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Roger Blassberg

ABF engine died

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Had instant engine cut-out in the Passat last evening, tacho died, all warning lights came on, just as if I had turned off the key - in the fast lane of the M1 :shock: !! Had to sit there for 15 minutes before the Police turned up to stop the traffic and push me to the side. Now that is a laxative experience.

 

Car trailered home now, but what can it be? The cams are turning, so it's not the belt; engine turns but not firing. I have checked all fuses and checked all relays are good and secure. I had a general rummage aroud and found nothing obviously amiss. Full tank of petrol.

 

My first thoughts are 1) Crank position sensor - where is it on a 2 litre 16V ?? 2)Ignition switch. 3) Fuel pump relay.

 

All thoughts, and a clue as to where the CPS is, are welcomed.

 

Best wishes

 

RB

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bloody hell mate i'd have been out the car and heading for the hard shoulder ASAP! cant help with the fault unfortunatly...

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A hard fault like that should be easy to sort.

 

I would, if I were a betting man, stick a fiver each way on the dissy. No output from the hall sender = stop.

 

The Crank position sender is somewhere on the front of the motor I thnk under the alternator. There are 3 plugs above the front engine mount 2 are for knock sensors, the other looks to go to something under the alternator which I guess is a crank position sender.

 

Hook it up to VAGCOM and see what it thinks is broken is the quickest way to find out.

 

Gavin

 

EDIT can't find a CPS on a (guessing 95) ABF passat in ETKA

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i'd have been out the car and heading for the hard shoulder ASAP!

That thought occured to me too --for about 2 nanoseconds. I wouldn't have made it across three lanes, the traffic was very heavy and I decided to stay put. Fortunately the light was good, the traffic was moving relatively slowly (40 ish), and my Guardian Angel was in attendance.

 

Dom , no I haven't checked fuel or sparks yet; by the time I got home I was fed up and it was dark. Local specialist is coming over later with the 1551.

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Local specialist is coming over later with the 1551.

 

Anyone with me on the dissy? Evens

Ign switch 3/1

coil 5/1

pump relay 5/1

 

Anyone else?

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Local specialist is coming over later with the 1551.

 

Anyone with me on the dissy? Evens

Ign switch 3/1

coil 5/1

pump relay 5/1

 

Anyone else?

 

 

 

i'll go for the fuel pump :wink: ............what odds you giving me then mate?

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Local specialist is coming over later with the 1551.

 

Anyone with me on the dissy? Evens

Ign switch 3/1

coil 5/1

pump relay 5/1

 

Anyone else?

 

Yep, my first thought is the hall sender, I had this on my Golf, everything was dead, and typically the final thing I checked was the hall sender, luckily I had a spare.

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A plug out, smell petrol? No - Fuel Pump Relay.

Check for spark. No - check coil for 12 volt, yes - look at hall sender.

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I have got a spark, but no fuel smells when cranking over with the plugs out.

Fuel pump whines/buzzes but for more than 10 secs at zero engine revs. Some pressure in the fuel rail, but not much. Sounds like the fuel pump and/or filter.

 

Incidentally there is a CPS; would it spark, but at the wrong time, if the CPS is bu@@ered ?

 

All further comments/advice/bets are welcomed.

 

Best wishes

 

RB

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Did the 1551 snag the CPS?

 

Some pressure in the rail, did you undo something to prove that?

 

The pump should prime when the ign is switched on. After that it should only run with the engine turning. Could be part of the pump relay failed. If you jump the contacts in the fusebox, then try it, it might run.

 

Proving the relay to be the fault??? Or pull the cover off teh relay and look for dry joints which are pretty common...

 

Failing that, RW1 will be along soon I am sure :mrgreen:

 

Gavin

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'ello, do I have to fit the little fashing amber lamps? :lol: :lol:

 

No fuel as the original post = fuel pump relay, check it by substituting- a ordinary relay will do for a test but not for perminant fit as the FPR contains a rev limiter and crash/ stall fuel cut off circuits.

 

All fuses I assume are OK?

 

Fuel pump humming? Obviously the relay supply 12 volts OK? If so, fuel pump whacked.

 

Next - injectors

 

After that, has the Digifant ECU popped.

 

If you're still haven't bottomed it, I'll look deeper at tea time.

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Had look around.

 

THe CPS (G28) is the bottom connection of a stack of three plugs next to the main engine loom connection on the nearside of the engine block. Wire will lead you to the sensor end bit.

 

Check the plug side pins on wire to this bottom plug, there should be three pins in the plug. Pins 1 & 3 ie. outer pins, the voltage should be 9volts and above with the ignition on.

 

CPS to engine ECU connctor wiring check, ignition off.

Pin 1 CPS connection to engine ECU 68 is 1.5 ohms max.

Pin 2 CPS connection to engine ECU 67 is 1.5 ohms max.

Pin 3 CPS connection to engine ECU 33 is 1.5 ohms max.

 

Check between all CPS plug three pins with engine ECU pins have no shorts.

 

If no wiring fault and 9 volts or above is present, new CPS (G28). No wiring faults and no volts, engine Digifant ECU is kaputt.

 

----------------------------------------

 

Another item to check is a No1 Recogniton Sender (

 

Next a wire continuity test from distributor plug to engine ECU. Ignition off.

Check pin 1 goes to pin 33 on the engine ECU and resistance less than 1.5 ohms.

Check pin 2 goes to pin 44 check --- like wise ----

Check pin 3 goes to pin 45 check ---like wise ----

 

Check all three pins in plug for cross shorting while plug is of engine ECU. Should be none.

 

If no wiring fault and over 10 volts voltage was present on the distributor plug, then Hall Effect Sender is duff.

 

If no wiring fault and no 10 volts or above, Digifant engine ECU is kaputt.

 

-------------------------

 

Ignition transformer:

Ignition off.

 

On terminals 1 & 15, the two small ones in the main body, measure resistance. Should be 0.5 to 1.2 ohms.

 

On connections in the "curved body" part, measure resistance. Should be 3 to 4 kohms.

 

If neither met, replace ignition transformer.

 

--------------------------

 

Let me know Roger B. if you are still pooped. Not much else to go at.

 

Injectors, - the rush at lunch time..... Should have written check for fuel squirting in a regular sequence. Obviously take car of the ignition to avoid a fire by pulling off the ignition lead from the centre connection of the distributor cap and leaving it to arc to the engine well away from the loose fuel. A few quick squirts will confirm all is OK or not.... If not squirting but clicking electrically, then look at fuel pump, if not electrically clicking, then engine ECU kaputt or check wiring back from injector rail for damage.

 

00000000000000000000000000000000000000000000000000000

 

Are you serious Gavin??

Early Mk1 GTi's and similar engines had a distributor rotor arm with a mechanical rev limiter built in, remember?. In later engines the rotor was replaced for a standard looking type on, ever wondered why? Yet unlike the very 1977 / 1978 early GTi's, no busted engines. Reason.... the fuel pump relay takes in pulses and monitors rpm this way. The limit is quite a bit higher than the "red line", never see it stated and probably differ between FPR part numbers. From notes it's up somewhere at between 7,200 & 7,800 rpm. It cuts back in again when the revs drop slightly.

 

Also the FPR cuts the fuel pump 12 volt supply if the engine pulses stop. Which is why you hear the fuel pump run on for a 0.5 second generally and then stop. Stops the engine flooding with ignition switch on after a bad start or ignition just plain left on. Also in a crash, it stops a breached fuel line pumping the fuel tank out until the ignition is turned off.

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Oh yeah, I remember those rotor arms. First thing in the bin, not paying 4 times the cost of an ordinary one! :mrgreen: And no one else was prepared to either, I guess that's why the engines blew up then?

 

I never tried to get to a limiter on my MK2 GTI with K-jet. It wouldn't rev much past about 6000 anyway.

 

I did know about the short prime and that the relay had to see an input that the engine was turning or it killed the pump.

 

I did a vehicle electronics course at college years ago and we did all kinds of stuff like this.

 

Why did they change the prime from after ign off on MK1s to before engine start on MK2s? Is that just to improve starting in general, following line pressure drop?

 

What about a 16V, as it has an ECU what about the pump relay? Does that have a rev limiter in it or does the ECU decided when you have had enough? :)

 

I fitted VSAM on my 1800 16V Corrado and had it so the ignition timing would let you run well past 7000 and it never cut off on me even on trackdays.

 

It'll never make me rich but all this information interests me greatly. It's also good for baffling the little kids when they turn up at CGTI meetings. :mrgreen:

 

Cheers, RW1.

 

Gavin

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What about a 16V, as it has an ECU what about the pump relay? Does that have a rev limiter in it or does the ECU decided when you have had enough?

 

Don't have more recent info on post 1992 cars. In some cases like the VR6, the ECU rev limits and much earlier than the FPR would kick in so don't know if the back-up is built in to these relays with the more intelligent ECUs.

 

It's also good for baffling the little kids when they turn up at CGTI meetings

 

Careful or the little gremlims will infest your car at the next meeting!

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Thanks to all.

 

Latest info.

 

I got it started on Friday afternoon after rummaging around with ther wiring to the fuel rail - but it wouldn't then turn off!! The thought occured that the ignition switch was defective, so I changed that (a horrible job to get the steering column adaptor sleeve off so that I could withdraw the steering lock), and it ran but still wouldn't turn off when the key was turned and taken out.

 

Now it is sulking again so it must be one of RW1's alternatives which I will start on as soon as it stops raining...........

 

BTW, RW1 you refer to the engine ECU; this is the big box of tricks under the scuttle, next to the wiper mechanism I assume. If it is bu@@ered, I assume that the one from a 16V Golf GTi Mk 3 is the same. Anybody got one surplus to requirements?

 

Best wishes

 

RB

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this is the big box of tricks under the scuttle,

 

Yip, with large long connecting plug.

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It should be the same. But beware to get exactly the same part number cos some MK3s have an immobiliser in the key which you would need to replicate in your keys.

If you get me the number of your ECU I can check which kind it it.

Gavin

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Latest.

 

I took out the ECU and took off the connector. I sprayed WD40 onto the connector and re-assembled it. I then did the same with the connector for the CPS. It started, ran smoothly and switched off normally, so I gave way to temptation and drove it around the block for a while.

 

It stopped after a few miles, was able to be started again once or twice and then stopped cooperating altogether, so I called the trusty C into towing duty.

 

(Mrs B must be stronger than I thought, because she was able to turn the wheel and brake without power-assistance. All those years with a Mk 2 GTi must have built up her biceps - must mind my manners from now on....)

 

CPU part number is 037 906 024 F

 

Next step is to call in an auto electrician and shove RW1's checklist under his nose, (and get myself a proper multi-meter).

 

Keep thinking chaps, it's good for you.

 

Thanks for your continuing interest.

 

Best wishes

 

RB

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That has a feeling of a bad connection at one of the plugs you touched! Check pins for damage/dirt and wire condition/connections at the back of both plugs in the shield covers. Check what ever else you touched as well.

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Roger, that ECU is not known, there is a 024 BF though. It is a transponder one though. ETKA lists all chassis numbers from S 050 001 onwards as having transponder keys.

 

Gavin

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I have now changed the crank position sensor (£ 35 +vat from Murray McDonald in Hatfield, Herts., as opposed to £125 +vat at VAG; a very good man to know. 01707 272686, and he does mail order).

 

What a horrible job, necessitating the removal of the starter motor, the front engine support bracket and the oil filter, all so that I could access the one piddling little locating screw. At least it gave me the chance to free up the sticky starter. The old sensor was encrusted with baked-on black goo, looked a bit like one of Mrs. B's oven trays after Sunday dinner duty.

 

So I am quietly confident that I have located the problem. Famous last words....

 

No further report as yet because I crushed the oil filter taking it off and haven't had a chance to replace it. Irritatingly, it probably didn't need to come off anyway, but |I was trying unsuccesfully to avoid the removal of the front support bracket.

 

I also managed to break the terminal block off of the reversing light switch on the gearbox next to the starter, so more expense.

 

Never mind: if I didn't have this as a distraction I would only be be wasting time.

 

Best wishes

 

RB

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