2.1 keeps cutting out

[catharyne]

Hi, Newbe here,
I have had a look through the posted questions but can't find this fault. Appologies if it has been asked before.
Can you help?
My 2.1 watercooled injection starts great and ticks over lovely (even the noisey tappets has now gone!) but the moment I increase the revs it cuts out and dies. On turning the key it will fire but dies immediately. If i leave it for a short while (2 or 3 mins) it fires up and ticks over again fine.
I can hear the fuel pump working so am asuming that's hunky dory.
Any help would be good as this happened on the way back from flying thruogh it's MOT. Now This! Arghh...
Thanks in advance!

[Aidan]

AFM signal ? check it's plugged in, maybe unplug and reconnect, without this it won't rev
is it DJ or MV engine code ?

[catharyne]

Have already unplugged and reconnected the AFM, but this made no difference. Is there a test I should do?

It is DJ engine.

Thanks for the reply.

HAve just completed the AFM checks/ tests from the manual and that all seems OK.

[Aidan]

vacuum advance on disi, vac on fuel pressure regulator, idle switch on throttle body, idle control unit would be next check after disi cap leads and plug connections and resistance values I guess

[catharyne]

Thanks for the great help Aidan. After a fruitful afternoon I have checked everything on your previous post and I have even changed the fuel filter, as I was passing. No change though. It is starting and running like a dream and I can even increase the revs slightly. However, I get to a certain RPM (No rev counter so I don't know what!!) and it cuts out. No coughing and no spluttering. It just dies. If I try to restart it immediatly iy fires up but dies again. It still has to have that 5 minute break!!! Then we are back to the ticking over and accrpting a small amount of revs.

Very frustrated! Anything else I can try?

[Aidan]

ignition amplifier unit then i reckon, the thing plugged into the disi hall sender unit, only test is swap out for another, they're in golfs and polos of the age too so plenty in scrappies

[Mr Bean]

Keep going - I had all of that and after spending several hundreds on new anciliaries including a distributor I borrowed an ECU which fixed the problem at a stroke. It would run for anything from 4 to 58 miles before stopping with the restart time proportional to standing time just as though something was getting hot. Although packing various bit with packs of frozen food made no difference. The thing which caused most heartache was that it fired up every time but died imediatelly. During the fault condition it had spark and pulses to the injectors. It had all the lights were on but no one was at home syndrome.
Hope it is something simple for you
Cheers
Wolfie

[toomanytoys]

Try another rotor arm.... cheap and worth a try... I have experienced very similar problem that was a pain to diagnose...

[syncrosimon]

Also try the Throttle position switch (TPS). The computer has a preset mode for idling, which is completely separate from the running mode. If the computer does not recognise that the throttle has been opened then the engine will die pretty much as soon as you crack the throttle and road driving will be impossible.

There is a little box underneath where the throttle cable attaches, with a wire coming out that goes to a two pin plug. With plug un-plugged insert a multimeter into the two pins on the throttle side, and see what happens when you crack the throttle. Cant remember off hand if it makes and breaks or breaks and makes, but you should see and here a little click at the same time.

This item can be adjusted, and as the spindle wears in the throttle body (gradually causing and increase in idle speed over the years) it also changes where the click is which dramatically effects the running of this engine.

If the TPS is faulty it wont run on the road.

Simon

[Grun]

syncrosimon said......

Cant remember off hand if it makes and breaks or breaks and makes, but you should see and here a little click at the same time.

This item can be adjusted, and as the spindle wears in the throttle body (gradually causing and increase in idle speed over the years) it also changes where the click is which dramatically effects the running of this engine.

Throttle valve switch should be closed circuit at idle (and at full throttle) 1.5 ohms (or less) resistance.
At all other (intermediate) positions should be open circuit (infinite resistance).

Should just open with 0.05 to 0.10 mm feeler placed between throttle valve lever and idle stop.
DO NOT ADJUST IDLE STOP............ adjust the switch position if necessary.

Mike

[catharyne]

Just fitted new fuel pump and hey, it works fine - for half a mile.
Now all the old symptoms are back.

It ran lovely after fitting pump, if only for a brief while.
Will try your other suggestions, thanks

[syncrosimon]

The other thing that springs to mind is the fuel pressure regulator. This keeps the fuel at the injectors at around 30psi for them to work correctly. If the regulator is shot then the engine wont like running on throttle, but may just struggle through on tick over and slow speeds. No easy way to check other than fuel pressure gauge, or swapping for known good one.

Just go over the engine again and check all the wiring connectors. The engine computer relies on changes in resistances in the sensors which travel down the wires to the brain which interprets them into an amount of fuel for the injectors to squirt in. Very simple, but any corrosion in any wire between any sensor and the brain can cause very poor running. Best thing to check is all connectors, and engine earth points, as the resistance can change if your engine is not earthing very well.

The injection systems need a methodical and systematic approach to identify what the problem is, diagnosing like this is a bit pot luck.

Bently and Haynes have all the test procedures.

Simon.

[HarryMann]

Yes, do the TPS (Throttle Position Sensor) next as Simon described earlier..

Also right about a systematic approach, which can be difficult in these situations (with ideas coming in thick and fast), but try..

e.g.

TPS

Earths (lots & lots of them)

Take a better look at the AFM, the potentiometer track condition itself (inside de box), and actually clean (very lightly abrade (Scotchbrite)) all the connection pins

Amplifier, hall sender, ECU

Try to determine other accompanying symptons.. e.g. excess fuel smell, exhaust grey/black smoke? How does it stop (initial hunting (revs rise and fall, but not rhythmically, before spluttering to a stop)?

There's a lot of info in Wiki here too... Petrol engines 2.1 intermittent syndrome


.. and just ensure that even though it's a DJ, it doesn't have an MV style injection setup (i.e. definitely hasn't got an exhaust (O2) lambda sensor)

[R0B]

if you filled in your profile.so we know where you are.i for one would let you try my spare ecu.if you live not too far away.

[catharyne]

Thanks again, All erm not too sure where the 'my profile bit is but will find and fill in. Sorry about that. I'm based in north Wales but if you have an ECU that I could possibly try I will gladly pay registered post both ways to try.

I am an editor of two international magazines and I have my own forum with over 9,000 memeber but I have to say you guys are the most helpful and genuine I have come across. Many, many thanks for all suggestions so far.