Corsa-b running rough and wanting to stall

[darrensailes]

I hope someone can help cos this has been going on for some time now and no one so far has been able to say whats wrong, not even the local Vauxhall dealership!!! No ones diagnostics machine will work on my car. I took my car to the dealership yesterday and they said they dont know whats wrong with it but think it might be the EGR valve and wanted £370+ to replace it. I went and bought one brand new myself and installed it this morning but has made no difference. The problem im having is my car is wanting to stall when i stop at junctions and roundabouts, but its not happening everytime and now and again its able to rescue itself but the car is drinking more fuel and the sparks only being a month old and done 50 ish miles are already jet black, the engine light does come on each time i start the engine, but only for a short while. I have tired cleaning the idle control valve and anything else i can get to with carbarettor cleaner, ive also tried disconnecting the plugs one by one to see if that makes any difference but to no avail. Also my engine sounds a little 'chatty' I have checked my oil level and it is well within the lines I have a corsa-B 1.4 16v X14XE. Please help!!

[nath2905]

it sound just like the spark plugs, are they cheap 1s u put in it?
i'd only use NGK
and has it got the right oil in if they are black already?
just an idea m8, im nt the best with mechaning tho

or try this
http://forums.corsa-b.co.uk/viewtopic.php?f=105&t=11231

[darrensailes]

Cheers for getting back, that might be helpful, will try it out very shortly. The sparks were expensive ones, costing £20 for 4 at trade price!! I serviced the car in Feb when i did the head gasket and used the same type oil as last time. There was a clear 2/3 weeks between doing the gasket and this new problem arrising so i think its unlikely that the two are related.

[darrensailes]

Right, Ive done the paper clip test on my corsa and the following has arrisen:-
61 - Fuel Tank Vent Valve-Low Voltage
18 - Knock Control Processor
35 - Idle Stepper Motor Poor or No Idle Speed Control
15 - Coolant Temperature Sensor-High Voltage
33 - Manifold Absolute Pressure-High Voltage

Could anyone tell me what this means, whats causing it and how to fix it please

[Timmy corsa B]

if you turn the ignition on and push the valve in on the idle control valve does the motor work you should here it when the magnet brings it back out ?
maybe the mass air flow meter if its running that rich to turn the plugs black or i may be completely wrong here but possibly the oxygen sensor (lambda sensor) that me be worth a try i suppose whats it like when the engine gets up to tempreature?

[darrensailes]

The engine is no different hot or cold. how can i tell if the motor is working on the idle control valve, what sort of noise is it? I thought about the lambda sensor but again, how can i test it? also how can i find out whats causing the high/low voltage problems?

[Octane2097]

in order to test your sensors you will need a multimeter to measure the voltage or resistance of the sensors
high or low voltage problems is usualy just means the sensor is faulty there wont be anything causing it, probably just worn out
as for black plugs could be its running too rich, probably due to a fault sensor somwhere.

does sound like the idle control valve. sounds like thats whats causing your stuttering stalling problems
plus its there on the fault codes you got up
code 35
see the FAQ section for instrictions on cleaning/repairing the idle control valve.

as for the rest of the faults:

Knock Sensor

the knock sensor is located under here:



and should look somthing like this:



try cleaning the metal contacts (or test with a multimeter) if not replace it
(BTW refitting the knock sensor requires tightning to 13nm if this is incorrect it may not fuction properly and reduce engine power)
about £15 for a new one

MAP Sensor

should be located on the scuttle pannel near the coolant header tank, should have a vaccum pipe comming from it
should look like:



try giving the contacts on the wiring plug a clean if not it may want replacing.
about £20-30 for a new one

Coolant Temp Sensor

located bottom left on the engine:



under the radiator pipe highlighted, try removing and replacing, be careful tho as coolant will probably come out!
about £20 for a new one

as for the fuel tank vent valve, its attached to the carbon canister usualy located in the engine bay but not 100% sure where on the x14xe
on my 1.0i it was located infront of the nearside wheel well inside the engine bay. this could also cause running problems as your car is unable to vent fuel vapor from the tank.

[Octane2097]

hope all this helps bud

[darrensailes]

Thank you so much for getting back to me, I will do what you sudgested tomorrow and will post my results. The pictures of the items will help greatly, many thanks bro

[Octane2097]

no worries just hope u can get it sorted,
go for the idle control valve first, thats the most common problem with corsa running like a bag of spanners.

[darrensailes]

right well heres the latest.
I went and got a throttle (as my one kept sticking), idle valve and MAP sensor from a breakers yard and a new coolant temperature sensor, started up the car (DRUM ROLL PLEASE!!).................and it still runs like s**t. The paper clip test on the diagnostics plug is still showing the same faults, however twice i got a klunk from the engine somewhere but it is able to hold its revs better. Im starting to worry that my ECU is on its way out or somin :-S

[Octane2097]

the faults will still stay on as it saves them on the ecu, you will need them resetting
im not sure if you can erase the error codes without a diagnostic reader but have read on other forums if you swich the ignition on and off 25times it resets it

have also read if you have replaced any sensors you need to recalibrate the ecu to the new sensors, aparntly to do this you need to disconnect the battery overnight, then in the morning when you connect it back up before driving off let it idle for about 5 to 10 mins, then take it for a spin, using all the gears and revving freely.

againt not sure how accurate this information is but could always give it a try, it wont hurt anything or cost anything then once done try the paperclip test again see if you getting any faults

[darrensailes]

right, ok ive disconnected the battery then went down to the pub, but not before trying the ignition on/off 25 times trick. Unfortunately it did nothing! So any other ideas as to how to reset the ECU to accept different sensors? I shall still do the second part that OCTAIN2097 sugested tomorrow morning (ish) and see what happens, I am willing to try anything! even creating a voodoo type witchcraft spell to make the damn thing work perfect once more!!!

[matty101]

DISSCONNECTING THE BATTERY DOES NOT RESET THE ECU!!!

heres the proof..........

i was having poo loads of problems with my car so replaced sensors like maf, icv and the egr valve and disconnected the battery after changing each part like recomened by so many site and forums say u shud. none of this helped and i was still having the same problem so i took it to a garage to put it on a diognostic machine.

came back when they were done and the read out said there was poo loads of fault codes from when i changed the sensors. "but i reset the ecu by disconnecting the battery" i said the mechanic jst laffed and said that they had reset the properly and all the fault codes were gone.

now 99% sure wot the problem is and will be sorted once i get some time and money.

[Octane2097]

yea had a bit more time to do a bit of digging and matty101 is correct it cannot be reset with disconnecting the battery, as i said i wasnt sure it would work anyways.
according to a leading publisher of automotive technical manuals the only way to reset fault codes and learned values is with diagnostic equiptment
yellow pages under crypton tuning probably be around £25 for it doing unless you know someone.