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  #61  
Old February 25th, 2017, 20:19
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

Set the timing today -- it was off by just a few degrees according to the toothpick holes

It starts easier now and runs better cold but no change when it warms up -- idle still drops and it coughs and spits

Get it up to 1500 plus rpm and it doesn't sound bad but let it drop to idle from there and it barely runs

I've got a friend with a real scanner -- wants to see it -- maybe his scanner will tell me something -- just have to trailer it to his shop
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  #62  
Old February 25th, 2017, 21:22
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Re: Throttle position sensor - Voltage on output wire

one thing to try is pop the iac and clean it. might be sticking or dirty
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  #63  
Old February 26th, 2017, 09:40
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

Did that -- also tried a different IAC

no change
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  #64  
Old February 26th, 2017, 17:54
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Re: Throttle position sensor - Voltage on output wire

Are you going to do a compression check or not ??????
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  #65  
Old February 26th, 2017, 18:53
Waynerd Waynerd is offline
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Re: Throttle position sensor - Voltage on output wire

Don't forget a leak down test as well. Unless the comp readings suck.
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  #66  
Old February 27th, 2017, 00:33
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

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Originally Posted by Bobbie View Post
Are you going to do a compression check or not ??????

I have to although I've been avoiding it -- Been hoping to stumble across the problem and not have to pull the head

If I do find I need to pull the head I'll be looking for a replacement TUPY head

I'm not going to put much work into a head thats prone to cracking
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  #67  
Old February 27th, 2017, 06:07
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Re: Throttle position sensor - Voltage on output wire

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Originally Posted by Heavyopp View Post
I have to although I've been avoiding it -- Been hoping to stumble across the problem and not have to pull the head

If I do find I need to pull the head I'll be looking for a replacement TUPY head

I'm not going to put much work into a head thats prone to cracking


Ok,You can lead a horse to water but,you can't make him drink.
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  #68  
Old February 27th, 2017, 07:55
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Digger87xj Digger87xj is offline
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Re: Throttle position sensor - Voltage on output wire

So I kind of scanned through and didn't see that anyone answered your original question.
Yes, there is supposed to be 5v on the signal wire when unplugged. It's a carrier voltage.

The three pins on the TPS harness should test as follows, KOEO, sensor unplugged:
Pin 1: sensor ground, 0v
Pin 2: sensor signal, 5v
Pin 3: 5v supply, 5v

All 3 wire Chrysler sensors test out this way, though pin order may be different per sensor.
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  #69  
Old February 27th, 2017, 09:38
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

Quote:
Originally Posted by Digger87xj View Post
So I kind of scanned through and didn't see that anyone answered your original question.
Yes, there is supposed to be 5v on the signal wire when unplugged. It's a carrier voltage.

The three pins on the TPS harness should test as follows, KOEO, sensor unplugged:
Pin 1: sensor ground, 0v
Pin 2: sensor signal, 5v
Pin 3: 5v supply, 5v

All 3 wire Chrysler sensors test out this way, though pin order may be different per sensor.

I've searched many forums in the past month -- this is the 1st time I have seen this answered this way

Most threads just go unanswered -- In fact all the threads I've seen have gone unanswered

I kinda just gave up looking for the source of the voltage on the sensor wire

I still get P0122 sometimes -- tried 3 TPS and all the same -- wasn't going to worry about it till I found the source of my troubles


Compression check this week -- Gotta see if I can source a decent compression check gauge -- I have one but I think it's for small engines -- has a rubber expanding plug for the spark plug end -- I've never used it -- Came with a bunch of tool I bought out of a barn
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  #70  
Old February 28th, 2017, 05:06
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Re: Throttle position sensor - Voltage on output wire

FYI, here's a TPS test procedures chart. I use a safety pin as a back probe.


.
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  #71  
Old March 1st, 2017, 20:23
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

Finally did a compression test today -- I was able to borrow a snap on compression test kit from a friend -- made it super easy

Cylinder# --------- PSI
1 ---------- 175
2 ---------- 0
3 ---------- 130
4 ---------- 162
5 ---------- 180
6 ---------- 178

I'll pull the valve cover tomorrow and see what is going on -- I have the stuff to do a leak down test if it isn't obvious
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  #72  
Old March 2nd, 2017, 06:41
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Re: Throttle position sensor - Voltage on output wire

hmm 2 seems a little low. i would double check that the tester had a good seal on that cylinder.
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  #73  
Old March 2nd, 2017, 08:58
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

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Originally Posted by 90xj06 View Post
hmm 2 seems a little low. i would double check that the tester had a good seal on that cylinder.
I though the same thing -- did it 3 times -- 0,0 and 0 is what I got
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  #74  
Old March 3rd, 2017, 20:09
Heavyopp Heavyopp is online now
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Re: Throttle position sensor - Voltage on output wire

Pulled the valve cover off and found the pushrod for cylinder 2 exhaust valve disconnected from the rocker arm -- It was just laying there in the hole -- Bent like "S"

The exhaust valve is stuck open, spring is compressed as much as it can -- rocker is just loose on top

guess this thread about throttle position sensor issues is over...
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  #75  
Old November 21st, 2017, 08:28
JardCrocker JardCrocker is offline
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Re: Throttle position sensor - Voltage on output wire

Hi...i am a new user here. In my case TPS signal wire always has a little bit of voltage on it, even with it unplugged, but nothing like 4 volts, more like 1/2 a volt or so. No idea why it's like that, but it doesn't throw any codes, so I suspect it's an OEM design feature of some sort.
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