Micra 1.5 DCi Cold start problem - Cranks okay hard to start

Hi good people. I am in need of some wise advice.

Nissan Micra diesel on 2003 plate. Not playing ball starting when cold. Have replaced battery for new and given it a full charge. Have replaced all 4 glow plugs as car is now on 150k. Two of these tested faulty anyhow.

Symptoms are:
Cranks for 9-sec in the morning fails to start. 2nd attempt crank another 9-15 secs and car starts and runs fine. Drives with no loss of power. Fuel economy fine.
Stop car and retry from hot cranks but hard to start again. Waits half an hour and car starts after 2-3 secs crank.

Observations:
Alternator producing 14.4v so car battery charging okay.

With ignition switched on. Glow plug indicator light comes on for 1 sec, for off for 5 secs, on for 1 sec..then repeats until car is started.
Voltage measured across battery drops from 12.7v to around 11.5v in sync with the glow plug dash light.
Power is measured at glow plug tip in sync with glow plug light , cannot hear any relay though.
Although it seems the glow plug relay where ever it is appears to be passing current. I have contacted dealership. Who have priced up for a glow plug relay timer and told me where it is located;) But cannot seem to find a glow plug relay and its location:) Another dealership suggested the glow plug relay is integrated with the IPDM (Intelligent Power Distribution Module) unit. Could this be the case -

Temp sensor appears to be working. Blue light displaying in dash when cold. out when temp normal. red when car hot (presumably)

This engine is from a Renault and on their forum these symptoms are almost always cured through replacement of a faulty cam sensor. However, nissan dealership parts are saying there is no cam sensor on the micra.

Words to the wise please.
 

frank

Club Member
i would have thought that the relay is untimed/generic, and that the ecu determines what time-dwell to apply ?
checking the signal to the relay would confirm eh :)
 

frank

Club Member
what i mean is does it fire up better if you light the glowplugs repeatedly ? (ign on and off a few times, then crank it, dont over do it btw !)
and knock yourself out on nissan4u searching :)
 
Makes no difference in that sense as the glow plugs only power up for a second at a time. So effectively I have no pre-heat at all. Ineed to find the glow plug relay itself so that I can manually force it on for 15 secs or so by applying a negative to the relays primary winding. If the car then starts on the key. I can then work backwards. Timer, ECU, sensors to ECU etc..
 

Attachments

  • IMG_0440.JPG
    IMG_0440.JPG
    1.5 MB · Views: 5,912

frank

Club Member
hmm, our works van would never fire up unless you gave it 2 or 3 squirts of the glowplug light (even if it only stopped on for 1 second) cant you trace the fat glowpug wire back to the relay ?
 
Have tested glow plug relay timer and it is checking out fine.

Process for others is documented below;

1) Connect Voltage Meter -ve lead to battery -ve terminal.
2) Connect Votage meter +ve lead to Glow wire from timer unit/glow plug relay having first removed it from one of the glow plugs. Make sure this wire does not touch the car body.
3) Watch the video to see what the voltage readings are once ignition is turned on!


4) Compare glow plug warning light time on/off with actual reading on the meter.
In this video the actual readings are from 1 minute 40 secs into the video till end of video on you tube.

No current to the glow plugs reading is 11.2volts. Whilst current is being supplied to the glow plugs the voltage drops by 0.3v to around 10.9volts. In this video the current is being supplied for around 16 secs in cycles. Showing that pre-heating 0-10secs and fixed heating 11-6 seconds is occurring. The circuit is normal and working.

Having done the above and if I now leave the car to pre-heat fr three cycles the micra starts much better after two cranks of three seconds each. However, it should start much much better so still some more analysis to do.

Next steps to check out coolant temp sensor, crank shaft sensor, and cam sensor. Results to follow...
 
May well be normal wear and tear at 147000 miles on the clock.
However today the care has leaked water from the water pump area and soon after it has stalled for the first time ever. Making a rattling noise. Typical of the when a timing belt has slipped and the tooth have jumped a cog. So before any other cranking is done the timing cover must come off to check top dead centre alignment. A big job which must wait for The weather.
Looks like I will now be doing the timing belt and water pump. Starting Sophia up and listening to see if all is well and if not checking for valve gear damage and repair and compression.
 
Top