Car Hesitating

Hi i recently came into possession of a micra (its branded as MARCH) k12 (branded as AK12). After driving it a few days i notice that it sometimes hesitate when upshifting, fail to pick up speed although flooring it, and idles roughly when at rest. Unfortunately the problem is very intermittent and temporary so i havent been able to have a mechanic witness it. I have had an electronic scan done (with an AUTEL MAXIDAS) but it didnt trip any code. I have had the spark plugs changed to new iridium ones, the oil and oil filter was changed. I have also had some injector cleaner added to the fuel mixture. But the intermittent problem still persists. Does any body have any suggestion on what might be the propblem or the sequence of checks i would need to go through.
 

John_D

Club Member
Radio Code Guru
Sounds like a throttle body fault, possibly dirty MAF sensor. Cleaning the throttle body may solve the problem but when I had a similar fault on my Saab, cleaning was only a temporary cure, a new throttle body was needed to give a permanent fix.....
 
OP
OP
L
Thanks John. Will see if cleaning it works.
Update: While looking at the engine cover i noticed one of the wires to one of the electrical connectors (top one in lue) is broken. Do you have an idea what this connector controls?
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John_D

Club Member
Radio Code Guru
That is the solenoid purge valve and is almost certainly the cause of your problems. Remake the connection and the purge valve will work again ......
 
OP
OP
L
That is the solenoid purge valve and is almost certainly the cause of your problems. Remake the connection and the purge valve will work again ......
Hi there. Well i had the connector removed and pulled out the pin and soldered it back to the main wire (it was too short for an on spot repair). Then in junctioned the whole thing back in and isolated it with some silicone seal sealing tape. An initial test drive didnt show the hesitation fault i used to get, thus i think it solved the problem. But as it is an intermittent and transitory problem, i will only be able to confirm after driving the car for a few weeks.
However, i noticed my resting/ idling rpm have increased i used to idle around 200 rpm not its at about 600rpm (sometimes it gets to around 400rpm and others at 800rpm but mostly 600rpm). Is this the normal range was my previous faulty rpm due to the faulty EVAP connection?
Am sorry if am asking dumb questions buit this is my first car, an unfortunately it doesnt seem like a very well maintained one.
 

John_D

Club Member
Radio Code Guru
Well on the K12 1.2 the idle at cold is about 1200 rpm but as the engine warms up drops to a fairly steady 7-800rpm....
As said above, get a code reader, they are only about a tenner on ebay, and see what comes up, also gives you the ability to re-set any codes stored. Not all fault codes trigger a CEL .
 
On my Micra i always habe to check that the ventilation fan is on. If the fan is off the idle rpm it decreses 200 rpm to about 600. When I put the fan on I see an increase on idle rpm. Normally it should remain stable to about 800 rpm. If you still have fluctuations in the idle rpm and you lose some "engine power" it is probably the begining of the chain issue.

Sent from my W_C800 using Micra Sports Club mobile app
 
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