[Corsa B 1993-2000] Non Starting

[Kenny]

So yesterday my car wouldnt start so i thought its just out of fuel (cos it was on the light) so went to the pumps and got 5l and put it in, still the same

Anyway I turned it over and over and over playing with the throttle and eventually it threw itself into life. Left it idling for about 20 mins to get some charge back into the battery and locked it up and went home.

I came to it today to try and start it again and it lit straight into life but this time with the EML on and not idling (had to help it)
anyhow i plugged it in and it came up with 4 faults;

Crank sensor
Air mass meter
TPS (or IAC cant remember)
EGR valve

anyways, i thought what a load of s**t and cleared them out, except the crank sensor wouldnt clear, anyway tried to start again and they all came back.

anyways played about for about 2 mins clearing and trying etc etc and it sprung into life with no EML on! anyway pulled it into the garage and as soon as i step foot out the car it cut out and would not start again!

changed crank sensor and its still the same

the crank sensor fault is always there, can never be cleared. ever. and after trying to start it the other 3 come back. but they clear out

does anyone thing it could be CAM sensor as ive looked at a wiring diagram and all 3 of them components (that keep being listed as a fault) wire into the cam sensor.

also when i go into the live data and turn the engine i can see it turning at about 180-220rpm

but now the confession, i was p*****g about AGGGESSSS AGO with the egr blanking it off etc and i decided to try and pin the plug out and made a mistake, it threw the EML on and listed a **** load of codes, cant remember what they were, anyway cleared them out and it started fine. and has been fine eversince.

or have i fried my ECU

- - - Updated - - -

by the way its a x10xe engine code (always forget to put that)

[Taurus]

Welcome

Whilst ECUs don't like being spiked, if yours was running OK after you sparked it then lets assume it survived the ordeal.

I think there's a few basics we need to check before moving onto sensors etc.

First thing - you say you left it idling for 20 mins to recharge the battery. Alternators don't work like that - the old dynamos would recharge a flat battery, but an alternator doesn't. It replaces the charged used to start the car and provides the energy needed to run things whilst the engine is turning. But if (for example) you jump start a car with a flat battery, then drive it 200 miles, the battery will still be flat. Low voltage at the battery can cause all sorts of issues, so the first thing I'd do is to check the battery and give it a trickle charge. Make sure your battery is holding at least 12.5 with engine off, and look for around 14v with the engine running. Remember that voltage and charge are not the same.

Secondly - when did this last get a thorough service? Dirty plugs or filters can cause problems.

Third - you say the crank sensor code is always there, well it always can be when the engine isn't turning. The ECU will always see an incorrect rpm signal when the engine isn't running. I say 'can be' because usually they don't actually throw the code, so the fact you're getting it may be significant. (I assume you are referring to P0335)

If you've replaced the crank sensor then we'll have to assume that's not the problem. You mention the cam sensor - that can cause a crank sensor fault to show due to the fact that they two are meant to work in sync. For example, I had one where someone had replaced the timing chain and got the timing slightly out. It consistently threw a crank sensor code due to the cam sensor not being in sync with the crank sensor.

Very low idle problems can also cause this - especially on the 3 pot engine. It's always worth cleaning the idle control valve and the port where it sits on the throttle body, and clean the throttle body as well.

Check those out and give us the details of service history etc.

[Kenny]

Cleaned throttle body out and TPS sensor and put a new crank sensor in (again) and it still wouldn't start, so unplugged airmass meter and it started but would not idle, got new air mass meter coming soon will let you know how it goes, thankyou

- - - Updated - - -

Oh and it got serviced about 3 weeks ago, oil filter, air filter and a set of plugs

[Taurus]

Unplugging the AFM is the usual way to test them, sounds like it is dud. Lack of idle still suggests ICV

[Kenny]

Thanks for the input I unplugged the airmass meter and it started so it must have been over fueling like f**k anyway I got an airmass meter and put it on and it still wouldn't start.


ive checked all the voltage and resistance from all plugs and sensors related and they're all ok happy I suppose but it still won't start and keeps logging the faults EGR valve, throttle position sensor (except the plug itself because it's dark and raining and couldn't be arsed taking it off) and air mass meter comes back every now and then but doesn't stay, so I used 'Coleman's' guide to try and fix the ICV but I didn't reset the ECU, I've left the earth off overnight see what it's like in the morning


im also always trying to start it on jump leads and a spare battery, I'm just wondering if the voltage readings I'm getting are deciding to disappear under load (when cranking)

[Taurus]

Low voltage on these will cause all sorts of issues. I'd get the battery and alternator checked and replace as necessary.

Disconnecting the battery won't clear old codes. That only works on the old 8v engines. You need a code reader to clear codes.

[Kenny]

Oh, I thought it reset the ECU and I can clear codes as I have access to a garage I'll try start it off another car tomorrow with jumpleads

[Kenny]

so today I wired an earth from the ECU to the battery to make sure I hadn't lost an earth and one from the battery to the body.
Still no luck.

Cleared the codes and fit a new ICV and tried to start it, still no luck, plugs are wet I'm getting a spark but it smells like it's overfueling like a c**t anyway.

carried on trying to start it EML was coming on all this time saying TPS and EGR valve (but it's blanked off so can't be stuck open)
but this time there was an immobiliser code, but it cleared out so I put this down to low voltage, so got a fresh battery.

went into live data (this is where it's throwing me up the wall)
the coolant temp sensor is reading : -39 degrees
and the inlet air temp is reading : -39 degrees

And also in live data it says;
Immobiliser signal; Received
Immobiliser status; Active (does this mean it's on or off)
so that could be why it's over fueling.

-
also when I have ign set on no2 there is no fuel pressure but plenty when cranking but that still shouldn't cause it to start.
is it time to bite the bullet and buy an ECU

[Taurus]

First of all, if the immobiliser cuts in then it disables the fuel supply, so if the plugs are wet then it's not the immobiliser.

EGR - if it's blanked and disconnected then you will get a code for it. Or is it still connected?

The readings for the CTS and inlet air temp - -39 is the default reading when the ECU isn't seeing a signal from them. So there's a significant clue, and it accounts for the overfuelling. Either both sensors are dud, or the there's a wiring break on both of them, or it's the ECU gone bad.

You can ignore the inlet air temp as when they break it doesn't really affect things very much. I'd check the CTS voltages just because I like to know what's going on. But the lack of fuel pressure at no.2 key position - put alongside the other issues - does make it more likely the ECU may be the issue here. Yours obviously survived being spiked, but by the sounds of it you've had a dying battery in there for some time and low voltages can cause problems with them.

If you get an ECU don't forget the transponder and key chips to match.

[Kenny]

The EGR is still connected and stuffed under the battery tray but has been like that for months with no problems

as as to the cts sensor voltage I'll check that today and replace as necessary but by now I'm pretty sure it's the ECU

thanks again

[Kenny]

Tried a new cts on it, still no joy, ECU ordered will update when it arrives tomorrow

[Kenny]

Up and running! Wired a direct earth from the CTS to the earth on the battery and up she lit, just need trace it back to the ECU to try and find it

[Kenny]

New ECU sorted the fault permanently, the bodged earth wire was temporary, thanks for your help anyhow

[Taurus]

Glad it's sorted. Sod's law says that the ECU survived the spike and then decided to randomly die on you. Thanks for telling us the outcome.

[Kenny]