Peugeot 206 1.9 lx jumpy at 2000rpm

[CitroJim]

What pump did the DW8B have?

[spider]

What pump did the DW8B have?

Lucas DWLP12 as far as I know Jim.

DW8 WJZ = Mechanical advance pump DWLP11 , first DW8's this was typically used up to about 1999
DW8 WJY = Electronic advance pump DWLP12 , used from around 2000 onwards

Bosch pump (unknown ID) fitted in some rare cases, only seems to be present on very early (T plate) 306 with the DW8 as well. Never seen a 206 or anything else with the Bosch pump.

But the 'WJY' ones either have or do not have the MAF, later ones do obviously from around (estimate) 2002 / 2003

The rest of the system seems about the same for them, needle sensor on injector etc. Slightly different 'control box' on the wing for it though to deal with the 'MAF' input.

I don't have any more specific information unfortunately. Summary is early ones are WJZ with mechanical advance, then it went to WJZ (electronic advance) then it stayed with that pump but a slightly different control setup and a MAF. At least I think.



A random sidenote the high pressure pipes are different between these two, it won't run if you fit one pump type and the other pipe types...

[CitroJim]

Thanks Andy, not too dis-similar to the earlier Lucas pumps on the DW8 then...

That pump has been about for donkey's now and I think first appeared on the XUD 1.9TD in the 306..

Good pump it is too and well proven. It's only a development of the good old original Lucas CAV DPC pump.

[spider]

No problem.

Meant to add the later ones will have a "throttle" (incorrect word I know but "control lever" does not sound as nice!) potentiometer fitted usually, rather that rely on a part load switch for the EGR. No post heating as far as I'm aware. Then again post heatings tend to be turbo units.

[CitroJim]

Ahh yes, 'throttle lever' is the wrong term but everybody knows what it means and does so it's good. The more correct term would be 'governor regulator' as that's what it is ultimately what it's controlling...

The pot is the load pot and the ECU uses it to determine loading on the engine by computing how far the governor is open vs. engine speed. Governor open wide and low engine speed indicates a heavy loading... From the load computation the ECU then selects the most appropriate timing value from its set of maps and in conjunction with the timing solenoid and feedback from the needle lift sensor the pump timing is set to the computed value...

If the load pot and/or the needle lift sensor is duff then the pump timing can never be correctly set. If the Lucas is like the Bosch it will failsafe to a very retarded setting and performance will be dreadful...

[spider]

Having seen one 'without' it seemed to run fully advanced, well there was curious constant knocking anyway. it half sounded like it was about to run on its own oil (best way I can describe the sound)

[CitroJim]

Now that's bad if it defaults to fully advanced Andy

I can see how it might as the traditional 'resting' position for a mechanical pump is fully advanced to assist with initial cold starting at low cranking speeds where a significant increase in advance is beneficial. The Bosch certainly does that and then immediately retards back to normal as speed builds following a successful start...

[spider]

All I can say is it did not sound "dull" it was sort of 'crackling' really.

The same noise you get if you (for instance) on a model with mechanical advance but with the microswitch (cold running cable pulled tight) aka 1.8TD 205 , if that was switched on.

[CitroJim]

Yep, that's it. very far advanced Andy... Verging on a metallic sound...

[spider]

Yep, that's it. very far advanced Andy... Verging on a metallic sound...

Almost a valve / tappety noise but not 'constant' ie every valve as you'd hear on ancient OHV engines ( or newer engines devoid of oil! ) but regular enough a couple of times a second yes.

[CitroJim]

Yep, that's it. very far advanced Andy... Verging on a metallic sound...

Almost a valve / tappety noise but not 'constant' ie every valve as you'd hear on ancient OHV engines ( or newer engines devoid of oil! ) but regular enough a couple of times a second yes.

Yes, I'd say that was a fair description Andy...

[Dulson420]

i may of jumped the gun abit.. so ive just had abit of time to actually look what im playing with and theres no maf sensor.. i unplugged the egr (face palm monent) ive tried to clean it without pulling it off/apart anythings to look out for ie why its not working right??

[spider]

On your car if there's no MAF the EGR is a simple vacuum operated affair in most cases. The vacuum is passed to a valve (electro valve, you'll see this as a small lump with a multiplug and two vacuum hoses on it) and this valve is turned on / off via the ECU, which then means the vacuum is applied (or not) to the valve, opening and closing it.

On the DW8 the common problem is they can gum up so much they never fully close, this is bad at idle speed especially as its then trying to run on a mixture of clean air and exhaust gas. The valve normally should only open at higher 'throttle' openings and only when the engine is warm too.

What to do: If you take the air piping off around the valve if you can, just really look to see if its shut or not. I'd expect it to be a bit grubby (a bit is normal) but it should not be horrifically sludged. The sludge just stops it closing really, that's all the 'issue' is to be honest. You might actually find that someone has already disabled it via sticking something into the vacuum hose.

If you wanted a 'test' , unplug the vacuum pipe from the valve (just where its sat on top of the engine) and plug the vacuum pipe with something suitable. Please do not leave it 'open' or flapping about . Try the car like that for a journey or two (or a day) to see if its any better. You won't get any lights on as you've not disturbed any electrical components.

[chinkostu]

Unplugging the egr vac hose fixed mine funnily enough, still passed MOT!

[Dulson420]

ok will have a check / fiddle in a few minutes and get backk to you