TPS, STPS and STVA sensors linked to temperature?

[Eric GSX1400K3]

Can anyone confirm if the TPS, STPS and STVA are influenced by temperature, ambient, engine oil or otherwise.

Scenario is this: daily commute to work, same freeway.  Early start on the road by 6am, ambient is nice around 19deg c. No FI light, bike runs sweet.

Same run home, late aftermoon, about 35deg c. last three days have had FI light on each time, C28 code (paperclip method) shows up.

I'm wondering whether these sensors are on the way out, or if high temp affects their voltage readings and signal to the ECM.

Thoughts ?

[BlueDragon]

I don't know about being temperature affected.

But when I had similar issues with the C28 code..  my 1400 would go several rides with everything fine - as in 400k plus in a day and no error code. this would have several stops along the way..

Then on some trips the code would come up within a few kays after each stop..

I eventually did all the checks and made adjustments.. but still had the same issue.  I ended up buying a complete second throttle body and just swapped in the replacement throttle body and no problems since.

Still have the original one sitting there as spare parts.. 

[Hooli]

They are engine temp related but as far as the fast idle for cold starts goes.

When the engine is cold the STVA turns backwards to control the fast idle. Then as the revs go up it does it's normal job of opening the secondary throttles. When dropping back to idle until warm it turns further backwards than normal to lift the revs again. It's normally only for 2mins or so from cold as far as I recall.

In your place I'd start by balancing the throttles then adjusting both TPs and SPS to the right values. I had a similar thing for ages but I seem to have fixed it finally with the new TPS I fitted. You can test the sensors with a multimeter but they don't always show as faulty unless they are really bad.

In my case I'd get the fault when accelerating slowly between about 90-100mph in 6th. It never happened any other time. I believe that's about the revs the ECU swaps from using the MAP sensor to the TPS as it's primary input to control fueling, I suspect if the TPS is giving a reading suggesting a different throttle position to the MAP sensor then it triggers this fault as it reaches that crossover

[Eric GSX1400K3]

Thanks Hooli, I need to check all three and balance tbs again.

It's just interesting that on the same ride at different temperatures it gives the error code.

The stva appears to be working, will check as per manual

[Hooli]

Aye the temp is an odd one, I think when mine played up it was worst in the cold. I can't think why though.

[grog]

TPS not temp controlled. Obviously the STPS is. My fast idle hardly works in Summer, 20 min. Does in Winter, 4-6 degrees. Dont understand why you need to balance TB s so often, mine never move. Do your adjusts Eric but id consider a reset, just touch batt leads together for a while. Solves a lot of probs with stuff i work with, i get this crap all day everyday. Just a thought. After leads together, turn ignition on, let it sit a while b4 starting. Common practice a lot of vehicles these days. Just trying to help.

[Hooli]

Dont understand why you need to balance TB s so often, mine never move.

Mine always falls out of balance between No2 & No3, it's probably a bit worn so the screw isn't gripped as tight as it should be. Hence I always rebalance before setting the TPS as with it reading off No1 to tell the ECU where No3 (which the cables move) is, it'll be wrong if the balance is out.

I probably should clean them up, dump a load of threadlock on the screw & then rebalance them before it dries. I've just never bothered. Similar to I did years ago on a MG where the mixture screws adjusted themselves all the time, I worked out the right place & threadlocked them so it never went out of adjustment.

[grog]

I agree totally Hooli, thread lock and should hardly ever go out again. I remember old cars, nissan Zs, Torana etc, 3 carbs on 6 cyl motors, so much mechanical linkage, set them up, one drive and stuffed again, just too much things to move. Old Ducatis were the best, watch one, finger in other, so easy. Old parallel twins, Triumph, Norton, Yam 650 etc. Trick was a cigarette paper under each slide, needed a helper. adjust until each paper slid out evenly. We were spoilt then, along came bloody 4 cyls, honda 750, Kawa 9s, had to learn to use gauges, same as now. 

[Hooli]

I've always just stood over my Bonnie & shut the throttle quick, if both sides click at the same time it's ok. Oh & the old pipe to the intake & held to my ear to see if they are sucking the same at idle which worked on my MG too.

[grog]

Agree again, so simple, whatever works.

[Hooli]

I always regard electronic control as cheating, proper mechanical stuff is real.

But I think we've taken this thread far enough off topic now?

[Eric GSX1400K3]

Thanks Hooli and Grog, I've only balanced them twice since buying the gauges, I had a discrepancy between 1-2 and 3-4.  Will check all electrical connections and make sure the battery is fully charged and reset as grog has suggested and report back.  Not sure when I'll get to it, I now have 3 other cars to look after as all three kids have now gone and bought their first car....