[amitverma]

Hey guys
my '04 palio sports is in trouble. exactly a couple weeks ago, on a sunday, my car refused to start. the injector light came on. i was a bit worried that cng finally kicked the trouble train. the TDC sensor had gone kaput and was replaced the next day. everything was fine but a little while ago, the engine refused to start once again. the light came on again. it was so scary.
but somehow after a few tries the light went off and the engine started and my breathing too. i brought it home couple mins ago. now i am scared to take her out again. what do you guys suggest?
what is the problem. why is the sensor getting screwed up?

i'll have to take it to the A.S.S. but cant do that before the weekend. but i would really appreciate some help. and if anybody has any contact info abt Fiat's officials in Gurgaon, please PM me. there are a couple of qualified people up there. I had his number, but somehow lost it.

Any help would be appreciated.

[nitrous]

Is this 'Top Dead Centre' sensor the 'Crank position sensor' or the 'Throttle position sensor'?

[veyron1]

Palio has a Crank Angle Sensor, right? Does it have/require a separate TDC sensor? I'm guessing the service guys must have meant the CAS as the TDC sensor.

Check if they replaced the sensor mounted near the bellhousing/flywheel. If so, that's the CAS. If they replaced the one mounted on the head, beside/behind the timing chain, that's the cam sensor. Faulty cam sensors can cause starting problems as well, primarily because they're redundant after the vehicle has started, in most cars...

[amitverma]

i am not exactly sure as to what TDC sensor they replaced. the information provided to me was that it is the main sensor that manages all the electrical devices.
as to its position, its mounted right near the throttle and the main engine head.

on asking whether CNG is the culprit, the mechanic said it is near normal to fail around 4 years.
also, i received a call from FIAPL abt an hour ago and they said they are going to take up the matter with the dealership. Its about time Fiat put their head down in the A.S.S. deptt.

[amitverma]

ok got confirmation. the tdc sensor is the one that tells the position of the pistons to the ecm. i guess ~veyron1 had it right.
can someone point out wat might be the issues here?

[veyron1]

Originally Posted by amitverma

as to its position, its mounted right near the throttle and the main engine head.

That's the camshaft sensor, not the CAS. Sensor faults are inevitable in a car whose electricals have been fiddled with....that's ok....

In all probability, the cam sensor was fiddled whilst CNG installation for the ECM to run closed loop on startup (as is with all cars); since CNG fitment would require the engine to be started on petrol, normally, and then gradually switch over to CNG after warm-up ..

[amitverma]

but that sensor was replaced just 2 weeks ago. after the installation of CNG, that is.
it should not give trouble so soon...?

also the same issue cropped up again tonight. i switched on the car and before cranking the engine, i noticed that the central locking took some time to lock all doors. normally, the doors lock instantly on switching the electricals ON. but today it took a good 2 secs to lock. why this delay. and when i gave it a crank, nothing happened. the engine took the crank but did not come to life.
i switch off the key and try again. and this time it starts. could it be some wiring fault?
pls help me out guys...

[amitverma]

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