Hi
I have an annoying problem.
When i'm braking, my car tries to stall (Yes i have the clutch in :P)
As soon as i come to a complete stop the idle smoothes out again. But i find when i'm braking i have to keep blipping the throttle to keep the engine running.
I was thinking this might be incorrect float level in the carbie(s)? Would i be right?
[ Edited on 18-9-2007 by jo_tas ]
VWCOOL ·
yeah sounds feasible. May also be a loose intake manifold that 'leans forward' when braking, letting in air...?
Bizarre ·
jo_tas wrote:I was thinking this might be incorrect float level in the carbie(s)? Would i be right?
Not if it just started doing it.
Float levels dont "just" change.
What happens when you are idling and put your foot on the brake??
What happens if you accelerate and ride the brake??
Barry
jo_tas ·
Bizarre wrote:
jo_tas wrote:I was thinking this might be incorrect float level in the carbie(s)? Would i be right?
Not if it just started doing it.
Float levels dont "just" change.
What happens when you are idling and put your foot on the brake??
What happens if you accelerate and ride the brake??
Barry
How could the brakes affect the idle??
Idle doesn't change when i put my foot on the brake.
Haven't tried having my foot on the brake when accelerating.. but what would this prove?
rob53 ·
Maybe the carb is running a bit lean? Maybe try increase the fuel mixture to see if that remedies it.
geodon ·
Braking while in gear generates the highest possible vacuum in the intake system.
Think: throttle shut, wheels keep turning the motor at faster speeds than idle ie keeps sucking against a closed throttle butterfly so UP goes the vacuum.
If there is a leak, it will be magnified big time ie far more air than the idle mix requires so the mix leans out= stalling.
To diagnose this scenario, try putting it in neutral then brake.
[ Edited on 18-9-2007 by geodon ]
greedy53 ·
dam ya good
Bizarre ·
Was thinking it might be electrical
jo_tas ·
geodon wrote:Braking while in gear generates the highest possible vacuum in the intake system.
Think: throttle shut, wheels keep turning the motor at faster speeds than idle ie keeps sucking against a closed throttle butterfly so UP goes the vacuum.
If there is a leak, it will be magnified big time ie far more air than the idle mix requires so the mix leans out= stalling.
To diagnose this scenario, try putting it in neutral then brake.
[ Edited on 18-9-2007 by geodon ]
interesting.. i'll give this a go today..
jo_tas ·
Tried braking with the car in neutral.. still stalls. I'm gonna try enriching the idle mixture a bit tommorow.
vw54 ·
Jo
Have you checked all the engine mounts to see if there sound front and rear
when you brake the engine may be swaying or pulling and stretching the accelerator cable causeing the engine to stall
do you have the later model with the rear cross mount is the body fractured around the welds ???
Bizarre ·
Jo
Has it only juststarted doing it??
Grey 57 ·
I would try leaning it out a little too Jo. Test is to rev the motor up (in neutral and stopped with hand brake on) hold the revs at about 2500 or so then let the throttle off. If it stalls or trys to, then its mixture. Might even be a slightly blocked jet.
jo_tas ·
Yeah... its just gradually started doing it.. over the last month or so
mackaymanx ·
I had a similar problem in with my Manx(34PICT-3), it turned out to be a blocked jet in the carby.
Grey 57 ·
Jo, here is road side mechanics 1 0 1 on how to try and unblock a carburettor jet with out pulling the thing apart. Works some times if you are lucky.
Step 1 - remove air cleaner /s
Step 2 - start engine, out of gear , hand brake firmly on.
Step 3 - walk to back of car (rear engine, front for others) . Find throttle lever on carbie and push it open to rev the engine up a bit.
Step 4 - hold throttle lever open and with engine revving place your hand over the carburettor inlet. This will choke the engine causing it to suck really hard on your hand. Before the engine completely dies take your hand off the carbie inlet and allow it to recover and rev up again (you will still have the throttle lever open) and then block the carbie inlet again. Again before it dies take your hand off and repeat a couple more times. Then just let it idle to see if there has been any change.
If you are lucky,the strong suction created by blocking the carbie inlet,might have sucked the crap out that was blocking the jets.
If yes , replace the aircleaners and test drive. All good, then make a mental note to replace fuel filter and hoses sometime soon. Cause the crap tha blocked the jet came from some where.
Couple of words of caution.
- Dont overrev it. Just build up the revs to about 2500 and block the carbie.
- if its an auto. make sure its in Park and Hand Brake is on real hard.
- if your Type 3 is a twin carb model you will need some help to block both off.
- Keep engine bay clear of nuts and bolts and spanners when you have the air cleaners off. You dont want stuff dropping into your carbies when you are doing this.
Adsman ·
Also found that the butt end of a screwdriver tapped on carby while under revs works well too.
Joel ·
turning the screwdriver around and removing the jet works even better :P
u can see what has actually blocked it
i agree jo, does sound like one not both idle jet is blocked
vwtyp2 ·
have you got an aftermarket vacuum brake booster fitted?
jo_tas ·
vwtyp2 wrote:have you got an aftermarket vacuum brake booster fitted?
Nope.
I'll look into the blocked idle jet theroy...
vw54 ·
may be shit in the carby
greedy53 ·
tryed that didn't work
jo_tas ·
greedy53 wrote:tryed that didn't work
Wha?
No, i haven't tried it yet..
Grey 57 ·
vw54 wrote:may be shit in the carby
with the motor running or stopped!!!:P:P🤪
stevosky ·
Check that some of the little rubber caps on the carby haven't got splits in them and sucking air through them. They deteriate after time.
jo_tas ·
Just finishing off this topic by saying it was running too lean at idle. Turned the screws out about 1 turn and runs like a dream! :kiss