Idling problem.!!

[raj]

as ive got the car up and running now ive had the chance to give it a once over.

ive notice the idle is slightly irregular! it wont sit a one certain point. the revs will rise and fall slightly.

take note that none of the boost pipes are fitted,and one of the oneway valve ports is blocked off with a bolt and copper washer.
im thinking i may possibly have a leak somewhere?
ive noticed that when i pump the brake pedal the idle gets VERY irratic.

previously when i was carrying out other work i came to notice that the new one way valve on the back of the inlet manifold was stuck open, ie i could simply blow through both ends!
after poking a small screw driver down it the valve became unstuck.
could this be the cause of the irattic idling if its managed to stick open again?
also why would the one way valve stick? its a new valve and washer.

[Chris Hebden]

This could well be your problem mate. Have you WD40 it?

[dgdogz]

i have the same sort of problem
when i start the car its all good and dandy take the choke off and all is well
then it will go pretty high and then all of a sudden usually when the car is up to temp and the rad fan kicks in it usually evens itself out and wioll stay like that for the rest of my drive??
any ideas on this?
sorry for the thread jacking but i supose its sort of related

:)

[raj]

This could well be your problem mate. Have you WD40 it?

no i havent 40'd it. will wip it off and do that and see how it goes.

also to add, the car is a right b1tch to start from cold, i have to keep cranking the engine over a fair few times before it slowly coughs into life! hopefully its related to irratic idle problem?

[raj]

firstly -> is it normal for the revs to drop if you keep on pumping the brake pedal.?

my revs drop when i keep doing this, the quicker i pump the pedal the more the engine starts to splutter. however it does seem ok if i apply the brake pedal as you would in a driving situation.


ive checked for any vac leaks and everything seems to be leak free.



ive also taken the new oneway valve off to see if it was stuck open..it wasnt!
i also compared it with a few others i have. the new one feels kind of more harder to blow through compared with the other older ones! im just assuming thats due to it being new,right?



i also sucked on the servo pipe to see if i could actually suck air past the servo.. i think i can only suck what air is actually in the pipe as if i put my lip over the pipe after sucking it wants to pull my lip down the pipe. i recall scoff telling me if i could suck air up the pipe the servo is buggered.

[UNICRONICUS]

It is normal for the revs to drop when you pump the brake pedal, and it will splutter if you press it repeatedly. I would point my finger towards the carb but looking at your last thread with regards to idling I would have said your carb was fine...

[Tiny Tim]

Vacuum leak or cack earth. Dont forget with your foot on the brake pedal the brake lights will be on, putting extra strain on the alternator.

[raj]

yes the carb is fine:agree:

i cant find any vac leaks:scratch: theres not really alot of places it could be leaking from anyway! to add,ive done away with a few hoses [cupmod]. ive checked on all areas.

as for putting strain on the alternator, would this happen even if the alternator And battery is new.?

all 3 earth points- bulkhead,front of engine and batt neg are all in check:agree:


the thing is, am i worrying about nothing as im not sure if rapidly pumping the brake pedal would cause the revs to drop even if everything is in check..?:scratch:

[Tiny Tim]

Well as the servo works off the vacuum I wouldnt worry too much - so long as your brakes work fine.

[Chris Hebden]

the thing is, am i worrying about nothing as im not sure if rapidly pumping the brake pedal would cause the revs to drop even if everything is in check..?:scratch:

Raj just been out to see what mine does, and from warm the idle does jump about when i press the brake pedal repeatadly. As Tim says if the brakes are fine and you've got a hard pedal before you start the engine and when you start the engine the pedal drops slightly, with pressure on, then things would seem to be working as they should.

I'm sure the master wrote somewhere a great way of checking vaccum and pedal movement.......................

[raj]

if the brakes are fine and you've got a hard pedal before you start the engine and when you start the engine the pedal drops slightly, with pressure on, then things would seem to be working as they should.

I'm sure the master wrote somewhere a great way of checking vaccum and pedal movement.......................

as you describe above is how my car is acting, so ill just take it as me worrying about nothing as usual:ashamed:

ill try and find this guide?that the master has done:agree: