Technical Dead 20v Marea

[Galloway]

Help :bang: I have a 1997 20v Weekend. Yesterday, my wife was driving around town when the car cut out and won't restart, it cranks over but not firing.

The injection light comes on for a few secs as normal, blinks off then back on. The fuel pump runs for a sec and goes off again. I am assuming that the ecu must be reading a fault when ignition is turned on so plugs and injectors etc can't be at fault.

There is 12 volts to the injectors and plug modules. I have resistance checked from the ecu, again injectors and plug modules are OK and rpm/tdc coil has 850R resistance. I would guess the timing sensor is the only critical one that could show up faulty on the ecu self test.

The timing belt was changed 2 years ago. The alternator belt has been shredding a bit recently but there is no sensor on the crankshaft pulley to be damaged by that (or is there?).

Can you help with this problem please.

 

[bulldog5046]

i'd be betting on the timing sensor aswell.

unfortuanly this will mean changing the cambelt again, the only good news i can give you is that you wont need to remove the cam but need to remove the pully and then one allen key bolt holds the sensor in place.

are you planning on doing it yourself or getting a garage to do it?

 

[Galloway]

Hi, I have done most maintainance on this car including the heater matrix but left the belt change to a mechanic who moved the engine sidewards but he would not do it again! The method of lifting the side of the engine up seems OK and would do myself, esp as the car is at home.

Any suggestions how to check whether the timing sensor is at fault?

 

[bulldog5046]

you can probably mesure the resistance on it however i dont have a figures to hand, if your tensioners and waterpump have been changed with the cambelt you could IMO get away with just replacing the rubber at a cost of about £16 and a weekends worth of work.

i have a spare timing sensor you can have so dont worry if you decide to do it.

if you need to change the tensioners ect you will have to move the engine over.

if your local i dont mind lending a hand, just gimme a shout

Cheers,
Ryan

 

[Galloway]

Hi Ryan,

Thanks for the offer of help but I live up in SW Scotland, (but not Scottish). I have ordered a sensor as I can't think of anything else to try.

Thanks for your help.

Regards John

 

[mountainmachine]

In the Galloway's by chance? My technical knowledge isnt up to much so wouldnt be of much help.

 

[jug]

you can probably mesure the resistance on it however i dont have a figures to hand,

jug to the rescue!


the resistance should be 774-946 ohms (at 20C)

the connector has 3 pins, one if for earth, the other two are what you use to test. on the connector if you hold the metal clip at the top the pin on the right (pin3) is the earth. so use pins 1 & 2.

 

[Galloway]

Hi Mountainmachine

Not quite, nr Lockerbie but thanks for the offer, I have plenty of time to sort it.

Hi jug

The readings you quote are for the rpm/tdc sensor which is a coil type sensor near the flywheel which reads OK. The timing sensor is an integrated circuit type device which is difficult to diagnose resistance wise. Many thanks.

Regards John

 

[Notorious131]

This probably won't help but you never no, although the fuel pump is running try checking it out.
I once had to drive over a breeze bolck on motorway at 70+mph(either that or hit an artic) the car ran like a dog and then cut out, once restarted which took some doing, the inj' light came on and had no power apparrently the ecu went in to emergency mode.
The car went to the garage and they could not resolve the problem, error codes were read and cancelled but then came back, eventually my mate at the garage was talking to someone at Fiat and they said something similar happend to a car they had and the fault turned out to be the fuel pump.
It was swapped and the car ran and still is running beautifully.
However the car was in the garage for 2 months and had cost me £1200 to get fixed.
Try checking the fuel pressure in the fuel rail as apparently early on a few Marea 20v's had this weird fault. Don't ask me how to do it tho'...

 

[jug]

Hi jug

The readings you quote are for the rpm/tdc sensor which is a coil type sensor near the flywheel which reads OK. The timing sensor is an integrated circuit type device which is difficult to diagnose resistance wise. Many thanks.

oh crap you're right! i really must learn to read. even worse the rpm sensor only has a 2 pin connector. i'm really not on the ball today haha.

the timing sensor is just a Hall sensor, so you must test it "in use". without an ocilliscope that is a tad tricky.

 

[Galloway]

Hi , I'm back

Thanks notorious131, I'll keep that in mind.

I have fitted the timing sensor and (new) timing belt but it still won't start. There was some shreds (9") of pas belt in the timing belt area but not tangled in it. Is it possible the timing has been thrown out by these getting tangled in the belt.

When the crankshaft is at tdc, the white mark on the inlet camshaft gear is 9 notches anti-clockwise from the top of the engine (measured as if the engine is vertical). Can some-one confirm whether this is this correct please. If it is suspect I will have to get a pair of camshaft locking caps to make sure it is correct.

Also when the ignition is turned on without the engine running, how long does the fuel pump run before it switches off, I have it my mind it was something like 10 secs or more and now it is only a second. There are no sparks on the plugs so not expecting a fuel pump type problem.

Getting short of ideas!

John

 

[jug]

There was some shreds (9") of pas belt in the timing belt area but not tangled in it. Is it possible the timing has been thrown out by these getting tangled in the belt.

usually it does far worse and snaps the timing belt, so it is easily possible that it allowed the belt to slip a few teeth.

why on earth did you knowingly drive the car when the belt had been "shredding a bit recently". :shakehead

Also when the ignition is turned on without the engine running, how long does the fuel pump run before it switches off, I have it my mind it was something like 10 secs or more and now it is only a second. There are no sparks on the plugs so not expecting a fuel pump type problem.

it is not set to a certain number of seconds, it runs until operating pressue is achieved in the fuel rail. how long that takes depends on what the pressure starts off at. if you bleed the pressure out you should then notice the fuel pump works for longer next time you switch ignition on.

 

[Galloway]

Hi jug

Your diagnosis is very near. The belt has slipped quite a long way on the exhaust cam but the damage is on the inlet side - 4 valves bent.

I was only aware of the belt shredding after the breakdown. It was a Unipart one and although the width and diameter are the same there is a difference in the v grooving and assume the belt has slide sideways and been forced off the pulleys, will buy fiat belts in the future.

Parts are arriving on Tues so just need to find a locking tool to make sure the cams are set up correctly afterwards.

Regards John