Strange brief drop off of revs from 750rpm -200rpm when at a standstill

[hotpot8200]

Hi just wondering if anybody has any idea`s or could point me in the right direction due to a slight issue developing after having some basic work done.The work done was as since I have owned the bongo it has never had gearbox ATF changed .So Booked it in to a experienced bongo garage and had the sump dropped new gasket and filter and new ATF .
Now my problem which in 3 years of owning and never experiencing this problem is same as in my title .
Basically on a drive the bongo has developed a strange fault of when at a standstill at a junction or lights and still in the drive gear but with my foot on the brake pedal momentarily it jolts best way to describe is if it is trying to go but then revs drop off from tick over 750rpm to a sharp 200rpm and feels like going to stall but as only a brief second returns back to normal revs and away I go .On the drive the next time stop or standstill it appears just to flutter and slight drop in revs and sometimes on same drive its ok.Revs wise all is ok on tick over when in park or neutral just when in drive not sure whether people live with this sort of issue and just select to neutral when a standstill as is it doing any harm as its not stalling.
Basically just looking for any advice or help or if anybody else has had this problem its a 95 2.5TD .Is this problem i have mentioned down to the gearbox maintenance work I have just had done? or just so happened at a similar time.I spoke to guy who did the work and he assures me not the gearbox but reckons it could be fuel related .Also It was at the garage waiting for the work for 2-3weeks as he was busy and I did`t need the bongo and he is saying sometimes after a standstill bongo don`t like it and to see if problem persist.
I have noticed odd times but not always and only after ATF work and again don`t know if this is related but the accelerate pedal seems to have a very slight flat spot as if for a second does respond when first pressing the pedal on a start from start but then responds and goes not sure if I am imaging that but you just seem to get to know your bongo and running noises etc and this just seems to of registered as if i have never had or noticed before .Any help advice would be much appreciated thanks

[mikeonb4c]

Whereabouts are you based hotpot (though feel like should know )? Adrian in Bury is aways worth a visit.

[teenmal]

What vehicle do you have,?

[mikeonb4c]

What vehicle do you have,?

[the1andonly]

What vehicle do you have,?

?
op
Basically just looking for any advice or help or if anybody else has had this problem its a 95 2.5TD .

[Northern Bongolow]

steady lads, we have all done it.


first thing to check would be the atf level, sounds like someone may have filled it to the level marker on the stick with the engine not running.

[teenmal]

Ha Ha, didn't notice it hiding in the long grass.

[teenmal]

As usual check the Fluid level, I would mention to the mechanic that carried out the work on your vehicle "is it not possible that the wiring to the Solenoid Pack might have been disturbed".

[hotpot8200]

Hi thanks for responses what does the solenoid pack do and is it easy to knock ?.
Again driving and testing today I think its a gearbox issue but can`t see how a good gearbox running all ok which had a straight forward sump removal, filter and fluid change would result in a problem .
To test i took on a empty car park and stopped started via applying accelerate pedal and when problem occurs which is not every time i stop but it appears if it is trying to jolt forward and go although my foot is firmly on brake pedal then the revs drop off to around 250rpm all of this is within seconds but I am noticing that after this it feels like it is in no gear for a few seconds and as i am pressing the accelerate pedal and revs increase the bongo stays still for a second or two then seems to just go as if engaging when as before it was so smooth and responsive when setting off from a stop .
Will double check the AFT but sure when I did it was correct (bongo running and checked with handbrake on both in drive and park selector position just a few bubbles).Seen a small video off the mechanic when he did work and bongo was put well up in air on electric ramps so would guess plenty of space for removing sump to full drain and work around without knocking anything.

[Northern Bongolow]

if you just remove the sump with the correct amount of oil in it you will get very wet, the oil level is normally above the sump split level so a good mechanic may have sucked most of the oil out before dropping the sump, to do this you may have to put a suction pipe in down the dip stick tube, this tube may have interfered with the solenoid /block /wires.
it maybe a good idea to go back into the sump and check, and to check the filter is ok and fitted right (O rings missing etc.)

but check the level first and the connection to the gearbox sensor on the side of the box.

[hotpot8200]

Thanks i see ..yes by inserting a tube perhaps could of but guess that would be un lucky as normal aren`t they flexible and how would anybody know doing that part of the job whether it caught or knocked a solenoid as that part will always be done blind .Is easy to see once sump dropped if you have dislodged or knocked a solenoid?.
Regarding the sensor is that the one mounted at same side of the gear selection lever but bit further back and lower .Brief look looks heavily oiled greased up .Is it easy to remove and clean,does this have to be unplugged when removing the sump away from gearbox.
Spoke today over the phone to a different bongo mechanic who know a lot and works on them a lot and told him of my work done and the problem which has occurred and he seems to agree with the mechanic that did the job that it sounds more of a fuel related issue and not gear box as he asked does it go through all the gears ok run smoothly when gears are changed which it does and only problem is when coming to a standstill and stopped.
So order a new fuel filter from autojapspares and cleaned the banjo filter but was fairly clean any way but he says it could the sensor which communicates to gearbox any thought`s on this ? will try fitting fuel filter any special things to do or is it just a straight change.Is it worth checking the injectors.
Again thanks all