Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: razzo on 03 March 2018, 16:42:26

Title: Non starter
Post by: razzo on 03 March 2018, 16:42:26
Any advice on where to go next, engine spins but won’t fire. No fault codes, swapped crank sensor for a known good one, descent spark at plugs, fuel pump fuses ok, only thing not checked is immobiliser but everything else seems in order, any advice on where to look next would be most helpful, it’s a 97 3.0
Title: Re: Non starter
Post by: Nick W on 03 March 2018, 16:55:19
How and when did you last use it? Was it started and turned off very soon after?


If you have a spark then it can't be an immobiliser fault.
Title: Re: Non starter
Post by: razzo on 03 March 2018, 17:10:15
Started yesterday morning & ran fine, switched it off after 15 mins & won’t fire up now
Title: Re: Non starter
Post by: Nick W on 03 March 2018, 17:25:07
Started yesterday morning & ran fine, switched it off after 15 mins & won’t fire up now


If you have a spark, then both the immobiliser and crank sensor are OK.


So there's a very good chance You've flooded it.
Ensure that the battery is fully charged, remove the fuel pump fuse, and depressurise the fuel rail using the test port. Now with the throttle fully open, crank the engine on the starter for about 30 seconds, or until it starts to slow down. Do this at least twice. Then refit the fuse and turn the ignition on and off a couple of times to reprime the system. Then try to start it normally.


If this works, drive it for several kilometres before turning it off again.


My experience of these cars is that they take forever to warm up if just left idling -  after 15 minutes idling, the temp needle has barely moved, and that's with a good thermostat.
Title: Re: Non starter
Post by: Andy B on 03 March 2018, 17:34:57
.....
If this works, drive it for several kilometres before turning it off again.
.....

How will you know how far you've driven when you'r speedo and odometer reads in miles? ::)

Doesn't the fuel get shut off on a wide open throttle anyway without pulling fuses?  :-\
Title: Re: Non starter
Post by: Doctor Gollum on 03 March 2018, 18:04:09
Only on dbw cars iirc...

Does the fuel pump prime when you initially turn the ignition on?
Title: Re: Non starter
Post by: Nick W on 03 March 2018, 18:50:14
.....
If this works, drive it for several kilometres before turning it off again.
.....

How will you know how far you've driven when you'r speedo and odometer reads in miles? ::)

Doesn't the fuel get shut off on a wide open throttle anyway without pulling fuses?  :-\


It should. But I've tried the official Flood clear procedure too many times on too many cars to have any faith in it. When you've other jobs waiting, you want as much chance of success as possible. Early V8 Jags and most I6 BMWs are particularly difficult. Micras are a different matter; with a bit of practice you can stick the fuse back in the moment it coughs and tries to start, and it will actually start.
Title: Re: Non starter
Post by: BazaJT on 03 March 2018, 18:59:26
My 6cyl X300 would flood if shut down shortly after a cold start,but could be re-started by using the "decking" the accelerator pedal and turning it over on the starter,I believe all the XJ6s were the same.
Title: Re: Non starter
Post by: Andy B on 03 March 2018, 20:27:09
.....
If this works, drive it for several kilometres before turning it off again.
.....

How will you know how far you've driven when you'r speedo and odometer reads in miles? ::)

Doesn't the fuel get shut off on a wide open throttle anyway without pulling fuses?  :-\


It should. But I've tried the official Flood clear procedure too many times on too many cars to have any faith in it. When you've other jobs waiting, you want as much chance of success as possible. Early V8 Jags and most I6 BMWs are particularly difficult. Micras are a different matter; with a bit of practice you can stick the fuse back in the moment it coughs and tries to start, and it will actually start.

Ta 👍
Title: Re: Non starter
Post by: razzo on 04 March 2018, 17:29:28
Listened under the fuel tank & nothing so starting to suspect fuel pump, also disconnected fuel hoses under plenum near the servo, cranked it & not even a dribble. So before I condem the pump is there any way of testing the purple relays or pump before I rip it all apart, fuses seem ok
Title: Re: Non starter
Post by: cam.in.head on 04 March 2018, 17:42:06
Swapping the two identical purple relay doest test them as such but would prove one faulty if you now have fuel .if i were you i would stick a voltmeter on fuel pump or test bulb and see if it is getting power .relay can be opened up and checked for burnt contacts or open circuit coil if need be or just replace.
Title: Re: Non starter
Post by: Kevin Wood on 05 March 2018, 09:40:19
If you open up the relay you can plug it in without the case fitted and then manually press the armature of the relay to make the contact. You can then verify that fuel issues from the pump.

I believe the non-DBW V6s don't prime the fuel pump, so if the crank sensor is faulty, you won't get any fuel pump activity at all, and if it isn't, you will only get fuel while cranking.
Title: Re: Non starter
Post by: Doctor Gollum on 05 March 2018, 12:17:38
Effectively the opposite of Dbw cars then :-\
Title: Re: Non starter
Post by: Kevin Wood on 05 March 2018, 12:37:21
Effectively the opposite of Dbw cars then :-\

DBW cars have the same behaviour, with the exception that you get a couple of seconds of fuel pump when you turn the ignition on to prime it.
Title: Re: Non starter
Post by: razzo on 05 March 2018, 13:18:58
Tested relays, they seem ok, swapped relays with known working one & still no joy. Wondering if it’s possible to test pump direct from battery & if anyone has done it?
Title: Re: Non starter
Post by: Doctor Gollum on 05 March 2018, 13:53:04
Tested relays, they seem ok, swapped relays with known working one & still no joy. Wondering if it’s possible to test pump direct from battery & if anyone has done it?
Yes, and yes...

Just need two 5m lengths of wire :y
Title: Re: Non starter
Post by: Kevin Wood on 05 March 2018, 15:28:37
Easier to just bridge to two contacts in the relay socket up front (the two wider pins on the relay are the contacts).

If fuel pump then runs, happy days. If it doesn't, check for 12V at the connector on top of the tank using a multimeter. If it's not there, it's the fuse or a wiring problem back to the tank. If it is, pump is FUBAR. :y
Title: Re: Non starter
Post by: Doctor Gollum on 05 March 2018, 18:52:21
True, but assumes that the wiring is sound...
Title: Re: Non starter
Post by: razzo on 06 March 2018, 10:34:25
Cheers for all the help chaps, pump connection has power but no life in the pump, sitting down with a large drink before I ring the dealer. If anyone has delved into this area any tips would be much appreciated & book of lies only gives it 3 spanner’s so can’t be that hard can it?
Title: Re: Non starter
Post by: Nick W on 06 March 2018, 10:49:47
Cheers for all the help chaps, pump connection has power but no life in the pump, sitting down with a large drink before I ring the dealer. If anyone has delved into this area any tips would be much appreciated & book of lies only gives it 3 spanner’s so can’t be that hard can it?


New in-tank fuel pumps are readily available from about £30 upwards. You do have to fit it to the swirlpot, but that's not the difficult part - undoing the plastic nut that holds it to the tank without breaking anything can be tricky.
Title: Re: Non starter
Post by: razzo on 07 March 2018, 19:55:25
Pump all sorted, magic carpet ride restored & for once SWMBO is in a good mood cheers all  :y
Title: Re: Non starter
Post by: Shackeng on 07 March 2018, 20:02:08
My 6cyl X300 would flood if shut down shortly after a cold start,but could be re-started by using the "decking" the accelerator pedal and turning it over on the starter,I believe all the XJ6s were the same.

I overcame this by fitting an isolation switch in the fuel line on my 4.2. :y