TPS values

MisterAl · #1 04-06-2009, 03:44 PM

Hi, my 92 SVX threw a #31 fault code, rough idle and engine pinging. I took the TPS off and it reads from 0.18k ohms to 5.3k ohms and changes smoothly all the way. Do I need a new one?

Trevor · #2 04-06-2009, 07:03 PM

Quote:

Originally Posted by MisterAl

Hi, my 92 SVX threw a #31 fault code, rough idle and engine pinging. I took the TPS off and it reads from 0.18k ohms to 5.3k ohms and changes smoothly all the way. Do I need a new one?

The manuals do not specify the overall resistance of the TPS, however yours would seem OK. Make sure you adjust the sensor position with the throttle fully closed, to 0.45 - 0.55 volts. I have had no trouble in achieving the mean of 0.5 volts. Refer the how too section if you have a problem with this.

MisterAl · #3 04-07-2009, 02:11 PM

Hi Trevor, thanks for your reply. I found someone who has the workshop manual and he said that the values shown in that are: between centre and an outside pin, 10k - 12k ohm when fully closed, and 3k to 5k when fully open. ie considerably higher than mine.
However the reading I have of 5k between the outside pins is correct. I suppose I should just go for the 0.5v reading and see if that solves the problem.

K_Dub · #4 04-07-2009, 03:44 PM

As long as the sweep is smooth then your TPS should be fine, just needing adjustment. The only reasons to replace (as far as I know) is when your readings jump erratically when you sweep through, or if you've gone to the end of your adjustable range and still haven't hit a solid 5ohms. When mine went bad it was very obvious when I measured the sweep with a multimeter: values jumped all over from high to low at partial throttle, but were smoother near WOT. Just get it dialed in to 5ohms and you'll be a happy camper.

oab_au · #5 04-07-2009, 07:11 PM

Quote:

Originally Posted by K_Dub

As long as the sweep is smooth then your TPS should be fine, just needing adjustment. The only reasons to replace (as far as I know) is when your readings jump erratically when you sweep through, or if you've gone to the end of your adjustable range and still haven't hit a solid 0.5volts. When mine went bad it was very obvious when I measured the sweep with a multimeter: values jumped all over from high to low at partial throttle, but were smoother near WOT. Just get it dialed in to 0.5volts and you'll be a happy camper.

Fixed your typo.

Harvey.

K_Dub · #6 04-07-2009, 07:17 PM

Quote:

Originally Posted by oab_au

Fixed your typo.

Harvey.

I should leave the tech talk to those who know their stuff.

Thanks Harvey.

Trevor · #7 04-07-2009, 07:34 PM

Quote:

Originally Posted by MisterAl

Hi Trevor, thanks for your reply. I found someone who has the workshop manual and he said that the values shown in that are: between centre and an outside pin, 10k - 12k ohm when fully closed, and 3k to 5k when fully open. ie considerably higher than mine.
However the reading I have of 5k between the outside pins is correct. I suppose I should just go for the 0.5v reading and see if that solves the problem.

I do not know what sort of manual your friend has, but the figures quoted do not make sense. Measurement from the centre pin, i.e. the moving element, should read near zero ohms fully one way, and total resistance the opposite way. Your 5K ohms reading appears to add up as correct.

Yes, adjust for volts and go from there.

MisterAl · #8 04-08-2009, 02:08 PM

Thanks everyone, I'll try it out as soon as it stops snowing.