2.1 DJ tune up help please

[sam16v]

Hi everyone I have recently bought a 1990 2wd sinka with a 2.1 DJ engine, has covered approximately 140k but seems to pull well! Sounds great, and I'm pleasantly surprised.
However have a few small issues, id like to iron out,
On deceleration I seem to be getting a bit of kangaroing, almost feels like your in the wrong gear at low revs.... also I've had some oil pushed out of the oil filler tube, which I'm hoping is the oil cap seal.....

When I picked it up was running badly, have given it a full service, new distributor cap, rotor, setup throttle switch, replaced a few split and tired vacuum hoses and a floppy oil breather to air inlet hose. Also fixed a few oil leaks, dipstick tube, and oil filler neck.
When setting ignition timing the guide I found online said to bypass the idle stabiliser, which mine doesn't seem to have? Or any sign of wiring to it? Did some djs come without this?
Also I've been trying to find a vacuum diagram for a dj, currently my fuel pressure regulator and vacuum advance port are tee'd together and piped to the throttle body? I have nothing connected to the other side of the distributor diaphragm?
Hoping someone is a little more clued up than myself on the digijet! Thanks

[cobblers]

It's probably running MV/ SR management rather than a DJ if it has no idle stabiliser. Whereabouts is the ECU located? Is there a lambda sensor?

[sam16v]

Cheers cobblers, im 99 percent sure it's all digijet stuff, looks fairly unmolested,
I'm wondering if the unit is mounted elsewhere and I've yet to find it as its a pick up? Was expecting it to be next to the coil....
I've just found a vacuum diagram in the itchy links and seems mine is plumbed incorrectly..... mine has fuel regulator and advance tee'd into throttle and no retard vacuum piping whatsoever? I'll have to check my plenum for the retard connection

[sam16v]

No lambda and Ecu is mounted in the left hand compartment tray

[Aidan]

by idle stabiliser do you mean shift mechanism 'dls' 251 906 083 A



if it isn't present between coil and the TCi module then its likely the plugs are just joined together - without it idle isn't optimally retarded so not quite as smooth as it could be, but does depend on what timing you have, if you are set at 5' to run supermarket unleaded then it will make less difference than if you are running 10' and using premium fuel. I had to replace mine this year, I run at 10' and it was less smooth at idle without it.

These units are not available new , there is someone looking at making a modern version but I am not sure on timescale, unfortunately they were made by a company that no longer exists in that form and used technology that is very late 70s, early 80s and pretty much nla

vacuum pipes should be, one from the throttle body to the advance side of the disi vacuum unit and the one from the plenum chamber is split to go to the retard side of the disi vacuum unit and to the fuel pressure regulator, the two vacuums work in opposing manner, the plenum chamber has high vacuum at idle and the throttle body has high vacuum at high revs, so as you accelerate the fuel pressure effectively increases as the bypass to tank is restricted and at idle more fuel is returned so pressure effectively falls, it all helps to maximise power whilst reducing emissions at idle and smoothing it and making it responsive - hence your kangarooing due to incorrect connections

Engine management manuals available online on Syncrosport website

[sam16v]

Cheers Aidan, great help.
yup that's the module I was referring too, will have another check to see if I can find it tomorrow.....
Had a quick look in the dark last night and my vacuum connections are definitely wrong, the vacuum take off on the plenum is completely open.... so definitely un metered air, and fuel reg connected to throttle body.....
I checked the timing and it is currently set to 10 degrees. And pretty sure the previous owner hasn't filled with super unleaded, so this may also be causing some running issues?
Would it be a stupid move to set at 5 and run cheaper fuel? Or stick to shells super unleaded and run at 10 degree's? Is there a major difference in power/economy etc? Thanks again

[sam16v]

Just been ti check, and indeed your correct Aiden, the unit has been removed and male and female plugs joined together.....

[Aidan]

Sam

just chatted with Neil - 'fraid I don't have a spare dls unit, I have a failed one that I'm hoping Dave cobblers will take a look at sometime, there's some signs of heat so maybe repairable.
There are some electronics gurus in Holland looking at making a replacement unit for it which will probably be digital, they have already done the AFM as an optical unit rather than rheostat type, (available on exchange from Dream and Drive) but no idea on timescale for dls unit or if its actually possible. One issue will be the connectors so may require wiring mods too depending on what 3 pin connectors they can find.

In the meantime stick up a wanted on here and elsewhere.

Once you've sorted the vacuum connections it should run lots better
I find that 10' and E5 Super gives me better fuel economy that makes it just worthwhile but ymmv, all fuel is expensive here : )

[sam16v]

Cheers again, I'll get on the hunt for a DLS
, I'll treat her to some super unleaded. Got to say I'm impressed with the DJ engine so far seems smooth, powerful and it's nice having a fuel injection system that can be fairly easily diagnosed and setup with simple tools.

[sam16v]

Well thanks again forvthe advice, I drove it to work today and I would say stumble in deceleration is 95 percent better.

Plan to change the fuel filter and run sone injector cleaner through the system, then get the CO checked at my mot station, check nobody had been messing with the mixture.
I will wait til she is nearly empty then brim the tank with some Super Unleaded. Hoping that and a Dls unit will get her purring.

[Aidan]

DJs don't like unmetered air on the intake side, but blowing exhaust less of a problem. MVs can cope with small intake leaks but are unhappy with exhaust leaks as the lambda will read it as running lean and increase fuelling with noticeable effect on fuel economy