SAFC 2 Problem

[In-Serenity]

Hey, earlier today i was messing around with the wires for my O2 sensor and i messed soemthing up. Now my idle is weird and my throttle on the AFC reads 100% for no reason. Also when i hit the gas slowly, the car sputters to 4k rpm. If i hit the gas faster, the engine sounds more normal. At idle, the engine is sputtering. Im thinking that the fuel is being dumped into the cylinders as if the throttle was at 100% but there isnt enough air because the pedal hasnt been touched (at idle).

Any suggestions on what to do? Anything at all?

 

[gringoloco]

I really dont think you messed something up messing with your wires, at the most the o2 sensor maybe. To me it sounds like your throttle body plate or throttle cable is stuck wide open. I believe the 2g have a throttle sensor also so check that out also. but def. I think the problem is located in the throttle body area, or the ISC motor.

 

[In-Serenity]

how would i go about fixing this?

 

[tlcoll1]

Originally posted by In-Serenity
Hey, earlier today i was messing around with the wires for my O2 sensor and i messed soemthing up. Now my idle is weird and my throttle on the AFC reads 100% for no reason. Also when i hit the gas slowly, the car sputters to 4k rpm. If i hit the gas faster, the engine sounds more normal. At idle, the engine is sputtering.

Mebbe the throttle input to the AFC is shorted? Or if it isn't, perhaps the AFC has hosed up its perception of what 100% idle is - isn't there a way to reset this value? If you have a voltmeter, hook it up to the TPS line at the AFC, turn the car on to ignition but don't start it, and see what voltages you see. Should be < 1 volt with your foot off of the gas, or > 4 volts with it floored.

Tom

 

[In-Serenity]

When i did the sensor check in the ETC part of the menu on the AFC, the voltage was 5.??? and when i floored it there was a slight change, but was still above 5. When i remove the wire that goes to t he tps, it drops to 0.015 or so

 

[In-Serenity]

I just checked the voltage of the wires that plug into the TPS and i believe 3 out of the 4 of them had a reading above 4 and 5....how do i reset this?

 

[tlcoll1]

Originally posted by In-Serenity
I just checked the voltage of the wires that plug into the TPS and i believe 3 out of the 4 of them had a reading above 4 and 5....how do i reset this?

Very strange. Sounds like either the TPS is bad, or you have a short. According to the manual, you check the TPS by disconnecting the connector from it, and measuring resistance between the pins. Pins are 1234 (facing it, with the tab upward). Pins 1-4 should be ~5k, pins 2-4 should be variable between 0 and ~5k, depending on the throttle opening, and 3-4 should be 0 ohms when the throttle is closed, or lots ohms when it's open.

If you have a short, I'd try disconnecting the TPS wire that goes to the AFC first, and re-do your voltage measurements.

This sounds a lot like it must be your problem.

Tom

 

[In-Serenity]

I just checked the resistance in the pins

1-4 = 4.61k

2-4 = 4.63k

3-4 = 4.05k

 

[In-Serenity]

Alright, so based on the information given, the resistance between Pins 3-4 is messed up. Now, do u think this is a reason for why my car sounds like a lawn mower when its on? Also, could it be a reason for why when I hit the gas, the RPMs climb slowly (probably takes 5 seconds to reach redline) and it sputters the whole way (just like it does when at idle)?

 

[In-Serenity]

Thanks Tom, Im pretty sure the TPS is what the problem is. I just want to make sure though, are 100% certain that Pins 3-4 resistance should be 0 at closed throttle? I just want to make sure. On my TPS (which i think is broken based on the info) at closed throttle is 4.XX k, and at WOT it drops to 0.05k. Just making sure before I go out and buy another TPS. Thanks

 

[tlcoll1]

Originally posted by In-Serenity
Thanks Tom, Im pretty sure the TPS is what the problem is. I just want to make sure though, are 100% certain that Pins 3-4 resistance should be 0 at closed throttle? I just want to make sure. On my TPS (which i think is broken based on the info) at closed throttle is 4.XX k, and at WOT it drops to 0.05k. Just making sure before I go out and buy another TPS. Thanks

That was what the manual I have for the car said, but if you got what you got then that must be wrong. From what you said, then, it sounds like the TPS is ok - if the resistance varied linearly as you hit the throttle, it should be ok. In that case, look for a short circuit - the varying resistance in the TPS "tap" is what causes a varying voltage to the ECU. You're getting no real variation in your TPS voltage, at last as measured by the AFC.

Tom

 

[In-Serenity]

WTF..ok so i replaced my TPS with another one (from a working 2g turbo), on that ones the resistance on Pins 3-4 were pretty much the same (high 4s). BUT my throttle is STILL stuck at 100% on the AFC. Im thinking of just clipping the wire that goes from the TPS to the AFC so it doesnt dump fuel into the cylinders. What should i do now? Thanks.

 

[tlcoll1]

Originally posted by In-Serenity
WTF..ok so i replaced my TPS with another one (from a working 2g turbo), on that ones the resistance on Pins 3-4 were pretty much the same (high 4s). BUT my throttle is STILL stuck at 100% on the AFC. Im thinking of just clipping the wire that goes from the TPS to the AFC so it doesnt dump fuel into the cylinders. What should i do now? Thanks.

Dunno what else to suggest. It's got to be a wiring short. Clipping the AFC TPS wire is certainly a good start, but also double-check the rest of the wiring and re-measure the TPS voltage to the stock ECU (or on the clipped wire, or on the sensor) as you check things.

Also, the short must be to 5 volts, not to ground, since the AFC reads a high TPS value all of the time.

Tom

 

[ceschwede]

I had this same problem on a 2G Turbo, and i found that I had a bad ground somewhere (still do not know where), but i spliced into my ground wire on the TPS and ran my own ground, worked like a champ. The other sensors that share that ground were also at 100% as well, such as the air temp sensor in the MAF (-40deg) and the Coolant Temp sensor(-40deg). Just something quick to try. GL