Club 80-90 Forums

That play in the cap won't effect timing at all, it's the position of the trigger wheel relative to the the Hall generator that determines when spark fires. The rotor tip is wide so when the spark is delivered, a part of it will be in proximity to the appropriate plug wire pin to jump to it; there's a lot of leeway allowed.

This DJ has vacuum advance/retard on the diz, right? And centrifugal advance in there, too? I don't see anywhere in here where you've verified that the diz is plumbed right and actually working, and that you have the right vacuum signals.

Make sure that:

a.) the vac line off the forward side of the TB, the throttle signal, is connected to the advance side of the vac pod on the diz, the side away from the diz body.

b.) since these TB's are such junk, put a vac gauge on the throttle signal line with the engine idling and make sure there is no vac there at idle, and that it increases to the same as manifold vac when you tip in. There should be zero vac there at idle, but 1mmHg. is the tolerance.

c.) you have manifold vac plumbed to the retard side of the diz pod, the side closer to the diz body. Manifold vac signal can be taken off the nipple on the rearward side of the TB, or by teeing into the plenum vac signal that goes to the fuel pressure regulator, either will do.

d.) you should have set the idle timing with DIS bypassed and vac retard line removed from the diz, idle timing to 10deg.BTDC under those conditions. Then while idling, point the timing light at the pulley and replace the retard vac line; timing should retard several degrees, probably 8-10 but I can't find the spec. The other specs for the diz characteristics are here:

http://www.brick-yard.co.uk/VehicleSpec ... DJdata.htm" onclick="window.open(this.href);return false;

You should verify the other advance actions by removing the advance line and revving gradually, to watch and measure the centrifugal advance independently (in stages up to 12-16deg. @2400rpm), then hold the revs at 2000 or so and add back the vac the advance to be sure it pulls in additional advance. You can also test vac advance and retard at idle with a vac handpump attached to their respective lines, this is really the more accurate way to measure.

Finally, I always time to dynamic advance. I'll set it up to spec at idle, but then make sure I'm seeing 35-40deg. BTDC under no load at 3k rpm. I give this piority over what it is at idle, but if all is well with the diz they should already agree.


I really thought your problem had to be the throttle switch, it was classic for that symptomatically, but since you said there's no diff with it disconnected and the AFM has no flat spot off idle (also classic) then idle/off-idle timing would be the next thing I would delve into.

Matt, if you have no further use for that AFM I sent to you to try, can you please return it to me when you get a minute.

Regards

Fritz,,,,,,

PS, I will also send a pm to be on the safe side......

'tis sent. Sorry for the delay and cheers for the help.

Matt

Ta for that.


Regards
]


Fritz,,,,,,,,,,,

tencentlife wrote:This DJ has vacuum advance/retard on the diz, right? And centrifugal advance in there, too? I don't see anywhere in here where you've verified that the diz is plumbed right and actually working, and that you have the right vacuum signals.

Make sure that:

a.) the vac line off the forward side of the TB, the throttle signal, is connected to the advance side of the vac pod on the diz, the side away from the diz body.

b.) since these TB's are such junk, put a vac gauge on the throttle signal line with the engine idling and make sure there is no vac there at idle, and that it increases to the same as manifold vac when you tip in. There should be zero vac there at idle, but 1mmHg. is the tolerance.

c.) you have manifold vac plumbed to the retard side of the diz pod, the side closer to the diz body. Manifold vac signal can be taken off the nipple on the rearward side of the TB, or by teeing into the plenum vac signal that goes to the fuel pressure regulator, either will do.

d.) you should have set the idle timing with DIS bypassed and vac retard line removed from the diz, idle timing to 10deg.BTDC under those conditions. Then while idling, point the timing light at the pulley and replace the retard vac line; timing should retard several degrees, probably 8-10 but I can't find the spec. The other specs for the diz characteristics are here:

http://www.brick-yard.co.uk/VehicleSpec ... DJdata.htm" onclick="window.open(this.href);return false;

You should verify the other advance actions by removing the advance line and revving gradually, to watch and measure the centrifugal advance independently (in stages up to 12-16deg. @2400rpm), then hold the revs at 2000 or so and add back the vac the advance to be sure it pulls in additional advance. You can also test vac advance and retard at idle with a vac handpump attached to their respective lines, this is really the more accurate way to measure.

Finally, I always time to dynamic advance. I'll set it up to spec at idle, but then make sure I'm seeing 35-40deg. BTDC under no load at 3k rpm. I give this piority over what it is at idle, but if all is well with the diz they should already agree.


I really thought your problem had to be the throttle switch, it was classic for that symptomatically, but since you said there's no diff with it disconnected and the AFM has no flat spot off idle (also classic) then idle/off-idle timing would be the next thing I would delve into.

Just spent ages writing an update and my computer crashed..... In summary:

Checked plumbing aspects above.
Asked garage to check the technical bits.
Decided to go back to baseline 10deg BTDC and filled her up with Shell V-Power in preparation.
Picked it up, told running fine, wouldn't even idle when lights turned on, told it was good when warm.
They tweaked the idle up a smidge and it then kept running.
Told me the Idle Stab Valve was u/s and that the timing had been 15 deg retarded prior to them changing anything
Closing and I had to get home so I took it away.... it wasn't running well when warm, it was running like an pig on stilts
Remembered I had swapped the Idle Control Module (is that the right term, dual relay behind ORF taillight) when trying different bits and left the "new" one one since it seemed to make no difference. Swapped it back in a layby and the valve started buzzing again. Tweaked the idle back down to 1000rpm off the rev counter and it still runs rubbish. Generally the engine seems a lot louder too

Was just a problem at at one given condition, now it runs rubbish across the range!

So...

Can you time it properly if the Idle Stab Valve isn't working (or the Idle Control Module for that matter) ?
Could it be that it is now right, but there is still 95RON in there so that's why it is running rubbish? (was about 1/8 full of 95 when I filled it)
or have they just c0cked up the timing or something ???!!??

Sorry, still a bit of an essay 2nd time round.....

provided you can run the engine to get it warm you can time it and set up the idle etc.. base settings without any of the other gubbins working, idle control is the icing on the cake, sounds like someone hasn't been disconnecting stabiliser and vac pipes and blocking them etc when timing and setting up previously for that ammount of error
you'll have to use digijet section of bentley for order and procedures but ignore lambda and co values, use in conjunction with haynes values for dj values
check timing with idle bypassed
check idle speed with idle bypassed
check co requires idle stabiliser to be working, so check idle stabiliser then co
check throttle switch as part of idle stabiliser
check ignition parts
if not any of this then I reckon you are onto checking injectors and fuel regulator, obviously the fuel filter has been changed and the tank vants ok

Been in again. Apparently the Idle Control Module (dual relay) i'd fitted was also failing, but in a different way! One was giving an earth to one wire of the Stabilisation Valve and the other was giving an earth to the other wire!??!?! On the hunt for a "new" module now.

I think that the previous owner when timing it more likely just kept retarding it until it ran mostly OK.

I've just read through this whole thread and now I'm a bit terrified. I know nothing about mechanics, and have never driven a van before, so when I bought mine last week I got my dad to drive it home ( ). That was more than a 50 mile drive, and it managed it fine. So a few days ago I thought I'd be ok to take it for a little run on my own to get used to it. It started out fine for the first couple of miles, got it up to about 55mph. But when I turned off onto a little side road, that's when it started jumping about. Went into 2nd gear, and it was jumping and banging like it was going to stall, as if I wasn't giving it enough revs. Up into 3rd and it was even worse. So I pulled into a passing space (single track road there), and started again from 1st. Managed to get it to the end of this road ok, and had to get home, so went onto the main road... mistake! About a mile to the nearest parking place, and I had to pull over twice into people's driveways to let the queue clear (couldn't get above 25mph!). 1st, 2nd and 3rd gears were all awful, it was very scary! Once safely parked I'm afraid to say I had to call my dad to come and get it home for me . I left it running incase it wouldn't start again. He revved it and said it sounded like it was misfiring, and that it could be something electrical maybe, but he managed to get it home (maybe the fact that it had been idling for a while made it run better?). I don't understand why it would be running ok for the first couple of miles though?
This is why I want to get it serviced as soon as possible, I'm afraid to take it out again if it's going to do that. Now reading this I'm thinking I might be a bit naive to think a service would fix it at all... and I don't know anything about engines myself!

? 251 907 393 A early dj got one here works as far as i know but i haven't got a working dj system to check it on, mines MV I run suffix D

Mine is currently a 393C, not sure whether there is a significant difference!?!??

C is the later version that was fitted to DJs I don't know when the cross over was, my MV van feb 88 had a B version originally but when I sourced a replacement I found a D.
C is what you'd buy from classic if you were buying new now, could be just a supplier change or minor mod difference, this A was made by VDO and is 11/86 manufacture so came out of the first van I broke which started and ran ok, drove it 40 miles and broke it for spares.

Aidan wrote:C is the later version that was fitted to DJs I don't know when the cross over was, my MV van feb 88 had a B version originally but when I sourced a replacement I found a D.
C is what you'd buy from classic if you were buying new now, could be just a supplier change or minor mod difference, this A was made by VDO and is 11/86 manufacture so came out of the first van I broke which started and ran ok, drove it 40 miles and broke it for spares.

You have PM

Cheers Matt ,AFM and cheque turned up late afternoon.


Regards
]

Fritz,,,,,,,,,,,,,

In this post ..... viewtopic.php?f=2&t=47024&p=7327577&hil ... e#p7327577 it says the following.

5. Now meaure the voltage between pin 5 and pin 8. You should see 5V......If you do see 5V then your ISCU is more than likey fecked.......so try swapping in a replacement.

........HOWEVER - if you don't see 5V it means that your throttle body switch is not closing at Idle....this is what threw me. I tested the Throttle body switch with the motor not running - moving back and forth by hand, and by using the accelerator cable. However for come reason as soon as the engine was actually running, this was enough to not close the switch at Idle!!!!!! The good folks on the Samba have suggested that it was the buttefly valve inside the throttle body that was sticking....that and/or the accelerator cable was just a little too tight.

However I see 0V between pins 5 and 8 at idle and 5V on open throttle? It is switching OK between idle, open and full and I would have thought this was correct, but this post implies the opposite. Anyone able to confirm either way?

anyone?