I am completely lost on this one...

No matter how I have the sensor wired I end up getting 1.5V (26%) shown by Hondata. I even disconnected the sensor and I have 1.5Vs...WTF?

I tested the sensor with an OHM meter and it seems to be doing its job (Ohms goes up and down when I turn it).

This is a 91 CRX DX with a MPFI harness converted for the B18C swap. I havn't touched the TPS wires, and I am using a Boomslang conversion harness.

Any ideas?

 

At least it looks good...

 

Perhaps I'm way off of what you're getting at... but: honda TPS relate the actual throttle-plate position by a change in voltage. You stated that with a multimeter, you're able to watch the resistance change with the throttle position. A honda ecu doesn't look for a change in resistance (at least for TPS anyway)... it looks for a change in voltage.

Can you see the voltage change with a multimeter when you change the throttle position?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">Perhaps I'm way off of what you're getting at... but: honda TPS relate the actual throttle-plate position by a change in voltage. You stated that with a multimeter, you're able to watch the resistance change with the throttle position. A honda ecu doesn't look for a change in resistance (at least for TPS anyway)... it looks for a change in voltage.

Can you see the voltage change with a multimeter when you change the throttle position?</TD></TR></TABLE>

Thats actually what I meant...The multimeter was reading voltage, and it did show a change as I turned the sensor. I just said OHMs because I refer to the tester as an OHM meter

It definetly has to be something with the harness wiring, mainly because I still had 1.5Vs even with the sensor unpluged! However, I'm still kinda unsure because I never touched the TPS wiring on the harness.

I'm going to trace the harness tommarow and see if the wires are going to the correct locations at the ECU.

Did you guys ever find what was up with your car?

 

Word from the wise, I noticed this same thing when we put my new motor in. Went to set it nothing. Found out the freakin car has to be running to set this. Fixed once we found this out.

Try it. I haven't read all your posts in this thread so I apologize if this was mentioned.

Brad

 

I had the same thing happen to me, turn the key to the on position, and don't even worry about the hondata output, if you try to adjust it by viewing the hondata logs, the ecu will throw a CEL if voltage goes negative, so it will default to 26%. so use the multimeter to set the TPS sensor, then bolt it down and see if the CEL appears again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote">I had the same thing happen to me, turn the key to the on position, and don't even worry about the hondata output, if you try to adjust it by viewing the hondata logs, the ecu will throw a CEL if voltage goes negative, so it will default to 26%. so use the multimeter to set the TPS sensor, then bolt it down and see if the CEL appears again.</TD></TR></TABLE>

I used the hondata HOndalogger to set it with no problem.

 

With the sensor unplugged, you're saying you get 1.5v on the input line back to the ECU (using the ground that is in the connector)?

And if you plugged the connector back into the TPS, you still get 1.5v?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">With the sensor unplugged, you're saying you get 1.5v on the input line back to the ECU (using the ground that is in the connector)?

And if you plugged the connector back into the TPS, you still get 1.5v?</TD></TR></TABLE>

With the sensor unplugged, I still had 1.5V.

I checked the wiring today and both the constant 5V and signal return are wired correctly to the ECU.

I will try to set it with the car running just like you said Ladysman...but the hard part is getting it to run long enough to set it.

 

I know this sounds crazy and I'm not saying you did it, but I have seen people get the TPS and MAP connectors crossed up, since they're the same plug... Something to check, though...

 

Its a GM plug...so thats not da problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote">I had the same thing happen to me, turn the key to the on position, and don't even worry about the hondata output, if you try to adjust it by viewing the hondata logs, the ecu will throw a CEL if voltage goes negative, so it will default to 26%. so use the multimeter to set the TPS sensor, then bolt it down and see if the CEL appears again.</TD></TR></TABLE>

its kinda weird...but I'm not getting any CELs or Error codes.

 

that's strange, cause 1.5v/26% is the standard CEL default for the honda ecu.

I think the CEL will only happen if the ecu sees a negative value, could be your ground too. make sure you have a damn good ground. I just went through this with my car, I ended up having to bend the probe on my trottlebody so i could get 100% trottle as my TPS sensor was fine, but the trottlebody must hate me. Either way, my problem now is inorder to set my car to 100%, i'm at 8% trottle at idle, which means the IACV doesn't kcik open, so my car now idles like a rotary. Either way I'm now looking for a new trottlebody and hopefully i'll figure out this again when i transfer the TPS sensor over.

 

I'm going to play with it more today...

I'm getting kinda worried that the GM TPS doesn't output like the Honda sensor... :/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson &raquo;</TD></TR><TR><TD CLASS="quote">I'm going to play with it more today...

I'm getting kinda worried that the GM TPS doesn't output like the Honda sensor... :/</TD></TR></TABLE>

I must have missed it but why the GM TPS?

 

what's wrong with stock TPS? What's the reasoning behind this GM TPS?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mad Cow &raquo;</TD></TR><TR><TD CLASS="quote">what's wrong with stock TPS? What's the reasoning behind this GM TPS?</TD></TR></TABLE>

My guess is a different TB.

As far as the TPS showing a resistance. It doesn't generate voltage, obviously. I'm guessing it's a potentiometer, and as the resistive load changes, the voltage drop across it changes, hence, the ecu sees different voltages.

-PHiZ

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ladysman &raquo;</TD></TR><TR><TD CLASS="quote">

I must have missed it but why the GM TPS?</TD></TR></TABLE>

BBK mustang TB.

Well, I got the engine to idle pretty good finally, and tryed messing with the sensor. The most I could get was -3% at where the sensor currently is. I'm pretty sure I can flip the sensor so I can adjust it to zero.

however, The engine doesn't want to rev...? As soon as I give it any throtal it seems like it hits a Rev Limiter. I've been told it should rev even though the TPS isn't correct yet...?

Any Ideas?

 

sounds like a wiring problem, mainly your output wire fromt eh TPS isn't going into the ecu.

the reason teh car is running like crap is because you rev the car, so more air comes into the motor, but if the ecu isn't seeing the TPS sensor change, it still thinks you are at 0% trottle.

also honda's TPS sensors raise in voltage as they increase trottle. so one test I always do is, plug it in and with a multimeter, turn it from closed to open, it shoudl go from 0v to 5v. this shows its got the correct range of motion, as all you need for the ecu is for it to be .5 to 4.5v.

 

my buddy has the same throttle body, he used a honda tps because of the way it rotates or some thing he was haveing the same problem his car ran like ****, im for more info if you need it i will find out what tps he used for shure.

 

bryson , this is the tps you need to use it comes from the 88 civic dx dual point motor, the volatage swing is diffrent then any other honda one and works on the mustange tb, you will have to make an adapter plate though for the sensor to bolt up, i hope this helps , any other ? just im me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1CYA &raquo;</TD></TR><TR><TD CLASS="quote">bryson , this is the tps you need to use it comes from the 88 civic dx dual point motor, the volatage swing is diffrent then any other honda one and works on the mustange tb, you will have to make an adapter plate though for the sensor to bolt up, i hope this helps , any other ? just im me </TD></TR></TABLE>

Bump... You sir have an IM...

 

http://www.diy-efi.org/gmecm/

Has the voltage ranges for some sensors. Not what you're looking for (TPS) unfortunatly, but the mailing list will have someone that will most likely have that info.

-PHiZ

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PHiZ &raquo;</TD></TR><TR><TD CLASS="quote">http://www.diy-efi.org/gmecm/

Has the voltage ranges for some sensors. Not what you're looking for (TPS) unfortunatly, but the mailing list will have someone that will most likely have that info.

-PHiZ</TD></TR></TABLE>

Thanks for the info Phiz, but to make things easier, I am most likely just going to ditch Rons intake mani for an Edelbrock. I hate this ghetto fab ****.

I just spent the last 2 hours trying to hack up a stock TPS so it would work with the mustang TB...**** that.

I also don't have the IAC (which would be nice).