850 t5 difficult to start when cold

[Kingsford G]

Could that be immobolizer or ecu connection?

[960kg]

I would start at square one and make sure you have Volvo plugs fitted.

Premuim fuel is always harder to ignite when in a cold situation!

Seeing as your pump is new and the filter ok i would next go for the Engine Temperature Sensor £35
fitted under the thermostat in the block, if faulty you won`t get the correct amount of fuel whether hot or cold.

Yes you can change the FPR on the fuel rail but this usually causes bad hot starts and not cold ones as the diaphragm which faulters lets more fuel in
so an easy cold start but not so when hot. For a quick check on the condition of the FPR disconnect the vacuum pipe at the tree by the throttle housing going to the FPR
and smell the end or taste it or even blow and suck in it, if you sense petrol or no holding any pressure then the valve has gone and will need replacing.

With these problems you tend not to get a cel light or error codes.

Good Luck.

[merc85]

Could that be immobolizer or ecu connection?

Only has issues when cold, and the alarm has bin takern off

[merc85]

I would start at square one and make sure you have Volvo plugs fitted.

Premuim fuel is always harder to ignite when in a cold situation!

Seeing as your pump is new and the filter ok i would next go for the Engine Temperature Sensor £35
fitted under the thermostat in the block, if faulty you won`t get the correct amount of fuel whether hot or cold.

Yes you can change the FPR on the fuel rail but this usually causes bad hot starts and not cold ones as the diaphragm which faulters lets more fuel in
so an easy cold start but not so when hot. For a quick check on the condition of the FPR disconnect the vacuum pipe at the tree by the throttle housing going to the FPR
and smell the end or taste it or even blow and suck in it, if you sense petrol or no holding any pressure then the valve has gone and will need replacing.

With these problems you tend not to get a cel light or error codes.

Good Luck.

Thanks bud, the temp gauge is all good, so is the stat, plugs are good, Cap and Rotor are worn but surly it would miss fire when being driven or under load?

Goin to have a look at the injectors and FPR tonight, may fit cap n rotor.

Will check fuel lines by the tank as they all seem good at the engine.

[Kingsford G]

Would be good to have a fuel pressure gauge to diagnose the fuel supply good or bad.

[merc85]

Would be good to have a fuel pressure gauge to diagnose the fuel supply good or bad.

Havent got one im afraid

[nottsgreent5]

Mite sound abit strange but if you have a spare starter motor try that had a problem with a mates t5 few years ago changed all the sensors injectors the lot and that was doing similar to yours as i was clutching at straws i changed the starter just to rule it out an it cured the problem as to why i do not know lol

[merc85]

Update, Fuel Reg was faulty as i sucked on the vac line and got mouth full of petrol, changed it for a new one and Bit the bullet Bought a new cap and rotor, She fired up striagjht away, Yippie i thought, went for a short drive no miss fires or nowt, parked up went into a shop, came out 5 mins later turned the key and YES you guessed it simply wouldnt start, 30mins later she fired up! got her back home turn it off, try to start it Nothing, just turns over. Took a PLUG out and it had no spark then as i was cranking it the plug sparked and she started!

STILL NO CODES but seems now heat related, when she's hot doesnt start. NO SPARK NO CEL

Changed:
CAP
ROTOR
KNOCK SENSOR'S
CAM SESNOR
CRANK SENSOR
COIL AND MODULE
fuel reg
AND KING LEAD
Now thinking ECU, gonna try the ecu from the Gul and see if she still play's up, if she does it's getting broken.

[Kingsford G]

Don`t u dare to brake her

[merc85]

Don`t u dare to brake her

Trust me it will happen, Found a old bill in the "Service history 2005 mileage 108k" Engine cutting out Fault found to be wiring to ecu, Really thinking its a Ecu or Wiring to the ecu fault that being the case i'm going to break it.

[960kg]

Update, Fuel Reg was faulty as i sucked on the vac line and got mouth full of petrol, changed it for a new one and Bit the bullet Bought a new cap and rotor, She fired up striagjht away

Forgot to say beware about a mouthful of premium grade Ha! ha!

This is a quick useful check for the FPR....it must of been well gone and flooding the engine as usually they affect bad hot starts?

Did you replace with the correct brand new one from Volvo?... as if you didn`t a very small split in it may be still giving hot start probs. Just a shot....

[merc85]

Changed knock sensor, car diffinalty has a cam sensor / wiring /ecu fault, its ha s intermitant spark as soon as the plugs fire the car starts imediatly, but can take 30 cranks to make it spark!

Gonna try another ecu and check contnuity at cam sensor, looking like a breaker to me shame nice car.

[Harvey]

Battery voltage when starter running low ?.
Try starting car with jump leads connected to a second car engine running on second car.

[merc85]

Uprated bosch battery spins over easy

[960kg]

Just trying to help you not break it ....although this Vadis Bulletin for the 850 says a different engine it is still the 20 valve

Don`t forget it was written when the car was new!!

But as you replaced the engine with another known one that is good you don`t know how it was driven?

I am just clutching at straws for you but if it`s in the Volvo bulletin sheet then it must be real.....

Of course although it states Champion plugs i expect now in 2012 the exact Volvo plug for this engine should be used to avoid problems.

[Jamest5r]

Ok as your into the the long shot territory here's one for you, check the connectors between the cam and crank sensors, it may well be that the connections on the loom side are faulty so no matter how many cam/crank sensors you change you will always have the same fault, this happened to me and took a looooong time to work out, i cut the faulty connector off the loom and wired one from a scrap car and fired 1st time everytime.

[960kg]

Uprated bosch battery spins over easy

Linked to my previous post about the carbon etc. in a not known engine you replaced with......

One common cause of non starting with the 960 if it has been just local drives, shopping car, is the carbon build up on the valve stems
and this stops the valves closing properly so lower compression and non starting when cold with the engine spinning endlessly.

This 6 cylinder engine is the same white block as ours so the same problems will apply.

People talk of the "Italian Tune up" and think that it just means ragging the poor engines nuts off but this is not the case
and is a real means to preventing problems.

The proper definition is to run the engine in the appropriate gear to give you 4500revs and run for 5 minutes, motorway is best, and at these revs the valves begin
to turn in there guides and this cleans them and does prevent them sticking due to carbon build up.

Also they recommend to use a 10W 40 oil on an older engine for better compression.

These are all readings that i have learnt through owning Volvo`s for the last 16/17 years so owners have had these type of problems to sort out.

I know all these things seem like myths but when you have done all to your motor and it still repels then perhaps some not so common procedures can be tried.

As Jamest5r said your in long shot territory, his one about the connector sounds a good chance.

[Kingsford G]

That engine is from Gavs old 855 and he rebuilt it port polishing the head.I can`t c any carbon built up in about 200 miles he done unless 1 night someone by mistake took a cr@p in his inlet pipe.

[960kg]

Needn`t of wasted my time then!

[stribo]

Needn`t of wasted my time then!

Hardly a waste of time mate, even if it's not applicable to Gav's problem, could be a big help to someone else with the same problem.