GREEN SCOOBY

As above lads and lasses, with pictures if possible, and how do you adjust if your having idle problems?

cheers

tweenierob

It may be that when you adjusted your Throttle cable you have messed up the Idle switch on the tps... How did you adjust it? was it by slackening off the two 12mm nuts on teh cable and tightening until there was no more slack?

If so... the first part of the movement on your TPS is the idle switch, if you have tightened the cable a bit too much the TPS will not return to the idle position and idle will be lumpy..

first cure would be to slacken off the cable slightly, or to adjust the TPS so that the new throttle position on idle is where teh idle switch is set..

TPS is located on the side of the throttle body, opposite side to the throttle linkage on the throttle body.. It has two small screws holding it in place.

Rob

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was it by slackening off the two 12mm nuts on teh cable and tightening until there was no more slack?


More or less mate, but not to the point that it was relly tight, there was still slack on the pedal. I did slacken it off later but do not know were it was originally.I will have a look at that tonight to see if anything is slack or moved. Cheers for that Tweenierob I will post back on here soon to update.

Dark Blue Mark

Rob, I dont believe the MY97 has a switch on the TPS? I asked this when I had the STi and was told it didn't. But too high or low a voltage may cause the ECU fuelling to fight what the TPS is saying, hence the bouncing revs.

Still bet on the o2.

MB

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Right lads! slight update. I have re-connected the lamda (it was off to see if there was any difference going to work today). I have backed off the throttle cable quite a bit and have re-set the ecu by disconnecting the battery for 2 hours and then let the car idle untill the fan kicked in twice.All the time the car was at idle the cars rpm was a steady 800 rpm.After the second fan kicked in I started to rev the car up to 3000 rpm and then watch were the needle stopped. It always went to around 1200 rpm and then down to 800 rpm everytime. I then done the ecu fault code check and the CEL flashed constantly with no breaks in it at all which means everything is ok (I done all of this the first time I was having problems and nothing has changed according to the ecu since then). I had a look for the throttle postion sensor and DID NOT TOUCH IT just incase I started this mess in the first place with the throttle cable. It looks to me that maybe it can be adjusted very very slightly (like the idle valve sensor) but you would need to take off the idle control valve to get to the bottom screw.Maybe not! So now I will have to see how it drives in the morning to see if anything has changed, I would do it know but I am on the piste. If there is no difference then the next step is as Mark has said, change the lamda. Fingers crossed. Thanks for your time Dark Blue Mark and Tweeniebob.

Roy

tweenierob

Just for info Mark, the UK 97 TPS and throttle body is different to the STI, 97 STi Ver3 has the phase 1.5 manifold, i am pretty sure the UK cars didnt go Phase 1.5 until 98...

R.

Dark Blue Mark

Agreed, but I was told the TPS is the same? I posted on 22b and there was a bit of debate. Either way I guess an over / undertightened cable will have the same effect.

MB

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Another update. Drove the car to work and back today and noticed more or less straight away the car seemed a lot better. When stuck in traffic the car nearly always stopped at 850 rpm. It is deffinately better than it has been for a good while. I am going to give it a couple of days to see whats what and if not 100% satisfied I will slacken off the throttle cable again and do another re-set. So now its got me thinking that Ive fcuked this thing up in the first place adjusting the throttle cable, but I am not getting too **** sure just incase it was a one off for today only. Thanks again everyone and I have everything crossed hopeing that the throttle cable was the problem.

Cheers

tweenierob

Sitting at work bored

<98 TPS has a switch and a wiper, if you listen when you move the throttle slightly from rest you can hear the click of the switch (first part of movement) the rest is just a normal 0.1-5v wiper..
98 TPS have one feed wire and two signal out, one reads 0.1-5v (approx) and the other reads 5v-0.1v. the ECU then uses both signals to work out where the Throttle Posision is (including idle)

<98 TPS is four wire, two idle switch wires and two wires for Throttle Pos
98 TPS has three wires only...

I have converted a couple of cars from <98 to 98 manifolds so i know a bit about the TPS's... The biggest PITA to sort out!

Rob

Just to add, this is why idle can be fecked up if you tighten the cable too much on early cars, the ECU switches to Idle mode when the TPS is on Idle.. If the switch is past this point it cannot switch onto idle mode...

Dark Blue Mark

Now I know, ta I do remember now that when I took it off it did click when moved - but never went back onto 22b to confirm it. Mine was an MY98 to confuse further

MB

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Right lads , another update! The car is still a lot better but not as it was before! It seems to drop down to around the 850-800 rpm mark all the time now, is this ok or am I being that little bit more paranoid as it never ever does the EXCACT rpm ALL the time but near enough? I have stopped on the road a couple of times to adjust the throttle cable to see what difference it makes and it seems that the slacker the cable the better the rpm are! So is it a case of

1. keep adjusting untill the rpm are ok?

2. keep adjusting and then an ecu re-set untill the rpm are ok?

3. adjust the throttle sensor? and how? to get back to normal?

Cheers

GREEN SCOOBY

bttt

tweenierob

Do not touch the TPS mate, i only ever adjust them when i need to change settings on ecu's.
To set the throttle cable correctly loosen off until you can just move the cable in between your fingers by the throttle body without the throttle mechanism moving.
You may find that finally tightening up the may take some slack out too, so make sure cable is ok with the nuts tight too.

RPM at idle sounds fine mate, just what i would expect... the Ecu has idle parameters, not that it must idle at exactly 870rpm(for example)

Rob

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cheers for that again tweenierob your a life saver. I would just like to thank tweenierob, Dark blue mark, Alyn at AS performance, Bob rawle, David from Api, The judge and everyone else who has helped with this problem. God I feel like I just won oscar.

GREEN SCOOBY

Another update. The car in traffic is now fine and idles around the 800-850 mark but I have noticed that when I come to a stop after a drive on the motorway the revs dive more to around the 700 rpm mark. Might this just be a case of adjusting the throttle cable till I get the whole thing correct?

cheers again.

tweenierob

It is just a heat thing, need to understand that the only adjustment you have on the throttle cable is to take the slack out, rather than adjust the idle That is a different subject altogether

Rob

Dark Blue Mark

Id be happy with that, ive never owned one that had a rock steady idle

MB

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cheers again lads, I should call you the dynamic duo? or terrible twins? ha ha lol.