Symptoms of TPS voltage being incorrect??

[ace0073]

Ok, first off this may be more of a general KA question but since the car I am referring to is turbo....i am posting it here. I am actually asking for another member but thats besides the point. Question is: What are the symptoms of TPS voltage being off? The situation was created when we installed some ITB's on my boys turbo KA 510. When I tried to setup the TPS, I realized that since the throttle travel was drastically different (shorter) there was no way to get the voltage correct. If i set it correct at closed throttle then it was off at WOT and vice versa. I ended up setting it at closed throttle which I am not sure if that is best. Not sure if this is a NOOB question or not but, honestly, I dont know anything about how the computer uses the info from the TPS so I am asking. Any 'useful' information will be appreciated. thank you

also, considering the voltage can be set at WOT or idle, if it is going to be incorrect, which one is best to set at?

[neverlift]

so itb with a plenum and maf installed ? interesting to say the least

you will have to find a tps that has a faster rate of increase. (ie a short stroke with same 0~5 volt output....

g/l

[ace0073]

yep, i will post pics tomorrow or later today. what i did was to make an adapter plate and an adapter shaft that let the stock TPS mount to the ITB's. also, after reading my own question i have considered some obvious items: lets see TPS-throttle position sensor, based on context clues seems to me that if it is off then the computer reads that the throttle is in a different position than it really is. seems pretty simple. symptoms of that would be or could be...in an extreme case symptoms may be:

if the car is at WOT and the computer thinks its at half throttlethen you will prolly be really lean and the car will feel slowright since the computer will be giving an output equal to half throttle but you actually have input for full throttle that in turn could cause u to misfire and all sorts of other things because while the TPS says half throttlethe MAF is saying 'Im sucking in WOT amounts of air.' i would think that in that case the computer could be confused and not really know what to do.That is all a guess based on the part name TPS. Please correct me where im wrong because the car is running really weird and does not want to boost or have power.

[72nismo]

Hmmm. Interesting.

[neverlift]

exactly, the maf gives the ecu the amount of air flowing, then looks at the tps/rpm to give your fuel and timing.

If you have it set correct at idle and it only goes to lets say 2.5volts from that, then the ecu is seeing roughly half throttle and wot afm numbers its going to "fight" itself till it gets a ~close~ x y axis to use so for wot you probably are not getting enough fuel and you timing is probably way too high

these gixxer ITB? if so I think the tps will work or can be made to work. ANother q, do you have the ability to rom tune, if so get on hybridka and see if gabe can hook you up with how to swap out tps/maps(the man can do anything... with a nissan ecu)

again good luck

[WDRacing]

In short, TPS settings effect the entire air/fuel curve and the timing curve. If it an auto they also effect shifting and shift points.

I know because I didn't realize how important it was and eye balled mine on my Skyline a few years back...it ran/drove for crap until set properly.

WD

[72nismo]

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[Gabes13]

that my friend, is a bamf

[neverlift]

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I've seen this before I think...

also, intake pipe = fail man j/p if it works dew eet but why? wait thats a p60 maf(q45)? I see

[72nismo]

I've answered the intake pipe question before I will repeat 1 more time.It is a Datsun 510 and we don't have much space to put a straight pipe and we need to have at 12" - 18" of intake pipe for the set up to run properly.In regards to the MAF it is a stock 95 240sx MAF.

[neverlift]

oh yeah, I remember now, maf must just look big to me at the time, not so much now...

why did it need to be so far, I had my z32 maf(when draw through) about 3 inches away

blow through ftmfw btw No stall or idle issues

anyway clean *** setup.

[72nismo]

Not sure but anybody I have dealt with have had issues when going with a short intake.Might just be the JWT set up. Friend of mine had a shorter set up car would turn on but every time he would rev it or come to a stop it would shut off until he changed it and got the same S pipe no problems since then.Were you located at? Thanks for compliments.

[neverlift]

kinda like this

tb< 90* pipe<maf<45* pipe w/bov< cooler < hot pipe < turbo trubo inlet is simple as well,: turbo<45* pipe with a filter on it, kinda to the corner like yours..

no I have heard of the dreaded s pipe config. just never saw the need. Also is the bov recirc'd? that is important to a suck through maf, unless you have a good bov... I'd call you tune manufacturer and ask if you could just move the maf onto the charge pipe(cold side IMHO as close to tb as you can!) on the tune without ill effects. I started out draw through and quickly found I like blow through better, no more stalls after shifts, no more smoke at idle or metered air getting dumped resulting in wasted fuel/stall

I saw a 510 in the junk yard the other day it was sad, decent shape for its age, still had a motor in it

[72nismo]

I have a Blitz bov not recirc. Different question about sparkplugs. What is the correct gap for some Iridium Sparkplugs?

[WDRacing]

The gap question always depends on the ignition strength and the amount of boost being run. What I recommend is to start with .038 and see if you get any stuttering or spark blow out on boost. If not, leave it...if yes reduce the gap to .035 and so on until you reach a minimum of .028. Once you get that low you need an ignition coil or something to increase the amperage to the plug.

WD

[72nismo]

Ok. I will try that.

Thanks

[72nismo]

How would the car react if the TPS is no good? Does anybody know?