Toyota Aygo 2006 Engine does not start

[Ra1994gh]

Hi,

I have a Toyota Aygo from 2006 with a 1.0 engine that was parked for over 3 weeks. Before I parked the car, it started and worked perfectly. I then decided to start it and it fired up, but it shut down the engine after some seconds. After we tried to start it again, it did not want to start at all. We tried mutliple times, and then we decided to tow it to the garage. 

The Battery is fine, and the starter motor cranks the engine and it sounds like it want to start but is missing something. All the lights inside and outside the car works, and we checked the ground wire to the engine.

We are getting fuel into the cylinders, with high pressure at the rail, and we are getting spark at all 3 sparkplugs. Eventhough we replaced the sparkplugs, and it did not work. We also checked the compression at all 3 cylinders, and it gave us 9,5 bars at all 3 cylinders.

We also connected a Bosch tester to the car and it gave zero fault codes at everything.

We also suspected the immubilizer chip in the key, but we tried to remove it and it then did not gave spark neither fuel at the cylinders.

I am at bare minimum now, I really dont know what to look for. The 3/4 basic things to look for is fuel, spark, compression and air, and everything is there. 

Please help me.

[rajivrattna]

You have the fuel (petrol) and fire (spark) in the cylinders and it does not run at all. That is very odd! Are we sure the timing of the fuel and the fire is correct? Just a guess.

[johnan]

In the old days I would say the "choke" is not working ie the enrichment device you used to operate by pulling a knob on the dashboard to give a richer mixture, just for starting.

However the enrichment needed for starting a cold engine these days is controlled by the ECU which responds to a signal from the engine temperature sensor to give a richer mixture when the engine is cold.

If the sensor is faulty it could cause non starting, but...you have checked for error codes via the OBD port and if the sensor is faulty I would expect an error code to show up on the reader, which you say is not showing any errors....

So it is a bit odd, unless the sensor is faulty and the error is not being reported?

[flash22]

Will it start on so ether ? aka easy start

it sounds like something electrical, poss a crank sensor

when the code reader was plugged in did it actually talk to the ecu ?

[Ra1994gh]

I forgot to mention that we have also checked the timing and everything is working properly and bothe camshafts Are timed correctly. 

And No obd faults. It connects to the ecu and reads the model, but nothing appers of faults. 

[Ra1994gh]

And the crankshaft position sensor is measured and it works.

And again the ecu doesnt say there is faults. 

So i dont really know what Else to check. 

Every time we try to start it, it sounds like it wants to start and it is just missing the last bit. 

[furtula]

Maybe the ECU is dead? Is it possible to run some tests with your reader?

[Ra1994gh]

Actually I thought of the same. That Maybe My ECU is dead. 

I have tried to do sone tests like measurements of some of the sensors in the engine and it is working. 

But could I test something Else, when the engine is not runinng? How can I know for sure that the Ecu is dead? 

I have an idendical car, can I swap the Ecu to try? 

[johnan]

Have you tried swapping the engine temperature sensor, as mentioned earlier?

[Ra1994gh]

As menitioned earlier, i tried to go in with the Bosch tester and I could read the temperature of the coolant reading 8 degrees celcius, which is the temperature here in Denmark where we live. Therefore I assume that it is working. 

But as I know, a temperature sensor Will not be causing an engine not to start, only an faulty idle and so on. 

[Ra1994gh]

But I am now not sure about the Ecu. Can I swap this with another car and try that? 

And how could i determine that My ECU is faulty? 

[flash22]

If you are getting spark and fuel and you are reading the ecu it's not the ecu

What did occur to me, as another member said is "choke" as you say you have fuel (i take it you can here the pump prime and have pressure at the fuel rail) and spark, your missing air

With the air intake hose removed can you see the plate in the throttle body move if the throttle is pressed (ignition on) ?

[Ra1994gh]

The throttle is driven by cable, and it is moving. I have also tried to spray easy start solution into it while cranking but nothing again. 

Every time we try to start the engine It always sound like it really want to start and some times it is very very close, but something small is missing. What Else could it be?

Since it is getring duel into the cylinders and spark at Every sparkplug, i would image Maybe that the timing of the firing is not correct Maybe? 

[johnan]

As flash22 suggested, is it possible to check the crank position sensor output? I would think a OBD reader would report a fault with it but maybe not.

That sensor would control the ignition timing, via the ECU. But again, you would think it would default to a get you home default mode if a fault was detected.

Valve timing is by chain and would be very unlikely to have changed.

[Zebra]

 Hello

i have 2006 Aygo with same problem died on me few days ago,
any solutions ?

[mode11]

@Ra1994gh - did you solve the problem in the end? 

My Aygo engine cranks fine on the starter, but doesn't fire. Was working fine until recently, and gets a full service each year. Tend to only do short journeys though. Had left it unused for a couple of weeks as I was away. I've taken out the Battery and given it a full charge, but with difference. 

ODB2 scanner showed one 'pending' fault code - for the crankshaft position sensor - which I have now replaced with a brand new one. Still won't start. No other fault codes.

There was previously a short buzz from the back of the car when the ignition turned on (assume the fuel pump). As of an hour ago it's not doing that now - perhaps the fuel in the rail is already at a high pressure?

 

[Nick22]

Had somebody found the solution I got the same problem 

[gotagetz]

My initial thought was the crank sensor.  When you say measured it, have you got the correct value that it should be. Sounds daft, but us the Battery definitely gpod?  Weeks of no activity won't do it any good.

[Jesperhansen]

Hello, i have the same problem, dies anyone Have a solution? 😳

[4dema]

 I had the same problem and i found Corrosion in one of the "wire boxes" beside the A-pillar  under the speaker on the driver side... took some pressured air and cleaned it, the car started afterwards... The wires was conneced somehow with the immobilizer, thats why it didnt start...