Intermittent Slightly Sluggish Start 1.8T
 

Very unusually for my runabout, these last few weeks I have been experiencing a sluggish start before the engine catches when the engine is cold. This occurs in very low outside temp and when relatively warm, perhaps 1 in 6 start ups are sluggish.

The engine runs perfectly right up to the redline once running. Excellent fuel pressure reading (not backed off or extruded elastomer at the filter housing) at shraeder valve and before the inlet manifold.

Initially I thought it was the fuel pump relay, due to my perceived lack of prime when turning the engine to ignition switch to position II, but it turns out I was getting prime. I changed the fuel pump relay out as a matter of course but this has made no perceivable difference.

I have not run T4 diagnostics yet, but now I am focusing on the cam or crank sensor. Anybody have any comments on this scenario?

I had a similar scenario with my 45 in very cold weather. I was in the habit of letting the fuel run very low before filling up. On occasions it struggled to start and it briefly brought the EML on. I took a fault code reading and it came back as fuel starvation and misfire on 3. I put a new set of plugs in and made sure I didn't let the tank run so low and haven't had a problem since.

I run the tank until the gauge is close to empty on all my 75’s and never had an issue of fuel supply to date. However the scenario occurs whether full or empty.

Would have thought it was quite normal in the cold weather tbh.


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In the most extreme cold days (we get lots of them up here) it starts on the button exactly the same as on a hot day.
Every now and again I get a little delay before it fires up independent of whether it is cold or hot outside temperature.

Sluggish starts ???----You've not mentioned the battery.


Bit low on charge ???

Needs at least 12.8 volts for a fast start. Multi-meter time.---:D

The motor turns over as fast as ever, it just needs a fraction of a second more to start to my ear, and something is going. It never failed to start in the recent minus temps we had constantly up here for some weeks. However I agree a good battery can make all the difference, and you may be right :shrug: The battery is some years old and this may be a factor.

12.1v this morning so a new battery it is then. :}

Pleased to have seen this post - my car has been slightly hesitant on startup - nothing on OBD - so just been out with the multimeter - and it reads 12.10 -12.11 - so a new battery - a bit miffed as the battery is a Varta and only just over 2 years old.:shrug:

Inlet manifold gasket leak comes to mind. Any misfire and white smoke on start up? Things usually clear once the engine warms and the coolant is expelled from the cylinder/s.:shrug:

It has a vvc manifold, and not a drop of coolant is used. It’s not juddering or anything like that. It runs beautifully, just a subtle tiny bit more cranking before it fires up from a cold engine. No fault codes and good realtime data from T4.

Will see how things go when I purchase another battery. This one only lasted 8 years :D

DON'T GIVE UP ON IT BEFORE YOU GIVE IT AT LEAST A 24 HOUR CHARGE.:D

Maybe that will work as a tonic for it. Leave it a few hours after charging for it to settle and then it will give you an accurate figure as to voltage.---:D

This time of year will highlight a battery on its last legs.

I did a 40 mile journey yesterday - should this not charge the battery up to 12.8 volts?:shrug:

Should still be under warranty Martin.

Battery’s usually are only guaranteed for 2 years anyway,well most of em Anyway.


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NO, not a chance.

For sake of argument let's say that 40 mile journey took an hour. ( @ 40 mph. )--That would equate to ONE HOUR on a charger !!!

Batteries on petrol engine cars need 24 hours on a charger.

Diesel 30 hours if in both cases the batteries start as flat ( Discharged. )

An alternator is regulated and charges a battery at roughly the same rate as a mains charger.

Example.---24 hours charge on a petrol car means driving for 24 hours at, lets say 30 mpg, at £7.00 a gallon.
Cost--£7.00 times 24 = £168.00---:eek::eek::eek:----Distance covered 720 miles-

Over night on a charger = £1.00 maybe.--:shrug:

All that driving would give you a headache through lack of sleep.---:D:D:D




Colvert.

Hello Andy - It has a 5 year warranty - from the RAC - checked the invoice fitted 2 years ago last week - so should it be giving a resting charge of 12.1 when it so relatively new. Will try the 24 hour charge and see.:shrug:

Did my post above help you at all ???



PS. 12.1 volts at rest.--Either discharged or dead.---:eek::eek::eek:

PPS. Your battery will only last FIVE years if it has been charged properly.---:duh:

She charged up to 12.65 at rest - smart charger then said fully charged - 4 hours later back to 12.35 volts so not holding charge -will check today again. So a duff battery or possibly the alternator not working properly:shrug:

But under load the battery gave 14.1 which seems OK.

Smart chargers are not to be believed when they say the battery is fully charged.

And the reason why is---------For sake of argument let's say your battery has only half of its plates working. ( The rest are coated with hard Sulphate. ) Your charger will tell you the battery is fully charged when, in truth, it's only half charged. The charger simply checks VOLTAGE, not CAPACITY.---:eek:

However a smart charger can give you a guide to the condition of the plates in your battery.

If your battery is so discharged it will only light a bulb, dimly and after a couple of hours charging your charger say FULL, you will know your battery is near the end of its useful life.

For more on this go to the Really, Really useful thread near the top of the main forum page and read a bit more about battery care. I've put more info in a couple of posts in there.

RAC came out and checked the battery, starter motor and alternator -all fine. Also no OBD codes.

However he detected a 0.6 amperes battery drain -equivalent he said to a small light draining the battery .

Will open a specific thread to see if anyone has any experience of something similar.

Did the test for failing alternator diode as per Google search- ie set multimeter to AC voltage and run the engine - if the diodes are OK there should be no AC going from the alternator into the battery or so I am given to understand - well am getting a reading of 30 AC volts which seems to point to diode failure which could explain battery drain :shrug:

Yet RAC man and his test says the alternator is fine.:shrug:

Just curious but how did you connect the multi-meter up??

From where to where and did you disconnect any wires ??

Hi -Set multimeter to AC Voltage lower setting- V wavy line - switched engine on - and black multimeter contact to the neg battery terminal and the red contact to the red pos post on the battery - it then gave 29-30 AC volts. Should it be done differently?

How'do Gary :)

how much of a spark plug gap are you running ?

I'm assuming it will be reduced from MG/Rover 1.0mm spec - reducing the Gap having a positive affect under full throttle with max boost pressure - could it have a slightly negative affect on start up ignition ? :shrug: just a thought ;)



Paul.

Hi Paul, I hope your machine is settling in now and chalking up the miles?

I’m running on .6mm gap. I haven’t seen any staring difference with 1.0 or .6mm tbh. Worth a shout at least, I think my battery is on its last legs.

:cool: My Car has been Great - the Engine work and New Front Suspension have Given the Car a whole new lease of life - unfortunately I'm not driving the Car daily as i have a pickup with my current job - I have been making a point of taking her for a Good run on the weekends though :cool:


I initially had issues with a standard 1.0mm Gap - slight misfire breakup with full throttle high boost acceleration - reduced to 0.75 (if i remember correct) then down to 0.60mm after i fitted my VVC Alloy Inlet Manifold, as i experienced the same breakup issue.

on a side note.... I'm still convinced fitting the VVC manifold had a positive(?) affect on the Boost :shrug: I know the port mismatch between manifold/head would suggest a negative impact on airflow/performance - However, i haven't checked to verify, but I'm sure the VVC has a larger volume plenum and with the map sensor located on the Plenum - all the differences will have some affect on the airflow/pressure and performance :shrug: but is it positive or negative ? I've had a max 15psi reading from my mechanical boost gauge reading direct from the spare vacuum port on the VVC Manifold (generally peaks around 12psi)... not sure what the max boost should expect to read :shrug:....... regardless, the VVC Inlet Manifold is still better :D



Paul.