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kevinatkins

Hi folks,

I was driving my P4 a couple of days ago and the engine just died, now fails to start.

Found fuel pump not running, but have checked everything (relays, etc) - all OK. But have found that ECU isn't turning fuel pump on. So I hash wired the pump to get it running, car still won't start. Beginning to look like ECU, but my question is - if there is, say, an ignition problem, or some other problem, will the ECU turn off the fuel pump (perhaps for safety)?

I've checked internal 5V supply rails on ECU - all OK at 4.97V. I don't have further diagnostic equipment to hand - but the ECU microprocessor became slightly warm to touch, which would indicate it is at least running!

Drawing a blank - any help would be appreciated!

Thanks,

Kevin.
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Rusty 33S 16V P4

Scott Sander · Posted: Mon Jun 26, 2006 1:45 pm Post subject:

So do you know if you have spark?

Remove a plug lead and place the connector close to the engine while someone turns the engine over, you should see it spark. Of course make sure there is no flammable material around.
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Scott Sander
'91 Alfa 33 Boxer 16V Monza - Awesome
http://www.sanderfamily.com

kevinatkins · Posted: Mon Jun 26, 2006 3:48 pm Post subject:

Hi Scott,

Thanks for your reply. There's no spark, and no evidence of switching across the coil when the engine is cranked. This is looking more and more like an ECU problem. Oh dear.
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Rusty 33S 16V P4

ZeNiTh-PbArM · Posted: Mon Jun 26, 2006 7:34 pm Post subject:

hi,

to my mind this looks like TDC sensor problem (a lot cheaper than ECU)
check continuity with ohm-meter, around 3 kilo-ohms
check AC~ voltage while cranking, you should get more than 1V
otherwise replace sensor.

regards,
zp

stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

if you need an ecu ive got one for 20 quid
cheers steve
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brum brum

kevinatkins · Posted: Mon Jun 26, 2006 10:50 pm Post subject:

zp,

thanks for the tip - i'll check that tomorrow. just to clarify - the tdc sensor is located on the flywheel housing on left side (viewed from rear of car) and connects with a two-pin connector on a flying lead, yes?

stedee,

thanks - you might be a life-saver if sensor proves to be working ok. i'll post back.

thanks for your help folks,

kevin.
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Rusty 33S 16V P4

ZeNiTh-PbArM · Posted: Tue Jun 27, 2006 6:31 am Post subject:

hi,

yes TDC sensor is what you describe.
you might have a 3-pin connector (signal, ground, shield) too.

regards,
zp

kevinatkins · Posted: Tue Jun 27, 2006 10:41 am Post subject:

Hi,

zp - I measured resistance of sensor: 500 ohms approx. Voltage across sensor during cranking was about 3V AC. So I'm thinking the sensor is OK - resistance a bit down on what you specified though?

stedee - I might be interested in that ECU you've got. Please could you PM me with contact details. Thanks.

In the meantime, I will be putting the car up for sale. Hopefully as a runner if I get this problem sorted! Here's some brief details:

Body: A bit tatty; solid underneath but a bit untidy. Welded for last MoT. Rust breaking out around filler cap and along door bottoms. Paintwork fair - it's been resprayed to a reasonable standard at some point in the past.

Engine: about 105k; still strong. Following parts replaced in last six months: cambelts + tensioners; water pump; alternator; thermostat.

Gearbox: Usual synchro issues on 1st / 2nd gear; slightly noisy in indirect gears (faint whine), otherwise OK. Selector could do with new bushes - bit slack;

4WD: All working, but VC bushes worn; back axle a bit noisy - whines.

Suspension / steering: New rack, plus PAS plumbing six months ago. Everything else OK.

Interior: Fairly good - couple of small cigarette burns on driver's seat. All seat cushions in good condition. Interior isn't bad at all.

Tyres: all good - new Avons on front about 3000 miles ago; spare unused.

The car has also had a new exhaust in the recent past, new fuel tank. There's loads of history with it. I bought it to save it, did it up and got it back on the road. It has tax and MoT until January next year.

If anyone's interested, let me know and I'll send some photos. If I get her running again, I'd be looking for around £650 - I think she's worth that.

Cheers,

Kevin.
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Rusty 33S 16V P4

ZeNiTh-PbArM · Posted: Tue Jun 27, 2006 12:17 pm Post subject:

hi,

TDC sensor should be ok then.
what does flashing code for ECU reveal?
ECU failure is not common
please keep us informed

regards,
zp

kevinatkins · Posted: Tue Jun 27, 2006 12:27 pm Post subject:

hi zp,

thanks for your help - it's appreciated.

how do i check the flashing code?

kevin.
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Rusty 33S 16V P4

bobbber · Posted: Tue Jun 27, 2006 2:55 pm Post subject:

http://www.sanderfamily.com/

then goto 'Alfa Things' then 'tester T2'

Hope that helps!

Bob
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Fiat Bravo 165 Sport

sportston · Posted: Mon Jul 31, 2006 11:28 pm Post subject: use oscilloscope

The only reliable way to test a Crankshaft Position Sensor (CPS) is to check it with an oscilloscope whilst cranking the engine. You should get a sine wave output. If you do then it is working. However the wave must be strong enough. Usually, at least, upwards of 6v from peak to peak if memory serves. If in doubt call out a GOOD mobile engine tuner.

kevinatkins · Posted: Sat Jan 13, 2007 6:37 pm Post subject:

Well it's been a few months since I've looked at the old 33, but I've decided to have one last go.

Further to bobber's suggestion, I made up a diagnostic test light, and found the ECU issuing a code of 4-4-4-4, which suggests no fault found. I have also tried substituting another ECU, results are the same.

I have checked for spark - there's a good healthy spark when cranking, but the fuel pump isn't switching on. I've double-checked the relay, which is OK, but the ECU isn't switching relay on.

The injector relay is OK and supplying 12V to the injectors, but I wasn't able to make the ECU perform an injector switching test - nothing seemed to happen.

I'm really puzzled now - I think I've pretty much checked everything obvious - relays, fuses, ECU fault codes, etc. If anybody has any ideas, please let me know! As for transport, well I bought a dirt-cheap Rover Metro, which has served very well and been 100% reliable, but it's a rather different animal to the 33, to say the least!
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Rusty 33S 16V P4

Ben_nz · Posted: Sat Jan 13, 2007 10:54 pm Post subject:

So you've got a spark and power to the fuel injectors, but two different ECUs will not turn the fuel pump relay on?
Does the fuel pump normally come on when you turn the key to the first position, before you start cranking the engine?
Are you sure it's not something simple like a bad connection or broken wire between the ECU and fuel pump relay?

kevinatkins · Posted: Sat Jan 13, 2007 11:16 pm Post subject:

Hi,

Thanks for the reply. Yes, there's a spark and power to the injectors. The fuel pump used to come on for a couple of seconds when ignition turned on, to prime the system, then go off again. Now it doesn't come on at all.

Regarding bad connection, I've tried strapping the switched side of the pump relay down to ground, which results in the pump working (albeit all the time..), but the engine still won't fire.

It's a really strange problem. I'm wondering whether, although the positive feed to the injectors is being established, the injectors aren't being correctly switched by the ECU. Also wondering whether there may be something else that inhibits the fuel pump - eg, throttle switch faulty?

I'm going to have a look at all the ECU sensor connections in the engine bay and see if there's anything obviously amiss. I'm really hampered by a lack of decent test gear - all I've got is a digital multimeter - could really do with a 'scope.

I'll have another fiddle tomorrow and post back. Time for the pub now.
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Rusty 33S 16V P4

16v campervan · Posted: Sun Apr 15, 2007 10:39 pm Post subject: 16v non runner.

Hi there, did you ever solve this problem. Question

kevinatkins · Posted: Mon Apr 16, 2007 9:43 am Post subject:

Hi,

Unfortunately I never was able to get the car running again. I sold it to a chap who deals in 33's and it turned out that a pipe had broken off from the fuel tank resulting in no fuel supply! D'Oh! That said, he only discovered that upon removing the tank (he was stripping the car for spares).....

So I'm currently 33-less....
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Rusty 33S 16V P4