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Discussion Starter · #1 ·
For f**** sake!! :banghead:

After reading up on the forums about alloy TB's etc, I've bought and fitted a new alloy TB to cure the high idle problems - idle sticking at up to 3000rpm blip the throttle, returns to normal - but it's WORSE! :confused:

It's a 97 216Si with only 38K miles. All the hoses are in good nick, no leaks.

What will be the benfit/effect of;

1. Disconnecting the battery to 'reset' (?!) the ECM;

2. Removing and cleaning the Idle Air Control Valve?

I don't want to spend load of £££ at a stealer for a new ECM, but is this the only way?

Help me fellas, what say you?
 
G

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I believe that about £40 will get it set up properly by the dealer - there was a thread on here some time ago explaining that just a new TB will not always do the job.
 

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i experianced probs with mine too, when its idling (after bliping the throttle) whats the RPM?? 1000, 1100?? if so, adjust the idle screw, knock it down to 950rpm +/- 50, this sorted mine out, but may be more of a setup procedure as Richard says.
Worth a try.

Ben
 

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mg_zr
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Don't you have to reset the "stepper-motor"...
Something like turn the Key to Pos I (or II) and press the accelerator 10 times....
 

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..shouldn't have to reset the stepper motor, but its worth a try i guess..

Sounds to me like the accelerator cable is sticking - make sure its adjusted correctly (i.e. a bit of slack) and that its not catching.
 

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mg_zr
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I presume if you've got the new throttle body, you've checked to make sure you don't need a new accelerator cable to match?
 

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Discussion Starter · #9 ·
Thanks for helping out lads (and lasses?)

Throttle cable is fine. I can get the engine to repeat the same fast idle by blipping the throttle cam on the side of the TB. Returns to normal position but engine keeps revving.

The TB (48mm) came with a new TPS (throttle position sensor) already attached. I have done the re-set the stepper procedure, not that I think it has a stepper - 16v K series 1.6 i, it has an IACV Idle Air Control Valve instead. Can anyone tell me otherwise and if the 5 times and do-si-do your partner makes any difference to the IACV?
 
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cosb6 said:
I presume if you've got the new throttle body, you've checked to make sure you don't need a new accelerator cable to match?
only applies when upgrading derated (85bhp?) 1.4 models.
 

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Discussion Starter · #12 ·
Brown & Gammons - legends

Took it to B & G's for a proper set up.

After a spell on the testbook, they discovered that the coolant temperature sensor was faulty. Replace that, clear the faults, reset the stepper, adjust new TB throttle stop screw & ECU reset. All fine & purring like a kitten!:cloud9:

The temp sensor probably went when the HG failed and lost all the coolant - beware.
 

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Good news Jon - money well spent as that coolant sensor would have been costing you in terms of wasted fuel.
 

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Discussion Starter · #15 ·
Well, no, actually, it still went from cold to hot, but it failed the testbook check and was replaced.

As for the high idle, it's come back. :(

I got back to B & Gs and the technician said that the TB was sticking but they had lubed it and reset the stepper and all was well on the test book. Perhaps out the plastic one back on, they said...

So, head back under the bonnet and I had a closer look with the airbox hose off. Not apparently sticking, until, upon closer inspection.... well f*** my old boots! My brand spanking new ALLOY TB was sticking! When being gentle with the throttle, the butterfly doesn't return to fully closed and the engine revs up. Snap the throttle hard and it springs back properly.

So lube it I will (it's dark now) and we''ll see. Maybe the spring isn't up to the job.

Major I, I remember seeing on another thread your post "a turn of the nut on the TB works wonders". Tighten or loosen?

If the TB is faulty, how likely am I to get a replacement now it's been fitted to the car?
 

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Discussion Starter · #16 ·
Getting to grips with it...

So, head under bonnet again....

Remove & lube the TB - WD40 inside & out. Bit better? Not really.:shake:

Seems that the butterfly fits in the TB aperature so snugly that it can stick in and it needs a bit of extra pressure to get it moving. On the other hand, I find that the tight fit of the butterfly meant that it wouldn't slot back into the fully closed position that the throttle position sensor recognised as closed. Tried the old TPS from the plastic TB. No difference.

:wtf:

So, a few test runs later and accurate adjustment of the T25 idle screw & locknut on the TB, so that the butterfly can't return back to the stuck-in-the-hole position but is still closed...then remember to reset the TPS closed position (Ignition position II, five times down & up on the throttle, 10 secs then ignition off)...and things seem a bit better. :err:

There might be a bit more adjustment to do, as the revs don't quickly return to 900rpm tickover, but it's an improvement as they don't get stuck at 2000rpm anymore. A few days testing and fettling then I'll get back to you.
 

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Discussion Starter · #17 ·
Ran like a dream all day today

Seems that's it sorted. It ran like it should all day today. Returned to 900rpm idle at every junction. Revs matched speed, nice and smooth gear changes. Now perhaps I can enjoy the brighter side of Rover ownership.....

:s2h:

Cheers for everyone who posted help and advice.
 
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