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Old 05-20-2019, 11:55 AM   #1
mazzo
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Strange TPS issue

So I had a code 1231 so I replaced my TPS with a new one. Now I experience something strange - when I am not stepping on gas, the rpm will maintain at 1.5krpm (used to be ~800rpm). When I pop the hood while the engine is running, I check the throttle body and the flap is closed. The cables are not tight and I don't see why it's thinking I have partial throttle. Check engine light for sure is on, and this time it's 1222.

I push up the throttle body arm (the one with hook at the end) a bit (it's already close so I can't push much...maybe 1/10 of 1mm?), and the rpm drops back to ~800. I think the new TPS is problem here. Any one thinks the same? Or could it be that my return springs on throttle is not tight?

A side question - is the hook on the throttle body arm suppose to hook up to some sort of return spring? However, I checked realoem but I can't find anything about this...any idea?
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Old 05-20-2019, 03:11 PM   #2
Poorhouse
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Did you set the new TPS per the Bentley specs?

I just replaced mine. There are some electrical tests you have to run to adjust it properly.
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Old 05-20-2019, 03:17 PM   #3
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your adjustment is off
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Old 05-20-2019, 11:35 PM   #4
mazzo
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Guys, when I put on the TPS I tested the ohm reading, so I know when it's close the reading is zero.
Anyway, I when back and start taking things apart, and take the TPS out to check (just in case) and sure enough - the reading is 0 when throttle body is closed (especially when I close it very slowly)
Now the interesting part, when I put them back again, this time I make sure every step (down to individual bolt that I tight) I check the TPS and make sure I hear the 'click' when I close the throttle body slowly, and this time I found something - turns out when I tighten my bolts for the throttle body itself, when one of the bolt (especially the upper right one) is tighten to certain level, I would NOT hear the click when I close the throttle body...very puzzling...
I checked the butterfly door and I see no reason it's the cause of it. I also checked the TPS and there's plenty of room below the housing, so I am not sure why tightening the bolt is causing.
Any idea?
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Old 05-23-2019, 02:21 AM   #5
S.J.1981
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Quote:
Originally Posted by mazzo View Post
Guys, when I put on the TPS I tested the ohm reading, so I know when it's close the reading is zero.
Anyway, I when back and start taking things apart, and take the TPS out to check (just in case) and sure enough - the reading is 0 when throttle body is closed (especially when I close it very slowly)
Now the interesting part, when I put them back again, this time I make sure every step (down to individual bolt that I tight) I check the TPS and make sure I hear the 'click' when I close the throttle body slowly, and this time I found something - turns out when I tighten my bolts for the throttle body itself, when one of the bolt (especially the upper right one) is tighten to certain level, I would NOT hear the click when I close the throttle body...very puzzling...
I checked the butterfly door and I see no reason it's the cause of it. I also checked the TPS and there's plenty of room below the housing, so I am not sure why tightening the bolt is causing.
Any idea?
That is normal, since when tightening down the screws the TPS moves slightly. In this case you adjust the TPS to be just slightly off, so that when you tighten the screws the TPS clicks/gets within specs.
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Old 05-23-2019, 10:51 AM   #6
mazzo
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Yes, I think I need to do that - because now I think the gap on throttle body is too big and is causing vaccum leak randomly... But it's also hard because it will be a lot of trial and error (adjusting the TPS with throttle body on the mounting point is almost impossible... :< )
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Old 05-23-2019, 12:23 PM   #7
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you need to remove the TB to do this correctly
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Old 05-23-2019, 03:50 PM   #8
mazzo
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Yeah MrBurgundy...That's why I said it will be lots of trial and error...
I am also thinking if I should put some gasket sealant on the throttle body gasket (there wasn't and I don't think it's there by default)....should I?
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Old 05-24-2019, 11:49 AM   #9
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Yeah MrBurgundy...That's why I said it will be lots of trial and error...
I am also thinking if I should put some gasket sealant on the throttle body gasket (there wasn't and I don't think it's there by default)....should I?
You don't need gasket sealant. Pull the old gasket off and keep it intact. Use cereal box cardboard and trace the old gasket onto the new one. Cut it out. Done. Make sure the intake and tb surfaces are clean before re-installation.
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Old 05-24-2019, 11:52 AM   #10
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You can buy a new gasket for like 2 bucks
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Old 05-24-2019, 11:52 AM   #11
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Originally Posted by mazzo View Post
Yeah MrBurgundy...That's why I said it will be lots of trial and error...
I am also thinking if I should put some gasket sealant on the throttle body gasket (there wasn't and I don't think it's there by default)....should I?
Clean mating surface and i use a very thin coat of silicon grease on paper gaskets, to prevent them from tearing when installing/handling and to ensure (in my head) a proper seal.

Generally you do not need any kind of additional sealants when installing paper gaskets, but i like to be safe and silicon grease does not dry and will last...forever.
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Old 05-24-2019, 12:01 PM   #12
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You can buy a new gasket for like 2 bucks
That is true, but you wont get to enjoy a bowl of cereal
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Old 05-26-2019, 07:15 PM   #13
mazzo
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Good advise guys!! Thanks!!
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