Toyota Aygo 2009 not starting

[Mjolinor]

My sister has just given me her Aygo. She has had it for years and it is just about perfect for my son for a first car.

It has a problem in that occasionally it will not start. If it does not start then leaving it seems to be the only thing that fixes it. After a few hours, at most a day or so it will start no problems. Crank sensor was replaced and that did seem to make it better for a couple of years but it is back to the old tricks.

It will only happen maybe once every couple of months and if it were for me I would probably live with it but my son lives 100 miles away and knows nowt about cars.

Because it is so infrequent it is hard to diagnose, it may just start working. Today I got in it for the first time in 6 months and it would not start. I got out, opened the bonnet then got back in and it started fine. It runs great with no misfires and burps of any sort.

There are no fault codes (Delphi) and the real time data all looks good.

My best guess would be an immo problem but google is not leading me to any problems they have in that area.

So anything I should look at?
Is it worth me getting Techstream, will it give me more info than Delphi?

It is the most basic of cars. No central locking, no remote locking. It even has wind down windows.

[MrDerv]

In the video below, there were fault codes logged in Immob and Engine ecu. I'm guessing you've just checked Engine ecu?

Fast forward to 25mins, it shows the cause of immob issue.

[clusters]

Maybe helps....

A problem has been discovered with the ignition switch and wiring harness on the Aygo 1.4 D-4D (2005-2012).

Monitor output voltages from the switch, scope is best to capture glitches.

[Mjolinor]

Good video that. Watched the whole thing.

Not my problem but gave me lots of information to have a go at next time it does not start.

I did not just read the engine ECU, I read everything and the only fault code was a reluctor ring issue on the brakes, no way is that going to cause the problem. All other readable items were code free.

[gmb45]

fiitc........

[Meat-Head]

Check t’ plug on t’ fuel pump.

Had odd car where it burns.

can you leave back seat out to hear fuel pump

[Mjolinor]

Failed to start today and crank position sensor fault logged so looks like I need one of those.

Any caveats about cheap ones? I am tempted just to buy the cheapest on ebay as I do not know if owt else is wrong with the car that will make me scrap it until I have used it a bit.

[Jasko93]

What DTC code? I've never seen a sensor go bad. Check the electric harness going to the engine controller if it touches the body somewhere under the front glass.

[Meat-Head]

Aim for a quality brand not an ‘Itchy Fanny’ one.

Delphi, Beru, Camibair (cheese name) I had a vehicle that was a right pig to start, had some rare fault codes, ran fine. Just before I got it had an new crank sensor fitted.

I nicked a another crank sensor out a scrap engine, from there onwards *INSTANT* starting every time and the weird codes all went. (Ashtray full, rocket launcher error, random codes).

[Mjolinor]

What DTC code? I've never seen a sensor go bad. Check the electric harness going to the engine controller if it touches the body somewhere under the front glass.

It is certainly bad. Oil coming through it and the metal cap rotating freely is a give away. Whether or not a replacement fixes it remains to be seen.

It is an FAE sensor and their reputation does not seem good.

[clusters]

Those sensors very susceptible to air gap. You may get a signal but low amplitude if the gap is too big, or crap signal if the cap is hitting the tone wheel.

[Mjolinor]

New sensor fitted, no start.

Time to follow flusters advice and see how close it is. That does not seem easy.

Maybe time to follow meatypervs advice and check the fuel pump. Being a manky old git I could not hear it even if it is working, deaf as a post.

[Mjolinor]

Fuel pump works fine on cranking. Sprayed the inside of the car with petrol, it needed a clean anyway.

[Meat-Head]

Missed opportunity for a match.

could have put a scope on it and looked at the lumps

[Meat-Head]

When no start what are you loosing?

unplug crank sensor, put voltage meter on fuel pump, crank, just for a reference