Hi all,

For the past year I have been having trouble with starting the engine. Originally it started with it only occuring when the engine was hot. Diagnostics showed the temperature sensor to be at fault. So this was replaced and it started ok for about 5 days. Then a coil pack blew ( i know this may not be related) so all 3 were replaced.

The dodgey starting continued, so i took it to a local skoda dealer. They said that i must have been unlucky and bought a dodgey coolant temp sensor and so they replaced it again and also replaced the EGR valve. Again the car started ok for about a week and then the problem started again.

I found a split vacuume pipe from the brake servo. I replaced this and the idle improved once the engine is running, however it still really struggles to start.

If you start it normally (ie no accelerator) then it catches and then instantly dies. The ONLY way to get it started is to turn the key and floor the accelerator untill it revs up. Once its started it runs absolutely fine. Also i should mention that now it wont start even if its hot or cold, unless the accelerator is used.

So in order to try and solve this problem the following has been done:

- New engine temp sensor x3

- New coil packs (all 3)

- New EGR valve

- Replaced Split vacuum hose

- Battery tested

- No fault codes are being created

- Engine immobiliser light goes out as it shoud

Please Help!! Does anyone have any ideas?

Thanks in advance,

Alan

To your knowledge has the throttle body been cleaned at any point in the car's life?

Have you inspected the air filter and spark plugs?

Where are you located?

Hi mate, Thanks for the reply!

Yep the throttle body has been given a good clean (forgot to add that to my list of things that have been done)

Fuel filter, air filter and plugs have all been checked and/or changed and still the problem persists.

Thanks,

Alan

I'll admit knowing nothing about thes engines, but, as the chain has been known to jump a bit and alter the timing, is this what has happened and if is, why did the Skoda garage not check the static timing as its known as being a cause of difficult starting. Foot to the floor to start might be shutting off the injector spraying (common operating mode for some manufacturers to clear a flooded engine), and if the injectors are dribbling then the engine would be getting over fuelled - though the heat of a "recently run" engine would evaporate any dribbling fuel and so a hot start would be easy - but this is not so in your case - so I'd think the static timing needs to get checked and compressions checked before you buy any more spares

Hi mate, Thanks for the reply!

Yep the throttle body has been given a good clean (forgot to add that to my list of things that have been done)

Fuel filter, air filter and plugs have all been checked and/or changed and still the problem persists.

Thanks, Alan

Was a throttle body re-alignment carried out after cleaning?

Edit, maybe search this forum for 1.2 engine problems.

Edited 29 December, 201213 yr by rum4mo

I'll admit knowing nothing about thes engines, but, as the chain has been known to jump a bit and alter the timing, is this what has happened and if is, why did the Skoda garage not check the static timing as its known as being a cause of difficult starting. Foot to the floor to start might be shutting off the injector spraying (common operating mode for some manufacturers to clear a flooded engine), and if the injectors are dribbling then the engine would be getting over fuelled - though the heat of a "recently run" engine would evaporate any dribbling fuel and so a hot start would be easy - but this is not so in your case - so I'd think the static timing needs to get checked and compressions checked before you buy any more spares

Hi thanks for the reply!

I think ill have to check the timing and do a compression test, but as it runs so well once your past the initial starting of the engine i was somewhat putting them lower down the list of things to try.

Was a throttle body re-alignment carried out after cleaning?

Edit, maybe search this forum for 1.2 engine problems.

Hi thanks for your reply!

Yep have done the throttle re-learn procedure a few times, still no luck.

I will continue to search on here, but I think ive covered most of what ive found so far unfortunately.

Alan

Starting to wonder whether leaky injector(s) might be the problem here, as run4mo mentions.

If it runs fine once started, it does seem that compression and timing are probably OK; but I'd definitiely be checking both as it isn't hard to do.

Not sure of the best way to check for dribbliness of injectors, I guess just pull them out of the intake after engine has been running, and see if they drip? Fire extinguisher handy might be a wise precaution...

May be worth acquiring a spare set from a breaker or ebay if they seem suspect. Should be fairly cheap/easy to get hold of 2nd hand, though a slight gamble on what you get. I've heard someone on here refer to problems with the injectors on these, but nothing more specific unfortunately.

Hi thanks for the reply!

I can do a leak off test on the injectors and I haven't tried that yet! Could well be a possibility.

Thanks

Alan

Hi There

I have exactly the same symptoms with a Fabia 1.2.

it can sometimes not start when it is hot and has held 20-30 mins

When it gets cold starts fine. A cooling water sensor is changed and an exhaust sensor, it has not helped the problem, now is the lamp power steering also begun to illuminate even if the power steering works fine, and there is liquid enough.

The problem is very intermittent, and I have googled a lot, and found out that this model has a weakness with the wiring harness on the left side behind the battery box that irrer due to moisture.

Skoda familiar with the problem, but does not change the extended warranty or without charge.

So next week the battery box peeled away, and all wiring up to the windshield will be checked for errors and moisture.

Regards Brian

Hi There

I have exactly the same symptoms with a Fabia 1.2.

it can sometimes not start when it is hot and has held 20-30 mins

When it gets cold starts fine. A cooling water sensor is changed and an exhaust sensor, it has not helped the problem, now is the lamp power steering also begun to illuminate even if the power steering works fine, and there is liquid enough.

The problem is very intermittent, and I have googled a lot, and found out that this model has a weakness with the wiring harness on the left side behind the battery box that irrer due to moisture.

Skoda familiar with the problem, but does not change the extended warranty or without charge.

So next week the battery box peeled away, and all wiring up to the windshield will be checked for errors and moisture.

Regards Brian

Hi thanks for the reply!

Ill have a check of the wiring and see if that helps.

Alan

Hi all, thanks for all the replies.

Finally managed to SOLVE the problem. So thought id post back incase anyone has similar.

The problem as it turns out was a failing crank sensor or "engine rpm sensor" as it is also somethimes known. The sensor was not throwing the engine management light on the dash and also was not showing any fault codes. I was only able to determine it was faulty by looking at its ouput on a scope.

The new sensor was around £29. Its a bit of a pain to get to and is tucked in behind the inlet manifold.

Anyway, replaced the sensor, reset the ECU and now (fingers crossed, touch wood etc) all is runing and starting well.

Thanks all for your help.

Alan

Well done for sorting this, and well done for posting the solution for the benefit of others.

As a further benefit to us, can you describe what the sensor's oscilloscope trace looked like when faulty, versus what it should look like?