Bongo Fury

has anyone else noticed this.After cold start the bongo warms up and the fast idle drops off.Drive a few miles and the bongo is up to normal running temps.Come to a set of trafic lights on red,if the bongo sits there for a couple of mins the revs drop off slightly(500revs).
my question is, is this normal,is it an early form of the audi stop start system to avoid pollution.there has been some discussion about the operation of the left hand relay mounted on the glow plug rail mount next to the fast idle relay,is this the control for this as it connects to the pump air control diaphragm.Any thoughts, please note that mine is a 2.5 diesel manual,so i dont sit with it in gear at the lights with load on the engine unlike an auto left in D which has load left on it when waiting to drive off.I suppose you may notice it if you start an auto and leave it to warm up itself.

From cold start I can feel mine drop down once the needle reaches the first line on the temperature gauge.
other than that its stays the same

yes thats ok but mine goes down another 500 revs if i park at some lights etc for a few mins???

Have you got the aircon on?

no------that bit doesnt work when i press the aircon the revs drop instead of being picked up to compensate for the added load.

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..

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

jaylee wrote: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..

thats the one im on about jaylee,the solenoid on the left! the right one picks up the throttle in cold start mode and aircon on mode,but does the one on the left control the drop off further when the engine is in tickover mode with no load on it. i think it does.

wonkanoby wrote: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

thanks for your suggestion on this,mine to was all over the place when i got it,i took a long time getting the throttle cable set up as it has a few functions as you rightly said,the reason the aircon doesnt work is because it has the usuall leak at the back pipes where it goes up to the matrix it did work initially but obviously had not been used enough in the past so the seals have failed.

all the functions other than this work,the motor is sweet and spot on.its just this 500rpm drop that has got me wondering!!!! it always does it when its running but not moving under any load.i am begining to wonder if its just the fuel side sticking up on the flow side somewhere in the pump,then the spring that controls this shuts it down properly to its correct state.

Northern Bongolow wrote:

jaylee wrote: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..

thats the one im on about jaylee,the solenoid on the left! the right one picks up the throttle in cold start mode and aircon on mode,but does the one on the left control the drop off further when the engine is in tickover mode with no load on it. i think it does.

What i discovered about the one on the left before i replaced the dud solenoid on the right, is that the plug warming on cold start the solenoid activates 24-8002 http://www.lushprojects.com/bongopartsmk2/1R29921.gif hoiking the revs to 750 as if warm acting like a choke i suppose? then drops off long before i would call a decent running temperature?? (That whole auto box lock up thing?)
The one on the right irrespective of AC seemed to hold the revs up from cold for a bit longer...

So it could be the first one on the left has something to do with the engine management cycle while up to temp? While the one on the right helps to cope with the load when the AC's on..?


Am i right in reading that one of your solenoids is shot, & that the duff unit is on the right hand side..??



If so, i could be wrong about my theory about the solenoid on the left...

So it could be the first one on the left has something to do with the engine management cycle while up to temp? While the one on the right helps to cope with the load when the AC's on..?


Am i right in reading that one of your solenoids is shot, & that the duff unit is on the right hand side..??



If so, i could be wrong about my theory about the solenoid on the left...

thanks for this jamie,i think we are both in the right area here,my findings are the same.
the right one does the cold start throttle preset and the aircon if on,then drops out when warm,or aircon off,the left one also has an effect on the pump/engine revs.but unlike your theory that its just for gearbox lock up,(it may be)mines a manual g/box,i think it may down rev the pump and fuel supply when the motor is running but not under load for a period of time,mine seems to down rev by about 300-400 revs when sat at the lights for a minute or two.as i said the motor is running brill and is really sharp,so dont think its anything sticking etc,
any thoughts.

The whole left solenoid (call it auto gear box lock up theory) Is just an (uneducated) guess on my part. I just threw it out there to see if the raiders of the ECU come along & say, No this is what happens with the left solenoid, & learn something from this myself... Cuz to be quite honest, i cant work out why there are two of em..?!!!

The two solenoids seem to work together on the cold start, i've seen that bit happen..
The right one works the idle when AC is on plus the rad fans come on too. (I think it may drop out when the turbo spools up?)

From your last post this drop in tick-over by about "300-400 revs" I appreciate you've a manual gearbox.. Would that not make the engine little lumpy to the point of almost stalling??

aaaahhhhhh your last coment my have accidently sovled the riddle
if this was an auto box the revs would need to be held up to stop the engine staling out,but as this is a manual box,this feature is not needed ,so the ecu drops the revs, maybe.

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

Yer cold start revs seem a little high..? You may need to adjust the screw on 24-173A http://www.lushprojects.com/bongopartsmk2/1R29921.gif Or that equivalent..

Mine is set to compensate for normal tick over... I think?

do you think they are high!.if so what would lowering them achieve,just bashing things around you understand!