Mk1 Nexus buyers guide?

[Taipan]

I'll find out Saturday! I'll take the TB out tomorrow so its all ready for your one when I get back Saturday!

[TmaX9]

OK BenR, you take it from here. No more bullshit from me, you can all sort out your own problems from now on.

[Taipan]

Well I've removed the throttle body. Once I had the throttle cables disconnected I could plug it in and turn the ignition on/off and see if there was any movement from the stepper motor. I cant see anything moving so it'll be interesting to see when I connect the new one later on today if its any different?

I did film it with my phone camera but I didnt realise there was no light getting into where the stepper motor is. So you cant that there is nothing happening but then even if you could see it, there is nothing happening anyway!
" onclick="window.open(this.href);return false;

[Taipan]

Well I fitted the new Throttle body and it worked fine. Idle is slightly lower at just on the 1500 but its steady. Main thing is the bike is now a lot more rideable as it doesn't cut out when you come to a stop. Seems a bit better on pick up too but maybe thats just me thinking it is. So all in all a worthwhile exercise. Thanks to Ben for the tb and good to meet you too mate.

Only disappointment is the EML is still on and its still popping on the overrun on a trailing throttle. I did notice it is blowing slightly at the exhaust joint too so that wont help but I dont think that would cause my EML light to come on.

My next move will be to fix the exhaust blow and fit the coupling pipe when it gets here and then get it into Scootech or GLRs for a scan of the diagnostics and see if they can reveal anything. This is a bit of a pain as I'm not near to any of them so it means walking the streets looking for a cafe until they've done it, or maybe they'll scan it while i wait?

So I'm really pleased to have cured the cutting out, but a bit disappointed I wasn't able to fix the popping on the overrun/EML light issue as I hate being beat. Oh well onwards and downwards!

[michaelphillips]

glad to here you have stopped the stalling, well done mate, yes you need to sort that exhaust leak, as this could stop your popping, (as when they take the baffles out, and unrestricted flow, will cause popping) idle is correct at 1500 + or - 50rpm
when you take the exhaust off, internally there should be a gasket seal as below:


as the clamp wont be sufficient on its own to seal.... sometimes they slip too far in to silencer.. if not there you could use exhaust wadding also check the air filter and the box it sits in as this could have a hole in it....
On all the troubleshooting tips, page 209 of workshop manual, the revolution timing sensor also pops up as probable cause in all the troubleshooting, you will have to look in the workshop manual, it is bolted in on the exhaust side of the cylinder head, but this will be thrown up on the tester when you have it taken in....
the tester would be a good idea, as it could be a few things - injector- valve timing or worn valve seals - possible head gasket leak - etc
best thing would be to do the exhaust sealing,

[michaelphillips]

it could also be the valves are fouled up with all the dirty air getting in, and the injector also dirty, it has an 80 degree spray to the two intake valves. Also if the timing is out, the exhaust valve timing could still have the exhaust valves slightly open when they are supposed to be shut, or they have a build up of carbon on them and not seating fully...... i know generally our fuel these days mean you dont have to buy additives,,, yet in your case i would use http://www.halfords.com/webapp/wcs/stor ... yId_255221" onclick="window.open(this.href);return false;
mainly to clean the injector, your fuel pump assembly in tank and the intake valves, i do use this once a year as the age and mileage of my scoot i think it does keep things clean, i use 30ml to £7 fuel
you could also use Wynn's Hydraulic Valve Lifter 350ml http://www.halfords.com/webapp/wcs/stor ... yId_255221" onclick="window.open(this.href);return false;
not sure when your last oil change was, and how often in past was done, but the valve lifters could be sticking, or sticky tappets... causing the exhaust ports to be open ,,, they only have various detergents and viscosity improvers in it and it only has to weaken the crud the pressure will do the rest. you add it to the engine oil, then run it, just a few thoughts

[BenR]

Well I fitted the new Throttle body and it worked fine. Idle is slightly lower at just on the 1500 but its steady. Main thing is the bike is now a lot more rideable as it doesn't cut out when you come to a stop. Seems a bit better on pick up too but maybe thats just me thinking it is. So all in all a worthwhile exercise. Thanks to Ben for the tb and good to meet you too mate.

Only disappointment is the EML is still on and its still popping on the overrun on a trailing throttle. I did notice it is blowing slightly at the exhaust joint too so that wont help but I dont think that would cause my EML light to come on.

My next move will be to fix the exhaust blow and fit the coupling pipe when it gets here and then get it into Scootech or GLRs for a scan of the diagnostics and see if they can reveal anything. This is a bit of a pain as I'm not near to any of them so it means walking the streets looking for a cafe until they've done it, or maybe they'll scan it while i wait?

So I'm really pleased to have cured the cutting out, but a bit disappointed I wasn't able to fix the popping on the overrun/EML light issue as I hate being beat. Oh well onwards and downwards!

Good to meet you too, I'm certainly glad it worked. If you do got to see Steve at GLR give me a shout, although I'm there most Saturdays anyway, you're more than welcome to pop round for a cuppa.

[BenR]

OK BenR, you take it from here. No more bullshit from me, you can all sort out your own problems from now on.

Hi Dave? My post was a bit blunt I didn't realise it was you who made the original post I'm very sorry if I've offended you. However the TBs on the master engines have no chip set so there's nothing to code them to the ECU. On the early ones (like mine) they don't even have a TPS or automatic compression release valve so the ECU doesn't actually run much just the dash & injector although I'm sure you know this already.

[Taipan]

it could also be the valves are fouled up with all the dirty air getting in, and the injector also dirty, it has an 80 degree spray to the two intake valves. Also if the timing is out, the exhaust valve timing could still have the exhaust valves slightly open when they are supposed to be shut, or they have a build up of carbon on them and not seating fully...... i know generally our fuel these days mean you dont have to buy additives,,, yet in your case i would use http://www.halfords.com/webapp/wcs/stor ... yId_255221" onclick="window.open(this.href);return false;
mainly to clean the injector, your fuel pump assembly in tank and the intake valves, i do use this once a year as the age and mileage of my scoot i think it does keep things clean, i use 30ml to £7 fuel
you could also use Wynn's Hydraulic Valve Lifter 350ml http://www.halfords.com/webapp/wcs/stor ... yId_255221" onclick="window.open(this.href);return false;
not sure when your last oil change was, and how often in past was done, but the valve lifters could be sticking, or sticky tappets... causing the exhaust ports to be open ,,, they only have various detergents and viscosity improvers in it and it only has to weaken the crud the pressure will do the rest. you add it to the engine oil, then run it, just a few thoughts

The TB I got form Ben has the inlet manifold and injector too, which are from a much lower mileage bike. So perhaps I should swap them over anyway. Its only 3 bolt but I suspect there's a lot of other stuff that needs removing to get at it? Sadly I wont have time today as we're off out this afternoon. So I'll do that next weekend as hopefully the inlet coupling will be here by then as well.

The oil has been changed religiously. The bike has a very comprehensive service history. Its had a new fuel pump too (£180!).

I'm going to have a uick look at the exhaust to see if I can fix that but suspect that's all the time I'll have to work on the bike today. Bloody social occasions messing up my spannering time! ;D

[michaelphillips]

Quote:
The TB I got form Ben has the inlet manifold and injector too, which are from a much lower mileage bike. So perhaps I should swap them over anyway.
i would not bother swapping them over as extra work and as long as inlet manifold is tight and not leaking, extra work to fit and pipes for injector, the inlet valves may be clogged up, with the dirty air getting in, http://www.halfords.com/webapp/wcs/stor" onclick="window.open(this.href);return false; ... yId_255221
mainly to clean the injector, and the intake valves, or i suppose treat your scoot to the more expensive unleaded shell fuel, as this would have the same cleaning effect, yep the exhaust needs a good seal, back compression and pressure required, have a good family day,