Technical Handbrake switch and struggling idling...

[littlephil]

right 2 things.

Took the x out for a run last night, got it in the upper rev range (5000+) to show my lovely missus she wasn't over revving and when it came down to stop for a red light it wouldn't idle. could the choke have opened because of the vibration? mucky jets? shouldn't be the ignition because its electronic.

and where the hell is the handbrake warning switch? how do i get to it?

cheers

 

[jimbro1000]

**** In Jets - you've opened it up, got the fuel flow going and the pump sucking up **** from the tank which then gets pumped straight into the carb. You need lots of carb cleaner and plenty of patience. It sounds like the idle jets are the problem or worse still the progression feeds which is going to make it hard to do.

In terms of prevention - you need new fuel lines between the tank and the carb and a decent fuel filter to collect the crap that does get picked up.

 

[littlephil]

thought it might be crap in the carb. just started it this morning and its fine but its idling a bit lower than usual (usual is about 1000rpm, its now ticking over at about 800rpm.) I think i can manage that, done ones on my vespa before...numerous times ;-)

Do you know anything about the handbrake light switch??

 

[ChrisPR]

I think it's literally right underneath the handbrake handle - if you can take the gaitor off you should see it. Usually a white plastic 'button', similar to the one in the door jamb (that controls the courtesy light).

edit : Just found a photo of it - there's a special bracket (on my 1500 at least) that sits towards the front of the handbrake lever and raises the switch up to the underside of the handbrake.

 

[ChrisPR]

Hopefully the image should be attached below ...

 

[littlephil]

ok, carbs clean and running very sweetly should i rejet for the csc exhaust? its the manifold to tail pipe job?

and i've sorted the bad earth on the handbrake switch, i've never come across this before but when the handbrake is on the warning light flashes is this normal in an X? when the brake fluid is low it stays on solidly.

 

[jimbro1000]

I always thought that the flash on the handbrake light was the other way around. Flash for low brake fluid or on solid for handbrake.

Traditionally the CSC system was sold with replacement jets but from personal experience the jets didn't make much difference as sold. It took a rolling road session to get it properly right but I did have a number of other mods too.

 

[littlephil]

right, its still happening. If you rev the car up past 5000 it cuts out until you dip the clutch then it struggles and dies. On restart it idles but wont rev properly. but give it 20 minutes its fine again.

Could it be the coil?

 

[jimbro1000]

The worrying bit is that it takes 20 minutes to recover.

Typically this would indicate an overheating problem but why it should manifest itself only after revving past 5000 is rather odd.

If you haven't done so already you need to go back to basics and check things over one-by-one and make sure you test the car after each one.

I'm sure I can come up with some more but these are the things that spring to mind:

1) The cam timing is off, once you get to 5000rpm the poor breathing makes the engine struggle and the fuel supply fails due to lack of air flow. Removing the load (ie dipping the clutch) should allow it to recover pretty much immediately.

2) The fuel has a partial blockage probably based around the secondary circuit. Again the car should recover once the load is removed as the primary circuit should more than sufficient to cover the fuel supply requirement.

3) The engine has a major air leak, this could be anything from the manifold to the head or block. A compression test on a hot engine should show if it is within the main block assembly.

4) The oil pump is not providing enough pressure, you should see warning lights and a low reading on the gauge if it is - this would result in the engine overheating. It is possible that one or more of the oil pathways is coked up and the oil supply is inadequate for high revs. This would not show on the gauge or warning light - only an examination of the bearings would give a real indication. The engine would massively lose power as it is trying to sieze up when hot and revving hard and it would take time to recover.

5) The igntion system is suffering a major failure, the distributor advance could be off, the coil could be on its last legs, etc. Only replacing the individual items one at a time will give you the answer unless you have a proper diagnostics machine.

6) The water pump is not working to spec so it over heats under load, this could also be the radiator blocked internally so the cooling capacity is reduced.

 

[littlephil]

hi jimbo

its not recovering immediatly, when it throws its hissy fit i can usually get it home but i'm working the throttle and got to keep it above 3000rpm and play with it. but like i say, give it 20 minutes and its fine again... thought i'd give it a blast down the M6 and it spat its dummy out coming back home just after the bridge (junction before irlam) but i got it off the m/way, waited and its was fine at 70 all the way home. but it cut out just driving at 30 in 4th (2000rpm) yesterday, after it stopped i fired it up again and it was fine instantly.

right i pulled the plugs and they are all evenly a lovely colour of coppery brown. so i don't suspect an air leak.

i don't have any oil pressure problems showing (lights. gauge etc.) and the car isn't overheating at all, but i am having problems with the internal heater.

i'ts fitted with a bosch electronic ignition? but looking at the paperwork i've got they didn't replace the coil. i think i'll give that a go first...

if you can think of anything else?

 

[jimbro1000]

If you want you can bring it over to me for a look - I don't have all the tools here but I can certainly take a look

 

[rachaeljf]

Make sure the fuel tank vent is not blocked. It consists of a little bit of plastic pipe coming off the filler neck, with a little ball valve like a snorkel. The valve is supposed to let air in while the car runs and the fuel level goes down, but blocks fumes coming out while the car is standing. If the ball jams shut with dirt, the fuel pump draws fuel as you drive and a vacuum builds up in the tank. Eventually the pump can't draw any more fuel against the vacuum and the engine dies. If you let it stand for a while, air leaks back into the system and the engine recovers.

To test for this problem, try driving with the fuel filler cap off and see if your troubles go away.

Cheers R

 

[littlephil]

right this is what i've done...

stripped and cleaned the carb, inspected and cleaned the dizzy and coil contacts (the coil was red hot!)

fitted a new internal heater matrix and it still doesn't work, the engine isn't getting hot (about 1/4 on the guage) so i think i need a new thermostat


took it for its weekly belly and arches jet wash and it did it again. i didn't rev it this time it just cut out and was a swine to get home again. I don't think its heatseizing because it doesn't feel like it, it just feels like something either died or is blocked. the thing that is concerning me is the coil is getting really hot. Also when i am driving it like this if you get the revs up its not bad (just going like a bat out of hell) but your foot is planted to the floor at 2000rpm in 3rd and there is nothing at all and if you let off it dies.

what can it be?????

 

[bludvl_x19]

My suggestion is to check the fuel mix screws between the two throttle throats. Possibility that one of them is loose.

 

[littlephil]

hamdula! it revs like a sportsbike and pulls like a train now. I ran it for a couple of minutes with the main jet and mixer tube out.

but now its over cooling :-( so where on the engine is the thermostat housing? what should i be wary of when replacing the thermostat?