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slvr dak
Dodge Dakota
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11/12/2002
08:11:05
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 Subject: TPS, Three wires and a questions
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On the tps, there are three wires.
I know that the middle one is the one
to read when doing the TPS mod.
My question is, which wire does
the computer read to adjust spark
timing and fuel/air?
Is it just the middle one, or does it
calabrate all three?
thanks
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Pistolero
Dodge Dakota
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11/12/2002
09:35:25
| RE: TPS, Three wires and a questions
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I don't know for sure, but I'd guess that it's just the middle one. Since the TPS is just a potentiometer (adjustable resistor), the two outside leads would be a plus and minus voltage reference, like ground and +12, and the middle lead carries the voltage changes out to the PCM.
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buzzbass
Dodge Dakota
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11/12/2002
09:53:34
| RE: TPS, Three wires and a questions
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Don't do that mod. It doesn't work. Screw what speedtweaks says. You're just going to screw up a perfectly good sensor and they're not cheap to replace. If the truck starts backfiring through the Throttle Body after you do the mod, you'll know why. Then you'll have to teplace the sensor. Been there, done that...............Don
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Troy
Dodge Dakota
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11/12/2002
11:22:38
| RE: TPS, Three wires and a questions
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I had to order a new sensor myself. I couldn't tell much (if any) difference after doing the mod. Now I have a screwed up TPS, and my wallet is $50 lighter for the new one. I don't recommend it either. I had mine set at .736.
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Texas Todd
Dodge Dakota
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11/12/2002
11:53:25
|  RE: TPS, Three wires and a questions
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I haven't done the mod yet, first I've heard any negatives about it, what engine?
Todd Bouton
01, QC 4.7, 5spd, HO cams, Homebrew intake with ported TB, no belt clutch/fan,
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graphiteRT
R/T
11/12/2002
11:57:55
| RE: TPS, Three wires and a questions
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Todd, the TPS works off of _RELATIVE_ voltages, not absolutes as the TPS mod folks believe. As long as the operating range is within .26V-4.49V it doesn't matter what your resting or idle voltage is. For the '01 the PCM will transition to off idle tables at .06V over the idle voltage and it will transition to WOT tables at 2.069V(going from memory) over the idle voltage. The PCM doesn't care what your idle setting is because it registers that voltage as a baseline at each "key on" event.
That mod *may* have worked some years ago, but it doesn't work on OBD-II vehicles.
Bob
'01 Graphite CC R/T, MP headers, Magnaflow muffler into 'Cuda style exhaust, M1 2bbl, ported 2.02 R/T heads, custom grind cam, Crower SS rockers, Paxton Novi2000, Boyd's 20s w/Dunlop SP9000s
Soon: Viper 4 wheel discs
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Pistolero
Dodge Dakota
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11/12/2002
12:38:12
| RE: TPS, Three wires and a questions
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Thanks, graphiteRT...I've got a 2002 truck, and this is the kind of real world information that I need to make a good judgment on what I can try without fear of messing up unseen and untold other things...the things that you never hear about happening when someone says DO THIS, IT'S GREAT!!
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Texas Todd
Dodge Dakota
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11/12/2002
14:20:45
|  RE: TPS, Three wires and a questions
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graphiteRT (Bob)
NIce Wheels those Boyds.
Thanks for the input.
My last post basically has my mods.
For instance, I'm not going to first go with a 'Cat-Back', when dynos rarely show any gains to a basically stock truck.(4.7), just so it can piss my neighbors off.
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sicminds
GenIII
11/12/2002
14:48:27
| RE: TPS, Three wires and a questions
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Message:
So, graphiteRT
Whats the the tps supposed to read when
it is WOT? Mine sits at .64 when at idle
and gets up to 3.8 when WOT. If my
calculations are correct, then that
means i am only at 70% absolute voltage.
So your saying that the TPS can read all the way up to 4.49V at WOT with out triping the check engine light or your sayin that is can idle at 4.49 and then increase when the pedal is pressed
And what do you think of the Venom 400?
Click here to see venom 400
now you know thats..................
sic
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graphiteRT
R/T
11/12/2002
15:06:29
| RE: TPS, Three wires and a questions
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Message:
The voltages I noted earlier are the absolute upper and lower limits. Anything beyond that trips a code for being out of spec. Been a while since I measured mine, but I believe it was ~.47-3.6x range. WOT starts at 83% TPS setting on mine, FWIW.
Sorry, but don't have any personal experience to offer on the Venom deal except to say that any piggy back type controller will have limited success and doubtful long term consistency. What people don't understand is that the newer OBD-II computers are pretty smart. Not only does the PCM supply input to the engine in the form of fuel and spark tables, but it also has tables for expected results from those inputs. This comes from many years of testing on the part of DCX.
Maybe not the best explanation, but it's basically like this:
PCM supplies X parts of fuel and Y units of spark based on sensor inputs and load conditions. At the same time it is pregroammed to expect Z as a reading on other sensors like the O2, ECT, etc. If it doesn't see this result, it goes into adaptive, looking up alternate tables and computing until it finds a pre-programmed table that matches the inputs to the outputs it monitors. You cannot change this short of a custom flash to mod the internal tables. Changing things like IAT, etc. has unpredictable results and is purely a shot in the dark. I doubt anyone on this board has any idea what the result of an IAT sensor move truly does or if it is even desirable. The assumptions that it simply adds fuel and spark is both misguided and misinformed about the way current PCMs operate. BTW, this is basically OBD-II spec technology, not something unique to the Dodge.
Kinda rambled on a tangent, but the point being that no add-on type box is effective long term with any reasonable predictability and all should be considered nothing more than band-aids.
Bob
'01 Graphite CC R/T, MP headers, Magnaflow muffler into 'Cuda style exhaust, M1 2bbl, ported 2.02 R/T heads, custom grind cam, Crower SS rockers, Paxton Novi2000, Boyd's 20s w/Dunlop SP9000s
Soon: Viper 4 wheel discs
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chris
Dodge Dakota
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11/12/2002
17:58:35
| RE: TPS, Three wires and a questions
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Graphite, those are some bad ass wheels dude. The best set of 20's iv seen on a dakota. Very clean looking truck, very. Now, where can I get a pair! haha, man those are clean lookin wheels dude. Nice buy, very nice.
--
CHris
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j
GenIII
11/12/2002
18:24:46
| RE: TPS, Three wires and a questions
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Graphite R/T-- What kind of flash are you running with your mods? Are you saying that something like the Split Second ARC-2 that intercepts the signal from the mass airflow meter (or map sensor) before going to the pcm to adjust air/fuel would not work on our trucks. Thanks.
2000 4.7 CC auto, clear corners, Magnaflow catback, Kenne Bell s/c.
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sicminds
GenIII
11/13/2002
11:57:15
| RE: TPS, Three wires and a questions
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I think he is saying that we cant trick the PCM's inputs without tricking the outputs?
Cause he said that if we mod the inputs the pcm still looks at the output sensors to see if we are running correctly. If the outcome is not correct then the pcm searches the tables to find what works.
now you know thats..................
sic
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slvr dak
Dodge Dakota
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11/13/2002
14:26:20
| RE: TPS, Three wires and a questions
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whats the highest range I can adjust the TPS to?
Do i risk killing the other parts? I have an extra TPS sitting by just in case. I have read that the tps should read 4.5v at wot. Can it read higher then that to get better throttle response?
I know that the TPS is only suplied with 5v, what if i was able to suplie it with 6v and had it set so when i was WOT the tps would read 6v. Would this damage anythign?
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graphiteRT
R/T
11/13/2002
15:07:33
| RE: TPS, Three wires and a questions
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j - I'm currently running the B&G M1 flash, but will be moving to something else shortly that will work with the blower.
To answer your question on the ARC-2, any piggyback box like that that modifies the signal of only a sensor or two will never be able to achieve the same results as a custom flash. It's just not possible these days due to the adaptive logic the PCMs have evolved to. I affectionately call those aftermarket boxes "band-aids". Not to suggest they are junk, just that their effectiveness/usefulness is limited.
slvr dak - I'd highly recommend buying a factory service manual for your truck, then reading up on what some of the basic sensors do and their operating ranges. You're heading down some dead end streets with your approach and reading up in the manual will save you some grief.
Bob
'01 Graphite CC R/T, MP headers, Magnaflow muffler into 'Cuda style exhaust, M1 2bbl, ported 2.02 R/T heads, custom grind cam, Crower SS rockers, Paxton Novi2000, Boyd's 20s w/Dunlop SP9000s
Soon: Viper 4 wheel discs
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slrv dak
Dodge Dakota
JOIN HERE
11/13/2002
17:38:18
| RE: TPS, Three wires and a questions
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I have done some reading up on the TPS in my dakota factory service manual
I know that it is supplied with 5v dc and when at wide open throttle, it should see 4.5v. I am just wondering what would happen it I sent 6v or 5.5 as a reading to the pcm.
I guess i am just trying to figure out how that Venom 400 works or how some of the "band aid" boxes work.
I think that the boxes will work when only used when needed. If you leave it on all the time I agree that the computer will change back to other data stored.
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graphiteRT
R/T
11/13/2002
21:19:01
| RE: TPS, Three wires and a questions
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If you read the manual, you'll see that it tells you anything 4.5V or higher is out of spec and it will trip a code.
Bob
'01 Graphite CC R/T, MP headers, Magnaflow muffler into 'Cuda style exhaust, M1 2bbl, ported 2.02 R/T heads, custom grind cam, Crower SS rockers, Paxton Novi2000, Boyd's 20s w/Dunlop SP9000s
Soon: Viper 4 wheel discs
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slvr dak
Dodge Dakota
JOIN HERE
11/14/2002
11:12:03
| RE: TPS, Three wires and a questions
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So those boxes must only be putting the voltages to 4.5 then. Or is it able to be higher when at wot? Then that means those boxes really only work on trucks that have low set voltages in the first place.
Somthing that they could get in trouble for.
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Demon Dakota
DakotaEnthusiast
11/14/2002
12:16:13
| RE: TPS, Three wires and a questions
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If the TPS mod doesn't work, then why is my slight off idle stumble gone now that I've altered the TPS? Try to explain that one with the manual. I know what it says the sensors are supposed to do, and I know what the voltages are, but my truck does not have the same stumble, and it (the TPS mod) was the only change.
K&N Drop in AF
True Dual exhaust and removed third cat
HO Cams & HO Intake
Modified TB
Autolite 3923 Plugs
TPS @ .76 VDC
IAT Adjuster Mod
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