JR HAWK 9

iTrader: (3)

OK, I recently installed a ScanGaugeII and have been monitoring different PCM things. I noticed that every once in awhile my TPS would go from 0% at idle to some random number, like 6%/8%/4% and I think I even saw an 11% at one time. All I would have to do is shut the car off and restart it and it would be back to 0% again. I decided to replace the TPS sensor with a Standard brand one from RockAuto.

I installed it and when the car is not running but when I have the key turned on I am seeing a TPS angle of 0%...great, that's what it should be! As soon as I start the car (warm or cold) it goes to 3% and my idle is just fine at around 800rpms. Now after I take it around a couple blocks my TPS reading at idle goes down to 2% and then a little bit later it will drop down to 1%. At this time my car seems to be idling at around only 700rpm's or so. Then when my TPS angle decides to drop to 0%, the idle goes back up to around 800 or so. I don't know how the heck my TPS angle could be changing like that, as I KNOW it's not physically moving as the sensor says it is. My IAC counts are in the 55 area. The car runs and idles just fine, just I am confused as to why I am getting these different TPS readings when the throttle is not physically moving.

I do have a ported/polished throttle body that had a bit too much removed around the throttle plate which allowed too much air through at idle. I had the guy who did the polishing aluminum weld my idle air hole shut because with it opened up my IAC count was VERY low and the car tended to idle a bit higher than it should and took forever to come down when coasting. Now with that idle air hole closed up, like I said, I am seeing IAC counts in the mid 50's with this new TPS sensor. I do recall that with my old sensor I was seeing IAC counts in the mid 20's....

BTW, my replacement Standard TPS sensor is spring loaded while the stock one I took off the car is not. Is the stock one supposed to be??? I would think it would be more accurate if it was spring loaded.

does anybody have any idea to why my TPS sensor seems to have a mind of it's own?? lol

thanks!!!

JR HAWK 9

iTrader: (3)

update:

I cleared the PCM and tried it again with the new TPS sensor....did the same thing and this time my idle was at around 1,000 rpms. I then swapped in my stock TPS sensor and all is well after I started it up. It had 0% TPS and my idle was ~800rpms. I think either the new TPS is bad or it is calibrated a bit different than the stock one....either way it definitely seems to be TPS related seeing everything is fine with the stocker back in.

JR HAWK 9

iTrader: (3)

problem solved....


found out my old TPS is bad as it read something other than "zero" after a while of driving when at idle. Tried replacing it twice with Standard brand ones (which is the brand I prefer for all ignition related components, Blue Streak is the high end brand of Standard) and both of them did not work, they would immediately start out at like 4% (at idle) and then randomly go down to 0% and then back up to some other number all the while my idle would go from 700rpm to around 900rpms. It's like my PCM was trying to "learn" the TPS sensor like it was not calibrated the same. At idle my TPS voltage was always between 0.50V - 0.60V (AutoTap only reads to the tenth of a volt, and it reads 0.5V at idle running), so everything checked out there. I will say that the Standard ones had -a lot- better build quality when comparing it to the stock AC one.

I then tried a cheap Wells brand from Autozone and that seemed to have done the trick. I also took notice that the Wells brand was 90% identical to the stock AC one. It had the exact same mold, exact same patent numbers stamped in it, exact same inerds and sloppy build quality and it even had the same molded in raised circle that the stock one has "AC" stamped in it. The Wells one had the molded circle but just didn't have the "AC" stamped in it. I am pretty confident to say that the stock AC sensor is made by Wells or they both are made by some other company.

sciff5

iTrader: (1)

Having the same issue. So basically you just replaced the TPS and it went away?

01Z28M6

For what it's worth, and that may be nothing; you might experiment by putting a little resistance inline to the gauge. The reason I say this is that I had an issue when connecting something (electronic nitrous WOT switch) to my TPS wire that runs to the PCM. As it turned out, the feedback was screwing with the true 0-5 voltage going to the PCM from the throttle positioning sensor.

JR HAWK 9

iTrader: (3)

yep, I replaced it with a Wells TPS from AutoZone and it took care of the issue.

sciff5

iTrader: (1)

Thats a possibility. I meen I could add 20 feet of wire inline... just need to make sure I dont add so much resistence I cant get it to read 100% thrttle position at wot.

Looks like the only TPS sensors autozone has is duralast.

01Z28M6

In my situation I was told to add a 9.2k resistor. I don't think 20' of wire will add any significant amount. You can experiment with different values because resistors are very inexpensive and should cause no harm. Just make sure you put the resistor inline to the gauge and not between the sensor and the pcm.

sroach20

iTrader: (31)

i had the same problem with borg warner. i swapped it out with the bwd and mine read 2% at idle. i believe standard makes borg warner. i swapped a gm one on and it reads 0 at idle.

Blk_Ws6

iTrader: (4)

I wanted to know do the tps sensor mess with the car shift patterns like wot hitting the rev limiter?
And I bought a new one (tps) my throttle bodie was adjusted do I have to set it back like it was before installing the new sensor?

sroach20

iTrader: (31)

no need to adjust, just slap it on and do a tps reset.

Blk_Ws6

iTrader: (4)

How do you reset the tps?

sroach20

iTrader: (31)

unplug the tps, turn the car on for about 10 seconds (not started), turn the car off, plug the tps back in. it should now read 0 with the key on.