Bad throttle body or pedal?
 

I have a vq swapped s13 and finally got it to start up couple of days ago and it runs fine, idles greats but when i depress the pedal for the engine to rev, it doesnt do anything, the engine actually quiets down to where it feels like it stalled but it keeps running. Ive never in my life seen something like this before. But either way, I did do voltage and continuity checks on the harness and everything checks out.

Now i sold my z over 3 years ago so i forgot few things here and there. When i turn ignition on, the throttle body clicks once. If i recall, isnt it supposed to click and then have a low toned whining sound?

Either the throttle body or gas pedal is at fault and i can't see to figure it out... yet.

Thanks

back probe the connector at the gas pedal, signal wire and ground, see if there is a voltage signal while the pedal is depressed. then check the signal being received at the throttle body from the ecm use a hertz setting on your multimeter, its easier to see whats is happening.

Something is really ****ed up because the connector for the trottlebody is not giving me the right readings.

here is the first step of diagnostics.

Attachment 433714

First problem, terminal 1 doesnt have any voltage but instead terminal 4 is putting out almost 5v.

Next, terminal 1 and ground have continuity.

Next, if i disconnect ECM ground wire, theres 12+ voltage running through all of those terminals except for terminal 5 i think it was. Is that supposed to happen? lol

WITH ECM GROUND connected, terminal 4 puts out 5v and the rest act as ground and receive 12+ volts if i send power down the other lead on the multimeter.

I did check the output on the pedal and it is working properly. I just dont understand what in the world is going on.

Ok i just pulled codes and they are

1111 - IVT, forgot to plug it in, should be ok now.

0051 - 02 Sensor. I dont have my right one plugged in at the moment

0223 - Throttle position sensor
An excessively low voltage from the TP sensor 1 is sent to ECM.
Harness or connectors (The TP sensor 1 circuit is open or shorted.)
Electric throttle control actuator (TP sensor 1)

0122 - Throttle position sensor
An excessively low voltage from the TP sensor 2 is sent to ECM.
Harness or connectors (The TP sensor 2 circuit is open or shorted.)
Electric throttle control actuator (TP sensor 2)

2135 - Throttle position sensor circuit range/performance problem
Rationally incorrect voltage is sent to ECM compared with the signals from TP sensor 1 and TP sensor 2.
Harness or connector (The TP sensor 1 and 2 circuit is open or shorted.)
Electric throttle control actuator (TP sensor 1 and 2)

could possibly be a fault in the wiring... sounds like wires have been could have shorted.
check for continuity from the pins at the connector at throttle body, and the connector at the ecm, and verify the continuity is not present between all the wires from throttle to ecm...
eliminate the wires from the equation.
next would be to replace the throttle body...
whats the mileage on the engine.
there could be an internal short, the life span of a throttle body is about 80000 miles give or take, the brushes in the motor seem to wear out.
i am assuming that the harness has not been cut and spliced in-between the ecm and throttle body.

You mean continuity SHOULD be present. I might beleive there could be a short but this wire harness was built by a shop that claimed they tested the harness and it worked fine.

I'm not too sure on the mileage but i dont think it failed due to its age. lol. either way, let me get my hands on a new throttle body and see what happens.

i wanted u to verify that the wires werent shorted to eachother, an easy way to tell this is to check and see if there is continuity between 2 different wires in the same loom eg.. if 12+ wire and signal wire were crossed, there would be continuity between the 2 different pins, on each end of connector.
i also wanted u to check each wire for continuity individually...end to end.

And u never know what happend. something could have been missed, or occured dureing reassembly.
this will help determine if there is a problem on the harness side. and eliminate all possibilities.

another thing to check is that the pin outs are in the correct location, (u mentioned that the terminal 4 had voltage when it wasnt supposed to. and terminal 1, that was supposed to have voltage didnt.)

im going through the same problems your having right now, i did the wiring myself however and i just found out i mixed 2 pins on the throttle pedal up. ill know if i solved my problem in the morning. ill keep you updated on it. i also don't have my o2 sensors hooked up and fear that is whats also causing the problem.

and for what its worth here is a link to my thread.
http://zilvia.net/f/s-chassis/374604...-pic-hevy.html

Did the throttle body fix this issue??

8.75 year dead thread

The same problem on a g35 sedan 2003
 

Did you fix it?

I have the same problem. I have a g35 sedan 2003 and the slip light turns on and after that, the revs just go up until 1400. The engine still on but no accelerate. The check engine light marks p2138. Somebody could help me? I change the throttle body and the mad, but the problem persist

He hasn't logged in for 8 years

Just had this happen to me after changing my valve covers. Disconnect your battery, buy a can of CRC electronic cleaner disconnect everything you can find, spray, let dry and reconnect, if you have dielectric grease use that. You may want to trace wires and check for damage if that doesn't help at all.