I have a 2002 1,0 Activ with 72000 miles. Recently the car wont start first time, I have to put my foot on the accelerator and turn the key two or three times. If I don't accelerate the car wont start no matter how many turns of the key. Once the car starts it runs fine, no idle problems or stalling however fuel consumption is crap averaging around 270 miles from full to into the red before light comes on. Also just had new clutch fitted (not that that should make any difference) but the problem wasn't there before that. It has just past emissions test on MOT also. Any ideas would be gratefully accepted.
Cold start problems
- Thread starter jez105
- Start date
Sounds like it may be over fuelling at startup. Pressing the accelerator fully is the fix for starting a flooded engine. You could check the 2 wire temp sensor on the right hand side of the engine. The 2 wire one goes to the ecu for temp/fuelling. The 1 wire one goes to your temp dial on the dash. Does it start fine when fully cold the engine?
skymera
Brutal Honesty
I wouldn't have thought that would affect cold start up?
I thought a faulty temp sensor overfuelled when warm.
You're right it doesn't. He doesn't state though if it starts ok when cold. Once he gives a bit more info we can dig a little deeper.
Thanks for the replies, the colder it is the harder the car is to start. Regarding the clutch fitters I would not go anywhere near them again I took the car back after two days as the clutch cable snapped so I took one off my donor car and fitted it and had to adjust it fully so I could engage gears, the one that snapped was also adjusted fully and there answer to that was they used a Nissan Note 1.6 clutch and not to worry they would heat the bracket that holds the cable and bend it back to give me some more on the cable!!!! I will check the two wires as described by Agent Sm1th in the morning and report back. THANKS GUYS
Checked all wires and vacuum hoses and all are ok, but the sensor on the timing chain cover when i unplug it nothing happens the car still runs, is that meant to happen?. Also the car bumps straight away and runs normal but still won't star off key. I changed the plugs today and fitted Bosch Super 4 plugs, the ones i took out were black and all sooted instead of a brown colour. Any idea guys? thanks
pollyp
Club Member
looking at ur symptoms, here's afew thoughts:
Enrichment --------------------------------------------------------------------------
Cold crank enrichment vs running cold enrichment - coolant temp
you mention it push starts fine vs crank starting.
when the starter is engaged, the ECU is told to run a crank enrichment table which might add extra fuel depending on detected temperature.
if the cold fuel trim of a running engine was running way too rich close to flooding, the addition of too much crank enrichment from a faulty coolant sensor might be enough to flood it.
Idle speed too low --------------------------------------------------------------------
Fast idle waxstat: on pre-face engines there's a thermostatic coolant driven fast idle mechanism originally meant to open the throttle slightly below 82c to fast idle but the waxstat tends to seize, stuck in fast idle so most ppl end up closing the idle bleed screw as a bandage fix to slow it down.
The cold fast idle is also done by the IACV. Remedy for a stuck fast idle is to remove the waxstat mechanism to stop it keeping the butterfly open and let the IACV do the same job.
The facelifts don't have waxstats so ignore this.
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256
IACV: the idle air control valve controls the fast idle electronically.
normally when the ECU detects the coolant sensor is cold and is cranking, it fully opens the IACV to raise the idle speed. after cranking and running, the iacv would remain open till the temps reach 82c then closes.
if the iacv is sluggish or seized or miscalibrated, then it won't reach fast idle fast enough or even at all during cranking so there's no enough air to get the engine running. a seized iacv causes the engine to cold idle slowly then rises up once warm. remove and flush clean the valve with brake/carb cleaner, optionally calibrate it.
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256
Combustion Efficiency --------------------------------------------------------------------------
Timing: coilpack facelifts won't apply here. Matching the ecu timing to the crank timing via the dizzy on a preface is important to ensure it fires efficiently and also effects idle speed as a result. when the dizzy timing is wayy off, it might not fire efficiently enough during cold start to get the engine going.
Dizzy cap: coilpack facelifts won't apply here. a strong spark is essential for good combustion, especially during cold starts. the 4 contact points in the dizzy cap tends to build up oxide which increases resistance and weakens the spark, making cold starts harder. so remove and wirebrush the oxide off the points.
MPG issue -----------------------------------------------------------------------------------------------
Closed loop O2: the lamda sensor should heatup and get the ecu to closed loop asap to get it running at a economic 14.7afr
if the O2 doesn't heat up fast enough, the ecu ends up running a rich open-loop more often which wastes fuel.
if the O2 is sluggish or faulty, the ecu fuel trim and AFR will be wayy off and again wastes fuel.
Brakes: check for binding brakes
Tyres: check they're inflated
Alignment: check the wheel toe in/out isn't excessive which could cause alot of scrubbing which increases rolling resistance, wasting fuel and tyres
Enrichment --------------------------------------------------------------------------
Cold crank enrichment vs running cold enrichment - coolant temp
you mention it push starts fine vs crank starting.
when the starter is engaged, the ECU is told to run a crank enrichment table which might add extra fuel depending on detected temperature.
if the cold fuel trim of a running engine was running way too rich close to flooding, the addition of too much crank enrichment from a faulty coolant sensor might be enough to flood it.
Idle speed too low --------------------------------------------------------------------
Fast idle waxstat: on pre-face engines there's a thermostatic coolant driven fast idle mechanism originally meant to open the throttle slightly below 82c to fast idle but the waxstat tends to seize, stuck in fast idle so most ppl end up closing the idle bleed screw as a bandage fix to slow it down.
The cold fast idle is also done by the IACV. Remedy for a stuck fast idle is to remove the waxstat mechanism to stop it keeping the butterfly open and let the IACV do the same job.
The facelifts don't have waxstats so ignore this.
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256
IACV: the idle air control valve controls the fast idle electronically.
normally when the ECU detects the coolant sensor is cold and is cranking, it fully opens the IACV to raise the idle speed. after cranking and running, the iacv would remain open till the temps reach 82c then closes.
if the iacv is sluggish or seized or miscalibrated, then it won't reach fast idle fast enough or even at all during cranking so there's no enough air to get the engine running. a seized iacv causes the engine to cold idle slowly then rises up once warm. remove and flush clean the valve with brake/carb cleaner, optionally calibrate it.
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256
Combustion Efficiency --------------------------------------------------------------------------
Timing: coilpack facelifts won't apply here. Matching the ecu timing to the crank timing via the dizzy on a preface is important to ensure it fires efficiently and also effects idle speed as a result. when the dizzy timing is wayy off, it might not fire efficiently enough during cold start to get the engine going.
Dizzy cap: coilpack facelifts won't apply here. a strong spark is essential for good combustion, especially during cold starts. the 4 contact points in the dizzy cap tends to build up oxide which increases resistance and weakens the spark, making cold starts harder. so remove and wirebrush the oxide off the points.
MPG issue -----------------------------------------------------------------------------------------------
Closed loop O2: the lamda sensor should heatup and get the ecu to closed loop asap to get it running at a economic 14.7afr
if the O2 doesn't heat up fast enough, the ecu ends up running a rich open-loop more often which wastes fuel.
if the O2 is sluggish or faulty, the ecu fuel trim and AFR will be wayy off and again wastes fuel.
Brakes: check for binding brakes
Tyres: check they're inflated
Alignment: check the wheel toe in/out isn't excessive which could cause alot of scrubbing which increases rolling resistance, wasting fuel and tyres
