406 2.1 now with bosch pump

[PC2CV]

I have a 1996 406 with the 2.1 engine, it had the lucas epic pump but had a few issues with idle, random unintended acceleration, random spluttering and fuel leaks. So i have removed that setup and fitted a bosch from a 405 1.9 TD that i removed back in 2017.

The 406 is starting now on the bosch pump but is quite smokey and doesnt seem to want to rev above 2000 rpm. In what way do these pumps suffer if left sitting, and does anyone still rebuild them. I also assume some adjustment to the fueling will be needed for the 2.1 engine. The pump had the security ring on the fueling screw which i have removed and turned a full turn clockwise. Also does the pump itself need timed like an old school distrubutor?
Sorry to date the DW10 8v HDi was as old as i had changed a HP fuel pump on.

[MattBLancs]

HDi fuel pump is belt driven but not timed (just generates high pressure)

Bosch EPIC and VE pumps (and Lucas pumps) = yes, all are timed in two ways - (1) locking pin in drive pulley. (2) also slotted holes between pump body and pump bracket.
From memory Bosch and Lucas pumps (on XUD9TE) have the mounting studs on pump bracket in different positions. Not sure if EPIC Vs VE pump are same stud positions or different again, sorry.

[CitroJim]

The 406 is starting now on the bosch pump but is quite smokey and doesnt seem to want to rev above 2000 rpm. In what way do these pumps suffer if left sitting, and does anyone still rebuild them.

If you can wait until the morning when I have more time and braincells available I'll do you a chapter and verse on this unless I'm beaten to it..

Just quickly,...

Personally, I'd have kept the EPIC as they are quite fixable and capable of very good performance... All that's likely wrong with yours is duff ESOS solenoid seals and gaskets...

Swapping for a Bosch is OK but you MUST use the Bosch injectors and delivery pipes that go along with the Bosch pump. Lucas ones are not compatible.

Did you use the VP20 fully mechanical pump? The very similar looking AS3 semi-electronic cannot be used unless you use it with its matching ECU as its timing is electronically controlled via its ECU and a special injector to detect needle lift.

If you used an AS3 it might just run and give you all the symptoms you have.

Bosch pumps don't like long storage. I've rebuilt ones that have been rusty and gummy inside and rusty enough to jam the vanes of the LP (lift) pump. I recommend that before any Bosch pump that's been in storage is rebuilt before use.

I no longer rebuild pumps but can offer plenty of advice and guidance ion the subject.

I'll go into a bit more detail tomorrow if need be..,.,

[liquidhandwash]

I've done this conversion and used the Lucas injectors it ran just fine. The pump has to be timed, the flywheel has to be pinned there is a hole behind the starter motor that is very difficult to see unless you remove it. The camshaft and pump have holes in the pulleys that can be pinned with an 8mm bolt. there is a mark on the injector pump and its mounting bracket that have to be lined up. Mine ran great the pump had been sitting for years, yours may have a problem. If everything is correct and you have no filter blockage or air leaks...(you did check that first right?) the lift pump inside the injector pump has likely got sticky vanes.

[CitroJim]

I've done this conversion and used the Lucas injectors it ran just fine.

That's good to know

The way your engine is running PC2CV it suggests it's running retarded which will be the default failsafe if you are trying to use the Bosch AS3 semi-electronic pump. With no ECU it will fail to a fully retarded timing position and when retarded a diesel will run but will be very smoky, will sound 'soft' and will struggle to rev.

It's also necessary to use the Bosch drive sprocket with a Bosch pump even though the Lucas one may look similar.

The pump carrier cradle may have two sets of tapped holes for the pump flange mounting studs. One set will be for the Lucas pump and the other set for the Bosch pump. Move the studs to the alternative set of hole or again the timing may end up too retarded.

Static timing must be set as Liquid advises above. The pump should be timed by use of a Dial Test Indicator but unless you have the correct special tool or are willing to make on on a lathe it's not viable but happily you can do it by ear...

With the engine warm and idling, loosen the pump a little on its flange so that it can be rotated and rotate until there's a distinct sound of 'diesel knock'. Advance it just a little bit more until it sounds a bit 'metallic' and a bit like a petrol engine running into detonation (pinking). Then back it off a little until it then sounds about right with a bit of healthy diesel knock.

As said, if the timing is too retarded the engine will sound 'soft' and sound and a bit like a roughly running petrol engine.

Once happy, tighten the pump mounting nuts/bolts and then loosen/retighten the delivery pipe unions on the pump to relieve any stresses in them after rotating the pump.

Ensure the three flange nuts and the rear mount bolt are all done up tightly. The nuts can vibrate loose with ease and it's vital the correct nuts and washers are used.

Adjust the idle and maximum speed screws on the pump to achieve a 900rmp idle and red-line just achieved on no load with the governor wide open...

Adjust the maximum fuelling demand screw so that the engine will just red-line under moderate load. Do not overdo this and ensure the pump is set so that the engine cannot rev past its redline. The 2.1 is not a 'revver' and it will suffer damage if consistently over-revved.

Adjust the boost level screw on top of the pump 'UFO' until there's a distinct puff of smoke on hard acceleration. Again, don't over-do it.

Hope that helps a little...

Fine adjustment of the timing and fuelling can be done during road tests.

As a final job, connect the cold advance solenoid on the facing side of the pump to the glowplugs so that whilst they are active you have a bit of cold-start advance available.

Good luck!

[PC2CV]

Hi thanks for the tips

Suppose it is worth mentioning the pump is the fully mechanical variety removed from a 1994 405, absolutley no electronics other than the stop solenoid. The sprocket was also used as the lucas one will not fit the bosch pump, injectors are from the bosch.

The lucas was leaking, bosch seemed to be the more popular option especially with one sititng here. Didnt like the fact the wires going into the lucas were all starting to disintegrate.

I did move the mounting studs to the 'bosch position' all sets of holes were used to lock the engine in TDC including the flywheel one. Is there a good bosch rebuild guide still available, any threads i have went looking for have suffered from photobucket deleting the pictures.

Do you have any details of the special tool to set the timing? I do have access to a lathe and 3D printer so am happy to try to do it the correct way.

[CitroJim]

You've done all the right stuff there Excellent...

This is a quick and rough guide I knocked up a many years ago... It may be of some help....

https://eastment.net/boschpump1.htm

I'll dig out my more deeply buried information on the timing tool. In fact I may even have one buried in thee bottom of my stash of special tools...

Basically, when the engine is in its pinned timing position (TDC on cylinders 1 and 4 as far as I recall) the pump has just started its injection delivery and this is measured by how far along in its travel the HP pump piston is. This is measured by removing the hex plug in the middle of the distributor head, inserting the tool and using a DTI on the end of it to measure that distance from around 45 degrees before the timing point is reached to the timing point.

Leave it with me and I'll see what I can dig out. It's been a few years now...

To be honest, I've only used that method once and then I've relied on my ears to set the timing...

[CitroJim]

Just one more little thing... I've had this happen to me once and it was incredibly baffling and perplexing...

I once replaced a pump but left the sprocket in-situ so that I did not have to disturb the cambelt... The reason the pump sprocket has two index holes...

Upon inserting the pump drive taper into the sprocket the woodruff key made a successful and unnoticed bid for freedom... This caused the timing to be all over the place...

Worth a check before stripping the pump...

Apologies for any egg-sucking in my earlier posts but wanted to get as much information in - not knowing your level of expertise in these matters.

[CitroJim]

This video explains how to use the DTI for timing better than I can describe... It's Aussie and for a 6 pot engine but no matter, it's exactly the same for a 4 pot XUD...



I cannot find any definitive timing figure for an XUD11 with a Bosch VP20 but going between the figures I've found for a VP20 on an XUD9TE and different model of Bosch on an XUD11, around 0.65 to 0.7mm will be a good place to start...

Be careful about turning the engine in reverse to find the zero point. Personally I'd not as there is some small risk of upsetting cambelt tensioning on an XUD11 in doing this... Admittedly small but... At your own risk. Instead, turn the engine a full rotation of the pump sprocket clockwise (i.e. normal direction of rotation) and note where the zero occurs as you come up to TDC... It'll be about 35 to 40 degrees BTDC, roughly.

I searched for my DTI adaptor and found it... Turns out it's for a Lucas DPC...

I think, from the video, you can see how to fabricate one. Given the 4 cylinder engines have a bit more space it can be a straight plunger running in a simple threaded collar. Easy to knock up on a lathe... The one in the video is a super deluxe item to clear the densely packed delivery pipes of a 6 pot engine.

[liquidhandwash]

Back to your fault engine runs but won't rev, I have fixed that fault (sticky vanes) by flushing the pump with solvent. If the diesel in the pump has gone bad it makes a sticky varnish that can be difficult to remove. To flush the pump I used a fuel pump from a fuel inject petrol engine, a bucket some hoses and fittings. Hook up the hose to the pump and to the IP and remove the return line banjo fitting and remove the restrictor that is fitted to the bolt. You will need another banjo bolt or hose fitting to return the solvent to the bucket. Run the pump for 1/2 hour or so and flush out the pump. The best solvent I've used is biodiesel, if you don't have access to that you might have to try some injector cleaner, I know some have used ATF mixed with petrol.

[PC2CV]

Thanks for the info on the DTI gague
Would something like this do? Im going to guess VW were using bosch pumps also at a time.
https://www.ebay.co.uk/p/10014081774#ProductDetails

I got the car running the other day moved the pump back and fourth to listen to it running by ear as some more agriculturally minded would do, no noticeable difference.

I think ill take the timing belt covers off again to double check all is still in time correctly. Seems most likely the pump and injectors will need inspected properly having sat for so long. The 405 smoked with the same pump and that was 7 years ago.

Your guide on the pump disassembly is fantastic, i remember years ago saving your HP20 gearbox rebuild guide when i had a Xantia V6 although unfortunatley it had more issues with rust than the gearbox.

I have actually got one of those semi ECU controlled bosch pumps from a 1998 xantia in the shed, seems a good one to practice disassembling. If one of those pumps are stripped is there a way to convert them to be fully mechanical in the way the older pumps were?

[CitroJim]

Back to your fault engine runs but won't rev, I have fixed that fault (sticky vanes) by flushing the pump with solvent.

That's a crackingly good plan and a great guide on how to Definitely worth a go and a lot easier than stripping the pump. In 7 years a lot of horrid stuff can build up in a pump... Fingers crossed that does the trick!

Thanks for the info on the DTI gague
Would something like this do? Im going to guess VW were using bosch pumps also at a time.
https://www.ebay.co.uk/p/10014081774#ProductDetails

That'll be just the job

I got the car running the other day moved the pump back and fourth to listen to it running by ear as some more agriculturally minded would do, no noticeable difference.

That suggests the timing is a long way off. A relatively small movement of the pump should make a significant difference...

I think ill take the timing belt covers off again to double check all is still in time correctly. Seems most likely the pump and injectors will need inspected properly having sat for so long. The 405 smoked with the same pump and that was 7 years ago.

Definitely worth double-checking the cam-pump-crank timing again as I've known a 1.9TD run much like yours because the cam was a tooth or two out...

As said above, 7 years gives all the nasties plenty of opportunity do do their worst!

Your guide on the pump disassembly is fantastic, i remember years ago saving your HP20 gearbox rebuild guide when i had a Xantia V6 although unfortunatley it had more issues with rust than the gearbox.

Thanks! Shame your V6 died, they are still absolutely sensational to drive, especially with the gearbox in sport mode

I have actually got one of those semi ECU controlled bosch pumps from a 1998 xantia in the shed, seems a good one to practice disassembling. If one of those pumps are stripped is there a way to convert them to be fully mechanical in the way the older pumps were?

Yes, absolutely perfect as a disassembly and reassembly practice piece and a valuable source of spares as so much is the same. Sadly, due to how the timing ring is operated there's no way (as far as I know) to convert them to fully mechanical...

Between us all we'll get you sorted and have your engine running beautifully...

[liquidhandwash]

My 2.1 epic pump the timing sensor failed, and no parts were available to fix it.

[PC2CV]

I double checked the timing, yup it was off
When the cam and fuel pump were locked the crank was not quite lining up. Removed the belt, locked the crank and put it on.

Its running better, still smokey but id say now it can be timed back/forwards

The pump however is leaking, i can hear it making noises when i pump the primer bulb and diesel visibly leaks from it, possibly the throttle shaft or the head where the 4 allen keys go.

Where is the best place to get a set of seals for these pumps? Are the fully mechanical ones any handier worked at than the semi ecu controlled bosch?

[CitroJim]

Pleased to hear some progress

Are the fully mechanical ones any handier worked at than the semi ecu controlled bosch?

No, exactly the same... If you can successfully work on an semi then almost all will apply...

As for gasket sets, a quick search of eBay brings up this... https://www.ebay.co.uk/itm/182610823529