Jump to content
SAU Community

Recommended Posts

I have a stock series 2 manual and when i got it, it was the smoothest car ive ever driven. I took it to my mechanic shop who is a well known dyno shop in melbourne. After getting it back its not smooth on and off the throttle, its got a little jerk. more noticeable when going realy slow but never the less noticable all the time. Its starting to give me the shits. I took it back to my mechanic and he said that theres nothing wrong with it, but i know what it was like before. so im stuck with it. Apparently the only thing they adjusted was the tps (throttle position switch). Does anyone know much about this switch and if it can be adjusted without hooking it up to a computer and where it is located?

Help anyone

Thanks

Stu

Link to comment
https://www.sau.com.au/forums/topic/275314-stagea-jerky-on-and-off-throttle/
Share on other sites

i know exactly what you mean. i accidently did it once when i was working on my old 32. it feels like the accelerator is lagging, and then all of a sudden it kicks in. and yes, it is related to the TPS. i cant remember which way it is but its if the TPS's closed voltage is a bit too high or too low it will cause this.

the tps is on your throttle body just before the inlet plenum. it needs to be set to the correct voltage when the throttle is closed, 0.3-0.5v. if your any good with a multimeter you can fix it up yourself, otherwise i'd take it back and tell them to get it sorted.

i know exactly what you mean. i accidently did it once when i was working on my old 32. it feels like the accelerator is lagging, and then all of a sudden it kicks in. and yes, it is related to the TPS. i cant remember which way it is but its if the TPS's closed voltage is a bit too high or too low it will cause this.

the tps is on your throttle body just before the inlet plenum. it needs to be set to the correct voltage when the throttle is closed, 0.3-0.5v. if your any good with a multimeter you can fix it up yourself, otherwise i'd take it back and tell them to get it sorted.

Thank you very much, it sounds as though your on the money. Another question is how do u adjust it? is there some sort of screw to adjust the voltage? What does it look like? the only thing i can see on the throttle body is a little black solonoid type thingy with about 6 wires coming out of it. Would that be it?

Thanks again

stu

Edited by sturb25

best i can do for you at the moment, is this pic. the black part circled in red is the TPS. the yellow circle is one of two bolts you loosen to be able to adjust the TPS, the other bolt is at the bottom of the TPS, you'll have to remove the covers to see it. once these are loosened, you don't have to remove them, just loosen. you turn it clockwise/anti-clockwise to adjust the set voltage.

you need a multimeter, one probe goes to ground/-ve, and the other goes to the TPS variable output (without rooting though wiring diagrams to find it, or probing for it, i cant tell you exactly which one it is) either on the TPS itself or the TPS signal input on the ecu plug. at the TPS itself should be the easiest to probe. then just turn the TPS until you get the correct voltage. then do the bolts back up, and recheck the voltage is right and nothing has moved while tightening it up. also take note that you have to set the voltage with the throttle closed.

another way to do it without a multimeter is to hook it up to a laptop and use a consult interface and monitor the voltage through that while you set it.

i suppose if you don't want to stuff around with all this you could just loosen the bolts, slightly move the TPS in one direction, tighten it back up and go for a drive and see how it feels, if its worse turn it the other way. its not ideal and you would still want to get it checked properly but it may help make it more drivable until then.

post-34711-1245321788_thumb.jpg

Edited by QWK32
best i can do for you at the moment, is this pic. the black part circled in red is the TPS. the yellow circle is one of two bolts you loosen to be able to adjust the TPS, the other bolt is at the bottom of the TPS, you'll have to remove the covers to see it. once these are loosened, you don't have to remove them, just loosen. you turn it clockwise/anti-clockwise to adjust the set voltage.

you need a multimeter, one probe goes to ground/-ve, and the other goes to the TPS variable output (without rooting though wiring diagrams to find it, or probing for it, i cant tell you exactly which one it is) either on the TPS itself or the TPS signal input on the ecu plug. at the TPS itself should be the easiest to probe. then just turn the TPS until you get the correct voltage. then do the bolts back up, and recheck the voltage is right and nothing has moved while tightening it up. also take note that you have to set the voltage with the throttle closed.

another way to do it without a multimeter is to hook it up to a laptop and use a consult interface and monitor the voltage through that while you set it.

i suppose if you don't want to stuff around with all this you could just loosen the bolts, slightly move the TPS in one direction, tighten it back up and go for a drive and see how it feels, if its worse turn it the other way. its not ideal and you would still want to get it checked properly but it may help make it more drivable until then.

post-34711-1245321788_thumb.jpg

Thanks again. will let you know if i have any dramas

my autech does this too...

if u put the foot in to like half way in a high gear... like 4th at 60ks... and pull it back to a 1/4 of throttle it jolts like 2 or 3 times... if u rip the foot off it stops instantly... would this be the same prob?

why would the voltage change? just ware and tare?

my autech does this too...

if u put the foot in to like half way in a high gear... like 4th at 60ks... and pull it back to a 1/4 of throttle it jolts like 2 or 3 times... if u rip the foot off it stops instantly... would this be the same prob?

why would the voltage change? just ware and tare?

sounds as though youve got a different problem, mines like a tiny jerk and it only does it when your on and off throttle all the time. hardly noticable but more noticable when your driving at 2-5km/h realy slow.

Hope that helps, but probably not!

best i can do for you at the moment, is this pic. the black part circled in red is the TPS. the yellow circle is one of two bolts you loosen to be able to adjust the TPS, the other bolt is at the bottom of the TPS, you'll have to remove the covers to see it. once these are loosened, you don't have to remove them, just loosen. you turn it clockwise/anti-clockwise to adjust the set voltage.

you need a multimeter, one probe goes to ground/-ve, and the other goes to the TPS variable output (without rooting though wiring diagrams to find it, or probing for it, i cant tell you exactly which one it is) either on the TPS itself or the TPS signal input on the ecu plug. at the TPS itself should be the easiest to probe. then just turn the TPS until you get the correct voltage. then do the bolts back up, and recheck the voltage is right and nothing has moved while tightening it up. also take note that you have to set the voltage with the throttle closed.

another way to do it without a multimeter is to hook it up to a laptop and use a consult interface and monitor the voltage through that while you set it.

i suppose if you don't want to stuff around with all this you could just loosen the bolts, slightly move the TPS in one direction, tighten it back up and go for a drive and see how it feels, if its worse turn it the other way. its not ideal and you would still want to get it checked properly but it may help make it more drivable until then.

post-34711-1245321788_thumb.jpg

This is probably going to sound realy dumb but i want to get it right. when adjustinng the TPS u said to adjust it with the throttle fully closed. does this have to be done with the car running or ignition on. sorry it sounds pretty dumb but i dont want to stuff it up.

Thanks

Stuart

engine doesn't have to be running but ignition has to be on, so the put the key in the ON position.

My TPS was reading 5.1 volts so i changed it to 3volts. tightened it up and rechecked. it read 2.9volts, went for a drive and it felt better but still not 100% so i tried 3.5volts. it seems to of improved quite substantialy but its rasied my idle to around 1500rpm. Is this normal? I adjusted my idle screw on the throttle body which lowered it to normal rate. Should i have adjusted that?

Stuart

do you mind PMing me where you took it? i am thinking i might take mine somewhere to get adjusted but i need to know where not too go if that makes sense, not to pay out the workshop, but just i dont have heaps of money to waste paying to get jobs redone when they should be done right the first time.

My TPS was reading 5.1 volts so i changed it to 3volts. tightened it up and rechecked. it read 2.9volts, went for a drive and it felt better but still not 100% so i tried 3.5volts. it seems to of improved quite substantialy but its rasied my idle to around 1500rpm. Is this normal? I adjusted my idle screw on the throttle body which lowered it to normal rate. Should i have adjusted that?

Stuart

no, i think you misread, it should be between 0.3 to 0.5v, not 3.5v. thats why you have an increased idle, because the TPS voltage is way to high. the TPS output scale is from 0-5v, setting it to 3.5v is like telling the ecu you have your foot 3/4 the way on the throttle, hense high idle.

Edited by QWK32

From the R34 Service manual;

TPS voltage (ignition switch on, engine not running)

accelerator pedal released approx 0.5Volts

accelerator pedal fully depressed approx 4.2Volts

TPS voltage (engine running at approx 2000 RPM)

approx 0.6-0.7 volts

Its best to adjust the TPS when connected to Nissan Consult. You want the idle position to be below the point where the 'idle closed' switch is activated. You might get this right just by setting via voltages, but you might not

Had same issue with my R31 a few years back, drove to Bundalong and back to Melb on one tank, best fuel economy i ever had, although it did shit me each time i lifted of the pedal at 100kmh.

Had to feather the pedal for a less annoying drive.

The old tps died a day or two before i left, so popped down the wreckers got another did a quick adjustment which was

not spot on, hence the annoying drive.

When i got back first thing did was start fixing, I just adjusted by feel / listening to the idle without the multimeter.

I found the adjustment is very sensitive, 1mm and its out.

Even when re-tightening the bolt you can chuck it out, so hold the tps firm when tightening the bolts.

From memory I rotated the the tps anti-clockwise to its full adjustment, then slowly rotated clockwise until it the rough idle disappeared and became smooth but a was a bit high at 900-950rpm.

Re-checked the timing and base idle (which was out 3deg retarded prior to this) and all was good back down at the base 700-750rpm, geez it felt damn good to drive after.

Maybe 60mins of work including test drives.

no, i think you misread, it should be between 0.3 to 0.5v, not 3.5v. thats why you have an increased idle, because the TPS voltage is way to high. the TPS output scale is from 0-5v, setting it to 3.5v is like telling the ecu you have your foot 3/4 the way on the throttle, hense high idle.

Sorry i stuffed up my decimal points. i meant 0.35volts and its rasing the idle and it was set to start with at 0.51volts

Edited by sturb25

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yeah everyone always seems to refer to them as S13 wheels however they came on R32 Skyline, A31 Cefiro, C33 Laurel etc., and also came polished diamond cut or painted depending on the model. Congrats on your GTS purchase! I'd personally leave it NA.
    • In this thing about this 100% renewal energy stuff I hear no one really talking about anything other than power and fuel really Power and fuel, whilst being a huge part of how we use the billion year old Dinosaur juices, are only 2, of the probably thousands of things that we need to use it for in the chemicals industries for making nearly everything we use nowadays I'm all for a clean planet, but if we want to continue to have all the day to day appliances and stuff that we rely on everyday we will still need fossil fuels Whilst I do love science, and how it can bring innovation, there's really a limit to how far it can go in relation to "going green" As for EV's, unless your charging of your own solar panels, it isn't helping the environment when you consider the the batteries, the mining processes required,  the manufacturing process required, and how long a batteries (read: the vehicle) lasts long term If I was supreme dictator of the world, I would ban the use of sugar for fizzy drinks and food additives and use that for ethanol manufacturing, petrol engines would be happier, and people would be alot healthier  Disclaimer: Whiskey manufacturing would still be required, so says the supreme dictator of the world Same same for all the vegetable oils that get pumped into all our food, use that for bio diesel Disclaimer: the supreme dictator would still require olive oil to dip his bread in This would take some of heat off the use of the use of fossil fuels which are required for everything we use, unless you want to go back to pre 1800 for heat and power, or the early 1900's for plastics and every thing else that has come from cracking ethylene  Would I be a fair and just dictator, nope, and I would probably be assassinated within my first few months, but would my cunning plan work, maybe, for a while, maybe not Meh, in the end in an over opinionated mildly educated arsehole typing out my vomit on my mobile phone, which wouldn't be possible without fossil fuels And if your into conspiracies, we only need the fossil fuels to last until a meteor hits, or thermonuclear annihilation, that would definitely fix our need for fossil fuels for manufacturing and power issues for quite some time  Meh, time for this boomer to cook his lunch on his electric stove and then maybe go for a drive in my petrol car, for fun    
    • It really helps that light duty vehicles have absolutely appalling average efficiency due to poor average load. Like 25% average brake thermal efficiency when peak is somewhere around 38% these days. So even a 60% BTE stationary natural gas plant + transmission and charging losses still doing much better with an EV than conventional ICE. And that's before we get into renewables or "low carbon nonrenewable" nuclear which makes it a no-brainer, basically. In commercial aircraft or heavy duty diesel pulling some ridiculous amount of weight across a continent the numbers are much more difficult to make work. I honestly think in 5-10 years we will still be seeing something like the Achates opposed piston diesels in most semi trucks running on a blend of renewable/biodiesel. Applications where the energy density of diesel is just too critical to compromise. CARB is running trials of those engines right now to evaluate in real world drayage ops, probably because they're noticing that the numbers just don't work for electrification unless our plan is to make glorified electric trains with high voltage wires running along every major highway and only a token amount of battery to make it 30 miles or something like that after detaching. Transport emissions is not insignificant especially in the US, but yes there's a lot of industrial processes that also need to be decarbonized. I agree the scale of the problem is pretty insane but EDF managed to generate ~360 TWh from their nuclear reactors last year and this is with decades of underinvestment after the initial big push in the 70s and 80s. I don't think the frame of reference should be solar-limited. France is not exactly a big country either. Maybe it doesn't work everywhere, but it doesn't have to either. We just can't live off of fracking forever and expect things to be ok.
    • Yeah, all the crude is used for fuels and petrochem feedstocks (pesticides, many other chemicals, etc etc). But increasingly over the last few decades, much of the petrochem synthessis has started with methane because NG has been cheaper than oil, cleaner and easier and more consistent to work with, etc etc etc. So it's really had to say what the fraction either way is. Suffice to say - the direct fuels fraction is not insigificant. Heavy transport uses excruciatingly large amounts. Diesel is wasted in jet heaters in North American garages and workshops, thrown down drill holes in quarries, pissed all over the wall to provide electricity to certain outback communities, etc etc. Obviously road transport, and our pet project, recreational consumption camouflaged as road transport, is a smaller fraction of the total liquid HC consumption again. If you're talking aboust Aussie cars' contribution to the absolute total CO2 production of the country, then of course our share of the cubic mile of coal that is used for power generation, metallurgy, etc adds up to a big chunk. Then there is the consumption of timber. Did you know that the production of silicon metal, for example, is done in Australia by using hardwood? And f**king lots and lots and lots of hardwood at that. Until recently, it was f**king jarrah! There are many such sneaky contributors to CO2 production in industry and farming. NG is used in massive quantities in Australia, for power gen, for running huge water pumps (like, 1-2MW sized caterpillar V16 engines running flat out pumping water) for places like mine sites and minerals/metals refineries. And there are just a huge number of those sort of things going on quietly in the background. So NG use is a big fraction of total CO2 production here. I mean, shit, I personally design burners that are used in furnaces here in Oz that use multiple MW of gas all day every day. The largest such that I've done (not here in Oz) was rated to 150MW. One. Single. Gas burner. In a cement clinker kiln. There are thousands of such things out there in the world. There are double digits of them just here in Oz. (OK< just barely double digits now that a lot of them have shut - and they are all <100MW). But it's all the same to me. People in the car world (like this forum's users) would like to think that you only have to create an industrial capability to replace the fuel that they will be using in 10 years time, and imagine that everyone else will be driving EVs. And while the latter part of that is largely true, the liquid HC fuel industry as a whole is so much more massive than the bit used for cars, that there will be no commercial pressure to produce "renewable" "synthetic" fuels just for cars, when 100x that much would still be being burnt straight from the well. You have to replace it all, or you're not doing what is required. And then you get back to my massive numbers. People don't handle massive numbers at all well. Once you get past about 7 or 8 zeros, it becomes meaningless for most people.
×
×
  • Create New...