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        General >> Problems >> 24V firing on only 3 cylinders
        
(Message started by: Scorpio24v on Mar 1^st, 2007, 10:48am)

Title: 24V firing on only 3 cylinders
Post by Scorpio24v on Mar 1^st, 2007, 10:48am

While driving my Scorpio 24V it suddenly lost all power, first thought was that the transmission had popped out of gear. But after stopping it was clear that it was not running on all cylinders. Car was towed home and I checked for error codes. One code found: P0340, Camshaft Position Sensor Circuit Malfunction. Installed a new sensor but no difference.

The engine starts (after turning it over for a long time) but the exhaust manifold for cylinders 4,5 and 6 do not get warm. Easy to check as it was -25C at the time ;D

Removed the sparkplugs which seemed ok, some oil and rusthingyer on the outside but nothing much.
Installed new plugs and checked them against ground for sparks and they were ok. So I have ignition?

After again starting the car and then removing the sparkplugs they were all wet. So I have fuel?

The P0340 also came back, so checked the wiring for the sensor to the ecu, which was ok.

Does anybody have any ideas about what to check next?

Title: Re: 24V firing on only 3 cylinders
Post by scorpio_man on Mar 1^st, 2007, 11:15am

hi there

edis unit? coil pack? or......

maybe the chain has broken/jumped (hope not)?

hth

Title: Re: 24V firing on only 3 cylinders
Post by Scorpio24v on Mar 1^st, 2007, 11:45am

Thanks for the quick reply.

If the chain has jumped, shouldn't there be some extra noise? I changed the camchain tensioner last spring, as it was rattling quite much. After that that the rattle went away.

If the coil pack is broken is it still possible to get a spark from the plugs?

The edis unit seems to be located under the powersteering units reservoir and is covered in oil. I'll try cleaning it up and see if it helps.

/Jocke

Title: Re: 24V firing on only 3 cylinders
Post by Highlander on Mar 1^st, 2007, 11:57am

sounds like a broken chain, check for compression on 4,5,6

If the chain breaks in the right place there wouldnt be any noise

Your EDIS unit is screwed onto the inside of the inner wing behind the washer bottle, behind the headlight

Is it 95-98 Scorpio you have?

Title: Re: 24V firing on only 3 cylinders
Post by Scorpio24v on Mar 1^st, 2007, 1:19pm

The car is a -95 new model Scorpio.

Checked the compression and on the working side i got a value of about 160 on all cylinders and on the other side 100 (4), 100 (5) and 130 (6).
(I have never done this measurement before so the values may not be totally correct but I measured all cylinders the same way so the results should be comparable.)

So it definitely looks like a problem with the camchain?

How much do I have to take the engine apart to confirm that either the camchain has jumped or is broken?

Title: Re: 24V firing on only 3 cylinders
Post by Highlander on Mar 1^st, 2007, 2:26pm

Its not broken if you're getting compression.

unlikely the gaskets gone on all three cylinders..and even if it were it would still fire

Jumped chain possibly? or the camshaft sensor wiring?

Title: Re: 24V firing on only 3 cylinders
Post by Thunderchild on Mar 1^st, 2007, 5:29pm

Can you smell petrol on that side when you take the plugs out? I would think that if there's compression and a spark and the engine turns over reasonably smoothly, there should be at least some semblance of the cylinders firing. If not my bet would be a problem with the injectors on that bank or the fuel system to them.

HTH

Thunderchild

Title: Re: 24V firing on only 3 cylinders
Post by solarpanel on Mar 1^st, 2007, 6:26pm

take the cam cover off and check chain cams etc

Title: Re: 24V firing on only 3 cylinders
Post by Highlander on Mar 1^st, 2007, 10:24pm

He's got fuel on the sparkplugs when removed and a spark