idle drop down

[jaylee]

find the end of the throttle cable

opposite it is the gizmo that supposed to push against it and raise revs when a/c comes on

on mine this was pushing out ,but was so far out of adjustment it only just hit the metal bit on its full extent

a little tweaking had it raising the revs as needed

In fact reading through this again... Wonkanoby sussed it for yah! But in your case it sounds like the the adjuster screw is pushing the cold start revs up too high, (sticking out too far.) so when it drops off your noticing it big time!? If i got that right??

the cold start engaged is at 950-975revs.
cold start off -750revs
dropdown to just under the line on dail at about 650revs!!!!! ticks over sweet.
sorry about the earlier 200-300 maybe a little over exaggerated

Personally I couldn't drive till warm enough with the choke out revving it like that.. (Manual or Auto.) (I call it a choke, i hope its the right term.?)

Lowering would achieve this?

Ady, this may or may not help...? http://www.igmaynard.co.uk/bongo/forum/ ... f+the+week

I know it refers to auto... & there may be a little change in engine stride when it drops out or kicks in, but my RPM stays at around the 750..

[dandywarhol]

I thought the left solenoid was to do with the EGR system and independent of the fast idle solenoid

The fast idle solenoid should work when the engine is cold (pulling the diaphragm rod) and when hot the a/c should very slightly raise the rpm, maybe 50 or so to compensate for the load caused by the compressor pump. i'm not aware of a further stage but if the rpm is too low then crank it up on the diaphragm adjuster til its right.

[Northern Bongolow]

thanks jamie and alan,im going away to twiddle.
alan both these two are connected to the pump,so both must affect it in some way.they do share a common vac supply with the egr solenoids though,so could affect each other but indirectly.
back soon

[dandywarhol]

Yeah, I knew the supply was common but thought they did separate jobs............

[jaylee]

They do Dandy... But on the cold start (choke) thing they seem to do the same job.. The one on the right a little longer than the left... Could be why the right hand solenoid thing with the white dot & connector burns out quicker?? Which was why i replaced my right hand with a used lefty!

[Northern Bongolow]

They do Dandy... But on the cold start (choke) thing they seem to do the same job.. The one on the right a little longer than the left... Could be why the right hand solenoid thing with the white dot & connector burns out quicker?? Which was why i replaced my right hand with a used lefty!

this may be the second drop down then eh! when the second drops out.
just been out for a twiddle and set the pump up as per your revs jamie,the good news is that the aircon pickup was miles out,set that independantly from the rest by disconecting the pipe work and set the throttle to the revs you said (750)and pushing the button that wonkanoby quoted.then put pipe back on the cold start/aircon pickup chamber thing,then set the revs on this.all this works fine now.but i cannot test cold start and the drop off till morning.
will let you know.
thanks so far guys i feel we are getting somewhere now.

[jaylee]

I could be wrong dude, there is no "second drop down".. On cold http://www.lushprojects.com/bongopartsmk2/1R29921.gif they cause 24-8002 to push, moving 24-173A holding the rpm to a respectable 750.. Then when up to temperature drops off, the engine carrys its own...

The AC thing is the same deal... Mine sort of cuts in idling in jams, at junctions..? You can hear it click holding the idle speed!!

As i'm given to understand this thread, your idle was just set too high when the solenoids activate... (I'm no way an expert!)

In the morning on cold start it will/should idle at 750, & by the time you get to the traffic lights & they ease off, the engine should run the same... Or as you said in an earlier post 650?? "Ticking over sweet!!!"

[Northern Bongolow]

yes i now understand what you were trying very hard to make me understand,kirsty has the same trouble,she tells me something 3 times before shouting it,then i get it
ive set the revs at 750,aircon on--still 750,thats good,it wasnt like that before.so in the morning when cold it should activate the cold start but still be at the magic 750 have i finally got it!!.

[jaylee]

I got to add a disclaimer... I'm not completely sure what i'm on about..

Post up tomorrow & let us know how ya got on!

[Northern Bongolow]

right!!!! as with your alarm thread the other day,sometimes the thing hits you when you walk away for a while.
well that and a lot of patience from the great people on this forum who will listen and not shoot you down when you come on here with some daft half arsed question .

all the following presumes that you have both solenoids working and ac that works.

if you set the tickover at say 750,when its cold the cold start acts like a choke and picks up the revs to 750,it does this by activating the right hand solenoid,this solenoid also sets the throttle to 750 when the air con is switched on as the added load pulls the engine revs/speed down,it does this by allowing the vacuum through the solenoid to the left hand side of the actuator pulling the linkage to the left thus increasing revs.
the problems start when the engine begins to warm,and less choke effect is needed to maintain the 750.this is when the left hand solenoid comes into play,as the speed of the engine is increased and monitored via the crank sensor the ecu operates the left hand sensor to open,this feeds the same actuator but into the middle area on the other side of the diaphragm inside it, but as they share the same vac supply a stalemate/equal vac is achieved on both sides and nothing moves!!. as the temps continue to rise the right hand solenoid turns off for a split second,then back on,causing the vacuum on the right hand side in the actuator to pull the linkage across slightly to the right,thus dropping the revs,temps rise a little more,then the right hand solenoid shuts again for a split second across it goes again until full shut off on both solenoids and the 750 is sustained by temps alone.
so the left solenoid is only used as a method to control the disengaging of the cold start.and smoothly maintain the said 750 revs.
this could explain why the right hand solenoid usually packs up working .because it does 3 or 4 times the work of the left hand one.maybe more if you use aircon regularly.
all the above is only a 04.00 theory so not proven,but wait until the neighbours waken and i will be out there testing.
thanks again to all who helped me understand this topic,

i hope this works in practice in the morning or im stuffed

[Northern Bongolow]

the above post is what happened when checked.
the full cold start is applied via the right hand solenoid.then as the warm up period progresses the left one switches on to create an opposing vacuum,then the right one switches off for a split second,drawing the diaphragm to the right (revs drop)as the warming up progresses more both solenoids switch off allowing the revs to drop off again.
so this allows a stepped drop off of the cold start and keeping the revs around the desired level 750revs in our case
it remains to be seen how many steps are observed in severe cold start conditions,but should in fact be the same number, as they must be engine temperature switched on and off,

[dandywarhol]

Mine always started around 900 when cold and dropped to 8/850 when warm (autobox)
If properly adjusted then the a/c should have little effect on the revs, as you say.

[jaylee]

What i cant work out is when the primary ignition plug warming is on that vacuum pump thing moves ready to start... (Auto diesel) 24-8002 http://www.lushprojects.com/bongopartsmk2/1R29921.gif
Now i know its the solenoid on the left that causes this primary movement, because the one on the right was shot at the time & i checked this out before i replaced it. (& during the busted solenoids removal.) & also switched the connector plugs & found a similar thing happened except the solenoid activated with the AC too?

This is the vacuum pump...? (Right at the bottom (2/2 with the hand pointing???) http://www.lushprojects.com/bongopartsm ... 1of02.html Whats causing the vacuum if the engine isn't running on plug warm up...? Or have i got it wrong???

The way mine is set up to start on cold mimics the tick-over full temp when up to temp & AC on a constant 750.. Works for me, like that when i got it!

[Northern Bongolow]

Mine always started around 900 when cold and dropped to 8/850 when warm (autobox)
If properly adjusted then the a/c should have little effect on the revs, as you say.

yes i agree with that alan,set the ac/fast idle to the warmed run speed and very little change will be noted.in reality its a good idea to set it 50-100 revs different as you said in your first post so you can hear it working, and you can let the engine warm up properly before driving off.

[Northern Bongolow]

What i cant work out is when the primary ignition plug warming is on that vacuum pump thing moves ready to start... (Auto diesel) 24-8002 http://www.lushprojects.com/bongopartsmk2/1R29921.gif
Now i know its the solenoid on the left that causes this primary movement, because the one on the right was shot at the time & i checked this out before i replaced it. (& during the busted solenoids removal.) & also switched the connector plugs & found a similar thing happened except the solenoid activated with the AC too?

This is the vacuum pump...? (Right at the bottom (2/2 with the hand pointing???) http://www.lushprojects.com/bongopartsm ... 1of02.html Whats causing the vacuum if the engine isn't running on plug warm up...? Or have i got it wrong???

The way mine is set up to start on cold mimics the tick-over full temp when up to temp & AC on a constant 750.. Works for me, like that when i got it!

jamie i think either you or i have our pipes crossed literally!! the right hand one should do the primary movement and the aircon,the left does the opposing pressure,well it does on mine.
dont really suppose it matters a lot,i will check under the wifes petty coat when i get chance to see which does what on hers.there are 3 different places where the pipes could be crossed over so .
the vacuum is stored i think from when it was last run, im going to try to test that,i will take the pipe off before attempting to start it up, it must be stored, then when the ignition is put on the solenoid opens to let the vac through to the chamber.

thanks guys for these replys,good to bat things about.