
Registered
11 wrx & 15 fozzy 2.5i
Joined
·
2,000 Posts
Usdm Sti swaps are drive by wire, that means the throtle is electronically controlled and not mechanically like the cable ones, my gf forester xt had some throttle issues and I found that there's a relay that controls the pedal, so your chances are:

That relay is bad.
Something in or The throttle body is bad.
Another sensor that communicates with the throttle body is bad
There's a short in the throttle body system.
Research for voltages values and use a multeter to make sure all that is covered.



Highly doubt is the computer.
 

·
Registered
2000 2.5 RS-T srp sedan
Joined
·
2,731 Posts
Just asking but som 04sti had Drive by wire.


Did they use DBW or Cable for throttle?

Any error codes for the DBW?
 

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #4
where would those sensors for the Tb be..? and the guy says he went through and replaced the fuel pump, throttle body, and gas pedal and its still doing it...?
 

·
Premium Member
2001 A.W. L
Joined
·
13,249 Posts
did this car ever run right? or is this an issue since the swap.

Could be a wiring issue, ecu issue, tune...
 

·
Registered
Turbo, LS swapped Impreza RS
Joined
·
5,172 Posts
Mine had this problem when my coilpacks were plugged in wrong.
 

·
Registered
2000 2.5 RS-T srp sedan
Joined
·
2,731 Posts
If it is DBW, since you haven't answered that yet. Kind of important.

cuz if the pedal is to far etc it messes up the readings and resisstance.
 

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #10
Ahh, yes it is DBW then. The throttle body is supposedly new so shouldnt the dbw system be new as well...?
 

·
Registered
Joined
·
92 Posts
I would do a check on everything snake mentioned in his post. Personally the quickest way to check is to log everything that's going with either ecuexplorer or romraider if you can get them to play nice for you. ..at least those are the two free ways to check that 'most' of the electrical components are reading correctly. Something else to check may be tps voltage which I believe both of those softwares will read.
 

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #12
The car is throwing a P2109-Throttle/Pedal position sens A Minimum Stop Perform....
Maf flow GR/SE-3.69
Abslt tps%-15.6
ST FTRM 1 %-0.0
LT FTRM 1 %-0.0
ST FTRM 3 %- -100.6
LT FTRM 3 %- -100.6 (arrow down)

From this im getting the sensor is obviously bad, but im not sure where the sensor is..? And the Maf is bad and needs replaced. Other than that im not too sure about the rest of the numbers and would appreciate any info on them, and the position of that throttle sensor would also be appreciated. Im also open to other ideas if anyone has any on what to check in addition to these 2 problems. Thanks.
 

·
Registered
GF8
Joined
·
938 Posts
Clear the code and try lightly revving it. Do not floor it. If that works, you need to set the max travel of the pedal for the correct voltage. Also check and see if there is a rubber stop under the pedal. If that's not there, the car will never run at WOT.
It has always been like this since the swap, right?

-Kurt
 

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #14
No, the guy i got it from, got it from a dealer and it ran fine apparently. The story I got was that when the manager of the dealership took it for a test ddrive to lunch one day, it started acting up and then the next day this problem, no revving. So, apparently it ran strong and well at one point. Ill go check for the rubber stopper now.
 

·
Registered
1999 Impreza 2.5RS
Joined
·
25 Posts
Discussion Starter #15
Alright well i looked at both pedals i have that came with the car and im not really sure what "rubber stopper" Kurt was referring too...? And I cant clear the code because I gave back the scanner i had...:(.. Any other ideas or things to check...?
 

·
Registered
11 wrx & 15 fozzy 2.5i
Joined
·
2,000 Posts
have you replaced the Throttle position sensor yet? it's in the gas pedal, on the forester xt there's also a relay that controls the DBW throttle body. just some more ideas.
 
1 - 16 of 16 Posts
Top