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Hello,

I have a 1997 T595 with @ 30k miles on (I have only done @500 miles since buying it 2/3 years ago as the tick-over is high, @ 1750 rpm. When I bought it I assumed it was a simple screw to turn the tick over down - how little did I know, how much have I learnt!

I have trawled the internet for hours reading all the info I can find, without success.... I have changed all the fuel filters and pipes in the tank. I have changed the throttle body gasket.
I have used TUNE ECU and I can see that the bike has a target of 1200 rpm but I am unable to get it to tick over at this. I have obtained and tried a second hand ECU with the same result, I have tried various sensors being replaced - same result. There is free play in the throttle cable. I have resent the TPS (throttle position sensor). The only time I got the required tick over (after pinching myself) I discovered that I hadn't reconnected the engine temperature sensor (by the radiator cap group of hoses that sits in front of the tank..) when I put it back on I was back to square one....
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I did read that the engine should stall if you take the pipe from the air box off the idle valve and put your finger over it. Mine doesn't so I think the problem is between there and the engine.
I have removed the pipes from the idle valve to the throttle bodies and tested them and am convinced that they do not leak (from their condition I believe that they are not the original ones).
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Within the history of the bike is a comment from a garage that balanced the throttle bodies which has resulted in a high tick-over.... So I believe that there lies the problem
I did take the bike to an authorised Triumph dealer (I wont name them - but suffice to say I wont take the bike back - as they said it is good for "one of those" but you could spend lots of money and be no better off - just ride it. And suggested I take it without them doing anything - so I did). The problem is, I believe that the high tick-over means it runs hot and will not run low rpm in a high gear. (3rd gear for a 30 mph limit....?) It certainly shifts when you go up the revs but low down it is crap! Hence I have not gone and used it, but want it to be right (I am a bit anal like that - make it right or don't bother!)

I have bought a Morgan Carbtune kit to try and balance the throttle bodies. I can get the revs down to about 1300 but only if the balance is so far out it is untrue. With the bodies balanced it it ticking over at @ 1600/1700 rpm. This is with the carbtune attached. If I take it off and connect the correct hoses from the idle valve the engine still ticks over at this speed...

I did notice when I was cleaning the throttle bodies, that with the throttle closed, shining a torch from the engine end, you could see quite a bit of light between the edges of the butterfly valve and the inside of the chamber. Should it not be airtight. I have tried to get the engine to tick over and blanked the air intake but the engine dies. I understood that the air for the tick over is supplied by these hoses from the idle valve. Am I missing something basic? I did not play with the stop that is attached to the throttle bodies - the Triumph dealer said they are set by the factory and never to touch it....

Is it the idle valve / stepper motor that is faulty (if so why is the tick over high when it is disconnected and the carbtune system attached)?


Help???

I keep trying and trying to adjust the throttle bodies but cant get any synchronisation with a low tick over.... (Just pi**ed of neighbours as it has a loud pipe on!)

Do I need a new (second hand) throttle body. Do I need a new idle valve and housing.

Any and all suggestions welcome.... Or even if anyone can recommend a good garage that can resolve this matter that isn't too far away, I am prepared to travel!

Thanks in advance,
Stephen

PS I think I cured the running hot by continual flushing of the radiator and engine block and renewal of coolant.
 

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Wow. You've tried a lot. The only thing that occurs to me is that my bike has the same high tick over when cold. It doesn't worry me at all because as soon as the engine gets some heat into it, the tick over comes down. So if your temp sensor has failed, or the wiring to it is broken, the EMU will think it is cold and so keep tick over high.

TuneECU should tell you what the computer is getting from the sensor.

As for town speeds being tricky, you could change the gearing anyway. I feel my 2003 is over geared so trickling in town traffic in first gear is a pain. Ive been thinking about going down a tooth on the gearbox sprocket.

Your bike will run right in the end :)
 

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Just a quick one for now, will reply with more detail later
The idle air is actually a combination of air past very slightly open Throttles AND IACV air - the balancing process is actually adjusting the angle position of two of plates to allow more (or less) air so that the total of both iacv & throttle together is the same for each cylinder. By that definition alone then the throttles cannot be fully closed
Sometimes a leak at the tb/head gasket can cause this problem and you could certainly try spraying some alcohol or other around that to see if rate is altered.
It does really sound like your throttles are too far open however - if you can block the iacv intake and it doesnt stall then it kinda suggests the throttles are too far open (although blocking intake does not dismiss possibility of leak at hoses or the iacv manifold)
As I was typing above, one thing to consider is that your hose config on the iacv manifold is correct and that you have no open ports on that - I have a picture that shows correct that I will post later
For the throttles- One is not adjustable and the problem may be related to that - the 'closed' position may not indeed be correct off the throttle stop & from there you just cant get the other two matched to it without all being seriously too far open
So I suggest focusing on the 'fixed' one first
i.e. adjust the stop position

One other problem on these older TBs is the o-ring on the TPS can cause the throttle to hang - if I recall correctly that o-ring isnt really sealing anything & can be removed

Re LeT comment about running high when cold, that is intentional as set by table in the map.
So of course engine needs to be at normal temp when adjusting

Hope some of those ideas help! Good Luck!
 

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Discussion Starter #4
I have tested the engine temperature sensor. It was within limits on the ohm meter and Tune ECU shows the engine temperature, the gauge rises and the fan steps in as appropriate.... I am as confident as I can be that is not the problem - but I am beginning to doubt myself
 

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How are you connecting the balance gauge? I connect direct to the bypass ports, remove the iacv hoses - now first thing is it should typically not run like this since you have no air coming through those bypass ports - if it does run it already suggests too much air past the throttles; normally you have actually put a shim in the stop to get them open slightly where you can have it run & balance
 

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Discussion Starter #6
How are you connecting the balance gauge? I connect direct to the bypass ports, remove the iacv hoses - now first thing is it should typically not run like this since you have no air coming through those bypass ports - if it does run it already suggests too much air past the throttles; normally you have actually put a shim in the stop to get them open slightly where you can have it run & balance
When warm. Took iacv hoses off, connected the gauge and it fired up and races away......
 

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Thank you. The next day I get to sort this out at least I know where to look / what to adjust... Is there any way to measure the correct clearance of butterfly/throttle body inner clearance (feeler gauge etc)... How do I know what reading I should aim for on the carb tune (apart from just getting them all to read the same)..
 

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I read that you changed the TB gasket. One tip is to loosen the bolts between the TB before placing them back onto the head for a secure seating on the gasket. Then, tighten up everything. Maybe you have a small leak if you didn't do this.
 

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Discussion Starter #10
Looks like plan a is throttle body off. Check tick over stop and adjust so closed throttle is closed a touch more. Then new gasket and refit bodies.. therefore I will use this tip. Thanks
 

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So balance is balance whether at 1800 rpm or 1200 rpm
I would say get it balanced, even if it's running fast & THEN adjust your throttle stop so your idle speed comes into control - note that you will still want a bit of area to allow the IACV to do its job (and you can tell that it is by again doing the blocking of the IACV intake trick and it should stall or come close to it - it speed does not at least drop when you block the port, it means that it is still pulling all its air past the throttles and you will need to close them some more)
 
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