850 non starting self diagnosis - Page 2

dinky1 · Jan 24th, 2013, 17:31

Have you tried replacing the TDC sensor? - It's mounted on the side of the block on the top of the gearbox.

Luxobarge · Jan 24th, 2013, 17:37

Quote:

Originally Posted by dinky1

Have you tried replacing the TDC sensor? - It's mounted on the side of the block on the top of the gearbox.

It's not really a TDC sensor, it's a crank position sensor (CPS) often shortened to "crank sensor" - and he says he's already changed it.

Good thought though.

Merc85 · Jan 24th, 2013, 18:26

Thanks for everyones reply's

ive changed,

Cam Sensor,
Crank Sensor,
Knock Sensor's
Plugs
Cap
Rotor
Leads
Coil and module
Fuel Reg
Starter
Ecu
Tps
Cleanded earths
Re-wired trigger sendor to Coil
Hard wired Cam
Hard wired crank
Checked Fuel pump
Checked fuses
Replaced fuel pump relays
Injector relays
Temp sendor
Fan relays

Ran out if ideas. havent done the ignition switch. All my lights work etc when i turn the key. Car hasnt thrown any codes and plays up when the car is cold and worse when its been left a few days without starting.

Once the car has started its fine, but does stumble straight after starting again.

It doesnt missfire at all and idles fine. Performance is spot on. no vac leaks.

The car seems to take a little to long priming the fuel at the rail. I ran a Direct live to the + on the coil from the + on the battery, The pump primed but only a short time. the light all light up on the dash, upon cranking it didnt make any difference actually seemed worse once it started the lights went out as they should.

960kg · Jan 24th, 2013, 18:37

You should change this on the end of the ignition switch as they wear.

There is a plunger in the centre also that the switch pushes in so it may not be pushing enough to contact all the contacts if worn.

By the looks of your list you haven`t tried it!!

Merc85 · Jan 24th, 2013, 18:51

Quote:

Originally Posted by 960kg

You should change this on the end of the ignition switch as they wear.

There is a plunger in the centre also that the switch pushes in so it may not be pushing enough to contact all the contacts if worn.

By the looks of your list you haven`t tried it!!

Thanks bud, do you think it really could be that, and No your right i havent changed it.

mikealder · Jan 24th, 2013, 18:57

Quote:

Originally Posted by Merc85

Thanks bud, do you think it really could be that, and No your right i havent changed it.

Go back to page one of this thread and read post 9 where I suggested you should change the electrical portion of the ignition switch which is what 960KG is also suggesting, it fixed a near identical fault on my mates 850 last year - Mike

Merc85 · Jan 24th, 2013, 19:01

Quote:

Originally Posted by mikealder

Go back to page one of this thread and read post 9 where I suggested you should change the electrical portion of the ignition switch which is what 960KG is also suggesting, it fixed a near identical fault on my mates 850 last year - Mike

Sorry mike, apreciate you imput there, i didnt relise this could stop the coil from sparking,

Wouldnt having a direct live to the coil prove that this is not the fault?

If i'm wrong this will be my next thing to try.

ASt85 · Jan 24th, 2013, 19:14

How soon after you start the car do you turn it off? Do you raise the revs. before you turn off?

This type of starting problem can occur if the engine has lost compression due to petrol washing down the oil from the cylinder walls on higher mileage motors and can occur when/if either of the above are done.

My old 850 20VGLT had to be run for at least 2 minutes (oddly the time the service light stays alight) before switching off otherwise it would be 6/8 minute fast crank using a heavy duty VW transporter battery to re-establish compression - other solution was to inject 10/15ml of oil down each bore to get it going - bit smokey, but worked on the occasions when someone forgot the 2 minute thing.....

dinky1 · Jan 24th, 2013, 20:12

I can't help but wonder if this replacement coil might have packed up too. I had the engine out of the safrane a while back and never touched the coil. It went back in and refused to start for 14 months until we finally replaced the coil.. and it started instantly. The odd thing was we'd been seeing it spark when cranking too as we checked with the timing gun!

Merc85 · Jan 24th, 2013, 20:15

Engine is very strong and not long bin rebuilt, Injectors etc all tested fine.

Yeah could be coil, dont know really, just took the steering coloumn apart and the switch pack looks extremly good condition. looks fairly new tbh

Jan 24th, 2013, 17:31	#11
dinky1 Volvo lump in a renault!! Last Online: Jan 11th, 2024 18:06 Join Date: May 2010 Location: England	Have you tried replacing the TDC sensor? - It's mounted on the side of the block on the top of the gearbox. __________________ Renault Safrane 2.5 with the Volvo B5254FS 850 2.5 20v engine. It's the same block using Volvo parts but with a few 'adjustments'

Jan 24th, 2013, 18:26	#13
Merc85 Premier Member Last Online: Apr 19th, 2024 12:58 Join Date: Dec 2009 Location: Harwich	Thanks for everyones reply's ive changed, Cam Sensor, Crank Sensor, Knock Sensor's Plugs Cap Rotor Leads Coil and module Fuel Reg Starter Ecu Tps Cleanded earths Re-wired trigger sendor to Coil Hard wired Cam Hard wired crank Checked Fuel pump Checked fuses Replaced fuel pump relays Injector relays Temp sendor Fan relays Ran out if ideas. havent done the ignition switch. All my lights work etc when i turn the key. Car hasnt thrown any codes and plays up when the car is cold and worse when its been left a few days without starting. Once the car has started its fine, but does stumble straight after starting again. It doesnt missfire at all and idles fine. Performance is spot on. no vac leaks. The car seems to take a little to long priming the fuel at the rail. I ran a Direct live to the + on the coil from the + on the battery, The pump primed but only a short time. the light all light up on the dash, upon cranking it didnt make any difference actually seemed worse once it started the lights went out as they should. __________________ HLM304, Forge unos 17.5psi at 3.8 bar, 18t, Me7 Manifold, Blues, Walbro, De-cat, Ported n Polished Head, 3" Dp stainlesss exhaust, Carbon Air intake, Polly Bushed thoughout. Last edited by Merc85; Jan 24th, 2013 at 18:30.

Jan 24th, 2013, 19:14	#18
ASt85 Premier Member Last Online: Yesterday 13:07 Join Date: Aug 2010 Location: Walderslade....Kent	How soon after you start the car do you turn it off? Do you raise the revs. before you turn off? This type of starting problem can occur if the engine has lost compression due to petrol washing down the oil from the cylinder walls on higher mileage motors and can occur when/if either of the above are done. My old 850 20VGLT had to be run for at least 2 minutes (oddly the time the service light stays alight) before switching off otherwise it would be 6/8 minute fast crank using a heavy duty VW transporter battery to re-establish compression - other solution was to inject 10/15ml of oil down each bore to get it going - bit smokey, but worked on the occasions when someone forgot the 2 minute thing..... __________________ The saddest moment is when the one who gave you the best memories....becomes a MEMORY V70 SE 2004 2.3L T5 Geartronic, C70 2005 2.0T Automatic, Sold 2.4l 20 Valve Automatic Torslander Sold 854 GLT 20v Auto Last edited by ASt85; Jan 24th, 2013 at 19:22.

Jan 24th, 2013, 20:12	#19
dinky1 Volvo lump in a renault!! Last Online: Jan 11th, 2024 18:06 Join Date: May 2010 Location: England	I can't help but wonder if this replacement coil might have packed up too. I had the engine out of the safrane a while back and never touched the coil. It went back in and refused to start for 14 months until we finally replaced the coil.. and it started instantly. The odd thing was we'd been seeing it spark when cranking too as we checked with the timing gun! __________________ Renault Safrane 2.5 with the Volvo B5254FS 850 2.5 20v engine. It's the same block using Volvo parts but with a few 'adjustments'

Jan 24th, 2013, 20:15	#20
Merc85 Premier Member Last Online: Apr 19th, 2024 12:58 Join Date: Dec 2009 Location: Harwich	Engine is very strong and not long bin rebuilt, Injectors etc all tested fine. Yeah could be coil, dont know really, just took the steering coloumn apart and the switch pack looks extremly good condition. looks fairly new tbh __________________ HLM304, Forge unos 17.5psi at 3.8 bar, 18t, Me7 Manifold, Blues, Walbro, De-cat, Ported n Polished Head, 3" Dp stainlesss exhaust, Carbon Air intake, Polly Bushed thoughout.

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