Bosch injection pumps

Lawrence1973 · Unread post by **Lawrence1973** » 24 Feb 2009, 20:29

Can anyone help me? I have acquired a replacement pump on ebay from a scrapped 406 TD for my 406 TD - mine has been damaged by a previous owner.
The pump I have acquired isn't an exact match in model number. My pump is 0 460 494 455 and the new pump is 0 460 494 427. Question is : will it fit and work properly? Also, my damaged pump has had all the armour removed and has no visible immobiliser module. Next question: Can I fit the new pump and disable the new module? or will the new module affect things as the old system is deactivated? Are the modules key related?anyone know exactly how they work?
I would really appreciate an experts help.
Cheers
Lawrence

Unread post by **CitroJim** » 24 Feb 2009, 21:48

I'm no expert but I'll try Lawrence.

I'm assuming you mean a 1.9TD

It should be OK if both are of the AS3 (semi electronic) variant. Best if you post pictures of both pumps and I can then eyeball them for you. You can use an earlier fully mechanical VP20 in place of the AS3 but there are issues which I can cover if necessary as I've done an AS3 to VP20 conversion on a Xantia in the past.

It'll work but fuelling may need a tweak.

The easy way to tell an AS3 is that it has a round "pot" on the top of the throttle shaft with three wires emerging from it. The VP20 fully mechanical pump may well have a microswitch in the same place. These do very different things.

With regard to the armour. If your replacement pump has it removed and the stop solenoid is visible, all you need to do to get the engine running is to take an ignition-switched supply direct to the stop solenoid.

If you know the immobiliser module on your old pump is good, you can have the armour removed from your present pump and swap the immobiliser module onto your new pump. Removing the armour though is very difficult and I'd entrust this to a pump specialist. they won't charge much.

This website shows an AS3 being dismantled to reseal it and if you look at the armour removal section you'll see the immobiliser module on top of the stop solenoid.

What went wrong with your old pump?

Lawrence1973 · Unread post by **Lawrence1973** » 24 Feb 2009, 22:24

Thanks Jim, nice to know there is someone out there!

Great info. Let me explain further. I was told that to replace a pump the Bosch number must match exactly due to variations in pressure, shaft sizes and so on.Hence the numbers I referred to. Is that true? I was hoping that because I am only 2 digits out, I might be in luck.

The old pump, still in the car at the moment is the one on the website you sent as a link (thanks) (brilliant site). So it is the one with the sensor pot on the throttle shaft. The problem with the pump started when I realised that I had a really poor throttle response under load. I only had the car a month or so from an Arthur dailey type garage. I investigated and soon discovered the horror of what has happened to the poor pump!

The armour is totally gone and the module missing and bypassed to the stop solenoid. The real problem was that the full load adjustment screw was seated in what looked like a broken hole in the side of the pump. It had been glued in there with epoxy and at an oblique angle (BODGE OR WHAT) It's a miracle the pump was diesel tight. At this angle, there was no way it was adjusting the lever internally corectly.

So, In a nutshell, I could exchange the top part of the pump which would replace the faulty part (that would mean removing the armour from the new pump) Or as I have what looks like a much better pump with all the parts fitted, armour etc.- exchange the whole pump and risk immobiliser problems or other compatibility issues.
What do you think?
Thanks

Lawrence

Lawrence1973 · Unread post by **Lawrence1973** » 24 Feb 2009, 22:27

Sorry Jim, yes 1.9TD

Unread post by **CitroJim** » 25 Feb 2009, 08:09

Hi Lawrence,

Oh dear

That is a terrible and dangerous bodge for several reasons

Still, no worries, as long as the new pump looks the same (i.e. it has the load pot on the top, has the same electrical connectors and came from a Pug or Cit 1.9TD, it'll work no problem at all. You'd be amazed how you can swap pumps around

If the new pump is still armoured, you'll only be able to use the immobiliser on it if you know the keypad code for it (assuming your 406 has a keypad) If your car has the later RFID immobiliser, you won't be able to and the pump must be de-armoured to remove it and get to the stop solenoid. As I say, de-armouring a Bosch is tricky at the best of times and whilst I've done it once I will never do so again as the risk of damage is huge, mainly from the fact that you have to remove three tapmper-proof screws from the distributor head and there exists a risk of breaking the HP pumping element. Swapping tops (once the armour is off, is possible but all seals MUST be replaced.

In short, the best course of action is to have your new one de-armoured by a pro and replace the bodged pump presently on the car. You'll have to live without an immobiliser but hey...

Incidentially, the bodged screw is the maximum fuel delivery setting adn must never be tampered with. Amongst other things, it controls the maximum off-load speed of the engine and if maljusted, the engine is in damger of overspeeding and this could prove fatal if a gearchange is missed or you have an over-zealous MOT tester on the job. The screw should be set so the engine just red-lines off-load.

The actual pump removal is not too bad a job. You'll need a 13mm half-moon spanner, lots of patience and most importantly, a small puller to pull the drive sprocket off. One can be made easily enough and somewhere on here is the instructions on how to make one. I'll see if I can find it for you.

One point to note is the pump fixing nuts must be done up very tightly and the washers must be present. If not, the pump will rattle itself off it's mount very rapidly...

Lawrence1973 · Unread post by **Lawrence1973** » 26 Feb 2009, 21:01

Cheers for all this Jim,
Well, the armour is off, the pump is separated and the top is on the old pump. All screws and adjustments are as they were.

Weird thing though, just started her up and the throttle only revs up half way then dies off a bit......when you return it to about half open, it revs up again but only to about 3,000 rpm.

any ideas? sorry about this!

Lawrence

Unread post by **CitroJim** » 26 Feb 2009, 22:51

Lawrence1973 wrote: any ideas? sorry about this!

No need to be sorry Lawrence, what we're here for

Did it rev fully previously?

Did you swap tops with the old pump in-situ on the car or did you remove it to swap tops? If not, I can see all kinds of problems that might have occurred. It's a tricky enough job on the bench to get everything back in the right place but on the car, If you managed it at all like that, I salute you sir!

Basically, if it will not rev past 3000rpm, that can only be as a result of the fuel delivery sleeve not pulling back far enough to fully open the HP pumping element filling orifice or the governor regulating the engine speed to 3000 rpm because of restricted travel.

The throttle works through a spring against the governor and does not have a direct connection to the lever that operates the delivery sleeve.

Given the origional bodge, the delivery sleeve lever may be bent as the maximum fuelling screw works directly against it. Another common error is people undo the two triangular headed screws on the sides of the pump. These are the lever pivot bearings in fact and if unscrewed, the lever moves out of position and if screwed back in again without stripping the whole pump, the lever bends and then fuelling will be very upset.

I have to say the best course of action, given the circumstance, is to put the replacemnt pump back together and swap the whole pump.

Finally, it is risky to swap tops without replacing the big seal between the body and top. It is very likely to leak and this, if nothing else, will upset the pump trasfer pressure regulation.

Lawrence1973 · Unread post by **Lawrence1973** » 27 Feb 2009, 10:14

What a wealth of knowledge!
This is so great to have this help.

Assuming that I have everything back ok, would you say that the original seal between top and bottom would be causing this sort of problem?

I really studied the whole set up inside with the governor, the small spring on the idle lever, the stop lever and how it all fits together. I did fit it all back together on the car with perseverance! I did notice that the cable to the idle lever is now slack and not tight to its slot?

I did notice that the throttle shaft seal leaked a bit after it was fitted. Would this allow air into the situation? If I have lost a good seal with the top and bottom, do you think I can get away with discarding the rubber seal and replacing it with suitable gasket sealant?

On to Glory

Lawrence1973 · Unread post by **Lawrence1973** » 08 Mar 2009, 22:00

Hey Jim, if you're still out there, SUCCESS

I changed tops back again and swapped pumps. It took a lot of work but I got there in the end. The old pump was probably contaminated from the original botch. It did work before but now I realise that this was in the broadest possible sense! there is no comparison with the new pump.

I might have to do a bit of fine tuning with the full load screw because I think it went back in a bit to far (the marks wore off)

One thing you might find helpful to know - I decided to get new timing belt and aux. belt. Whilst replacing the belts, I looked at the alternator mounting bracket and saw it was only held on by 4 bolts and with it removed, it aids taking the pump off/on considerably (you might have done this yourself)

Anyway, just wanted say thanks for all your help

Lawrence

jgra1 · Unread post by **jgra1** » 09 Mar 2009, 11:53

well done Lawrence

Unread post by **CitroJim** » 09 Mar 2009, 12:51

Excellent stuff Lawrence

Sorry I "disappeared"

I have just emerged (hopefully) from an incredibly busy time where the forum hardly got a look-in

Anyway, as both John and I say, good work!

Lawrence1973 · Unread post by **Lawrence1973** » 09 Mar 2009, 18:44

Cheers,

I don't suppose you gents know what I should be aiming for idle speed wise? I have it adjusted to about 1000rpm at the moment but it sounds a bit fast for my liking.

Lawrence

Unread post by **CitroJim** » 09 Mar 2009, 18:56

Araound about 1100 rpm cold and 900 rpm hot is ideal Lawrence.

Trouble is, the fast idle system often stops working after a while so set it at 900'ish and just accept it might be a bit lumpy/hesitant when really cold. A gentle foot on the throttle to keep it around 1100 on first start for a few moments will suffice.

If you want to get your fast idle working, we'll have a go

Do you have a waxstat, which can be identified by the fast idle cable ending in a big alloy cyliner screwed into the thermostat housing or do you have the vacuum operated one? In the case of the vacuum one the cable will end in a round saucer-like device with a vacuum pipe going off to an electrovalve and then to the vacuum pump on the RH (as you look at it) side of the cylinder head.

In the former, the waxstat dies after a few years and in the latter the electrovalve often dies...

Lawrence1973 · Unread post by **Lawrence1973** » 09 Mar 2009, 20:06

Thank you Sir,

I reckon it's not far off then. It is the vacuum type. Might have to adjust it finely as time goes on.

How do you know all this stuff?! amazing

Maybe I haven't been as successful as I thought you know. I just warmed the engine up nearly to working temp and whilst opening the throttle the engine had a sudden abrupt little hesitation but then it was ok. Oh dear......

Test drive tomorrow......

Lawrence

Unread post by **CitroJim** » 09 Mar 2009, 20:29

Lawrence1973 wrote: How do you know all this stuff?! amazing

I have a severe and incurable case of Xantiaitis

Have a read of my blogs (My main one, my diesel pump one and my V6 one) down in the members area for the full story Lawrence..

Playing with cars is a bit of therapy for me and essential to my wellbeing..

If you've not given the car a good run of late, an odd hesitation is not unusual. It'll be a bit coked up in places and a good "Italian Tuneup" will do it the world of good

On the vacuum fast-idle, the default is fast idle and the application of vacuum to the actuator on the end of the cable is what pulls the idle down when hot. Yiou can feel vacuum on your fingertip and that's a goood way of seeing if the vacuum side is working. Check for voltage across the electrovale coil when the engine is hot. Most problems come down to the electrovalve playing up. You'll likely find an identical electrovalve nearby and that one operates the EGR valve. The vacuum to the EGR valve is best disconnected to remder it inoperative but the pipe must be plugged to avoid a vaccum leak that could upset teh operation of the fast idle control and the brake servo as that gets it's supply of vacuum from the same pump.