Hello! Sorry for my bad english.

I have recently bought a Felicia Pickup that is powered with 1.3MPI 40kw engine. 

I have done some work to get it back on street, but it still needs more work to be done. 

 

The main reason why i am posting on this forum is that my felly ran into error that i have not figured out. 

 

When i think of the past the first time the error occured was when i bought the car. Previous owner started the car for me so i could test drive it (it started pretty good). I did not feel any bad behavior from the engine. After we made a deal and i bought the car, i tried to start the engine to take felly home but the engine just did not start. The starter motor ran just fine but engine did not fire up and i could smell gasoline from the exhaust so i assumed that it could be a spark problem. Somehow i managed to get the car started (did not do any repairs, just waited a while and tried again). On my way home i felt that the car is a bit misfiring but that disappeared when the engine got warm. When i got home i tried to start the car multiple times and it started nicely every time (engine warm). The next day i removed the spark plugs to see if they were worn out. They were in really bad shape so i replaced them with NGK ones. The car started fine and had no rough idle, no misfiring and i could not feel any loss of power. The engine ran perfect to me. 

 

I jacked up the car to replace axles, steering joints, wheel bearings, brake discs etc. The car stood on jacks about a week. So i got it back on its wheels and i decided to go to a test drive but it refused to start again (same symptoms as before). So i found out that there was no spark. Did some searching on forums and found out that the ignition coil is common to fail on 1.3mpi. Measured voltage and ground wires to coil and they seemed fine. Also i did not notice any corroded connectors. So i bought a new coil but it did not fix the problem. 

 

Next day i tried to start it and it started first try. No rough idle, no misfire. Tried to start it at different situations to see what triggers the error, (cold, warm, multiple times in a row etc) but it started very good every time. 

 

Few days later the car refused to start again (stood few days in garage and i did not use it after the previous "different situations startings" i mentioned before) 

 

Bought a new crank speed sensor because i have been struggling with bad crank speed sensor before on few Volkswagen cars. (caused intermittent starting failure). Suddenly it did not help too. Took a VCDS to check for fault codes. On engine there was only one fault code: 

 

17978 - Engine Start blocked by immobilizer 

P1570 - 35-00 - 

 

Tried to connect to immobilaizer unit but could not get connection.

Searched forums and got a nice wiring diagram from here and some tips and advice what to check. The wires are all good. Grounds cleaned and tightened. Battery voltage to immo unit is applied when IG is on. Ignition ring resistance was pretty close compared to forums one (0.1ohm difference). 

 

Found out that the car had aftermarket immo system with door locks and alarm system. Removed all that. Got it started. Next day the problem still occured. So no success. 

 

Took the ECU to a friend of mine who coded immo off. Installed it back to the felly. Did not start at first try but at few attempts it started. I took off immo unit connectors to test if immo was off and it started so i assume that immo off is working. But the day after that it did not start again...

No fault codes. 

 

Took apart the relay box, checked for moisture, tested relays, checked fuses everything seems fine. Did some more random maintenance and measurements i planned to do anyway (injectors clearing and o-rings replacement, throttle body cleaning from carbon, measured compressions [11bar, 11bar, 10bar, 10bar The results from 1st to 4th cyl], changed battery.

 

I have tried battery off over night but no success. The felly just seems to start whenever it wants. 

 

Yesterday i discovered something weird. Took out 1 spark plug to check for spark and looks like it sparks just once even though i rotate the engine for much longer than just 1 firing cycle. 

 

Posting some links here for the spark video and pictures of ECU, relaybox, vcds values etc.

Link for pictures https://flic.kr/s/aHBqjzF2V5

Link for the spark video (sorry for bad quality and darkness but you will get the idea of what i mean) 

 

So where should i look next? Any advice?

Thank you!

I don't think that the immobilizer was the culprit - if it blocks the engine, it starts, but cuts out after about 1 sec.

What year is your car? Early ECUs had some issues with the warm starts, where it needed a bit of throttle to start. Also, bad temperature sensor readings can lead to this behaviour, as well as a bad contact.

About spark plug video - the ignition module needs both spark plugs connected to an ignition coil to work properly, as it is a wasted spark ignition system.

Edited 9 March, 20224 yr by Papez

Thank you for your reply Papez. About the immobilizer thing (the engine should cut out after few seconds after it starts), at first i thought the same thing, but because of that error code (engine start blocked by immobilizer) made me think that it could be a problem and i was not sure how felicia's immobilizer behaves to block engine from running. At first i was looking for a second immobilaizer unit (because i could not get connection to it via vcds, but the wiring seemed ok) but i could not find it nearby, so i thought that coding immo off was easier.

 

The car manufacture date is 2001 but i am not sure about the ECU if it has been replaced before and i have also tried to start it with a little bit of throttle.

 

About the temp sensor. Vcds readings about that sensor were good. At cold start it stood nearby the weather temperature, and when the engine got warm it got up to 85-90°C, but the connector has been broken and previous owner has cut off the connector and straight connected the wires to the sensor using universal wire connectors.

 

You are right about that ignition module. I forgot that it is using wasted spark system and i will test it again soon with all sparks attached. Forgot to mention before that when i changed the crank speed sensor i also checked the flywheel teeth for any damages or wornouts but i did not recognise any.

4 hours ago, HardoPiiri said:

i am not sure about the ECU if it has been replaced

Doesn't the scan tool give you dates and parts (and serial?) number for ECU that could be cross referenced with the age or build date of your car?

 

4 hours ago, HardoPiiri said:

i am not sure about the ECU if it has been replaced

Doesn't the scan tool give you dates and parts (and serial?) number for ECU that could be cross referenced with the age or build date of your car?

 

Something like below.

 

 

On 08/03/2022 at 16:28, HardoPiiri said:

i replaced them with NGK ones.

 

Which NGK? I had some problems with them in the past.

The pins on the relay box look very bad to me, did you spary them with contact cleaner?

On 08/03/2022 at 14:28, HardoPiiri said:

Took a VCDS to check for fault codes.

On 08/03/2022 at 14:28, HardoPiiri said:

Tried to connect to immobilaizer unit but could not get connection.

What level of scan tool did you use, make model App?

 

Any live data?

 

On 08/03/2022 at 14:28, HardoPiiri said:

I have tried battery off over night but no success.

Was that as a reset, if so after disconnecting the battery did you turn the ignition on a press the footbrake to empty out all stored electric?

 

Saw you done relays and fuses, have you checked wiring from battery posts forward, through ignition switch, alternator, starter, earths, comms, bell and wiggle tests?

 

Checked - temp sensor DIY wiring connections, MAF and connections,  lambda and connections - physical and readings?  (in case it is a combination(s) of issues presenting as one problem)

 

An intermittent problem like this makes me think of poor connections, communications or computer program glitch.

 

That is me out of ideas.

 

 

 

@HardoPiiri

Nothing wrong with the immobilizer. The error might have been there for a long time. Usually you clear the error and see if it shows back up after 2 engine starts.

It is indeed a spark problem. Usually it is a corrosion problem. The connectors or the wires themselves. Have a very close look at the wiring between ECU and electronic ignition, connector included. Spray liberally WD40 in the connectors.

@HardoPiiri No problem with your english, this is not a club of Oxford graduates. Put Contact cleaner in connectors.

Thank you all for your support!

I think i got it figured out. I took an extra pair of hands to test the sparks and there was no spark. So i decided to wiggle connectors at engine bay but no joy. Swapped back the original crank sensor and got sparks! Assembled everything back together and started the car. Fired up very good. Wiggled the sensors connector while at idle and the car shut off. So i think the problem was bad connector and Non OE sensor combo. The connectors pins seem fine (no corrosion) but i can see broken isolation right next to the connector so i think i am going to change the pins so i could attach new wires to them, or just look for a new connector.

 

Thank you all again and i will post here if there is still a problem. Hope that will help someone solve their's

 

Well done.

 

15 minutes ago, HardoPiiri said:

So i think the problem was bad connector and Non OE sensor combo.

Yes both are common problems, poor quality modern made, or wrong, new parts fitted and connections.  With old cars if there's a problem in an area think of the last time a part was replaced there or work done in that area.  If an old part is work it often pays to keep it for a while in case the new part plays up.

 

19 minutes ago, HardoPiiri said:

Wiggled the sensors connector while at idle

Well done on using proper diagnostics, plugging machines in and looking at codes is only a start, physical and environment testing is conformation.

 

17 hours ago, HardoPiiri said:

Thank you all again and i will post here if there is still a problem.

The lesson that should be learned from this issue is that you never buy parts unless there is evidence based on a thorough diagnosis.