Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Bionic]

Petrol pump relay - Anyone any idea which one it is?

Sometimes it starts and runs a bit then cuts out.
Sometimes it will not start.
Fuel pump working ok. (took out and tested)
Fuel Filter changed.
Crank sensor changed. (old one left in place ready to go back just in case)

Its doing my head in 

[Andy H]

Relay 20 according to the second image in http://www.omegaowners.com/forum/index.php?topic=90458.0 Engine bay relay box layout

(or K44 in the third image..............)

[Kevin Wood]

Right at the back of the engine bay relay box you'll see 2 purple relays. Fuel pump relay is the one furthest from the engine (closest to the passenger side wing).

If you get a short length of wire with a spade connector on each end, you can remove the relay and connect the thick pair of spade terminals in the relay base together (pin numbers 30 and 87). The fuel pump should then run continuously. You can try this when you get a failure to start and see if it helps.

While you're there, the main engine relay is the other purple relay. If it failed you'd probably get similar symptoms so might be worth checking that too.

[Kevin Wood]

Relay 20 according to the second image in http://www.omegaowners.com/forum/index.php?topic=90458.0 Engine bay relay box layout

(or K44 in the third image..............)

TIS suggests it's Number 10 from that picture (Y26SE/ Y32SE models though. Maybe it changed at some point?) so, for the avoidance of doubt, the following wire colours should feed the fuel pump relay:

Red
Black and green
Red and blue (thin. Engine relay has thick red and blue)
Brown

Just pop the relay holder out of the box and check the wiring colours.

Kevin

[Bionic]

Did as you suggested Kevin ans bridged the contacts out and it started straight up.
I then slackened the fuel delivery pipe nut and there was good delivery of petrol so I have left it running to see if it keeps going or does its usual trick 

I think now until I can get a new relay from VX I will fabricate a switched lead to do what the temporary bridge is doing so I can at least have some control over it. I have plenty of spade connectors and switches I can use - maybe even enougfh to get the switch inside the car 

Its been running for anout 5 mins now so I will put another post on after 30 minsd and hope it keeps going. If it does its down to the dealership I go.
Still love the miggy though - always will cos like a woman they can be as obstinate and arkward as all hell. 

AAAAARGH...The saga continues....Just as I was going to take a chance and go to the dealership it cut out again. Looks like it was not that relay then so back to the head scratching....

[Bionic]

Ok, Went back to it again and took off the fuel delivery line and put it where I could see the end. Turned the motor over and it spouted loads of petrol so my guess is that both the fuel pump aqnd the Crank Sensor are both working as they should. As I cannot vouch for the K44 relay I will leave it bridged out until I can get one.
In the meantime it still will not start so my next thoughts are that the DisPack is breaking down.
Is that a real possibility cos when it starts it runs smooth as ever with no misfires or hiccups at all?
Code reader shows no codes at all either.
Maybe I will have give DLK a bell..........

[Andy H]

Intermittent faults can be real time wasters 

Took me ages to trace an intermittent start problem on SWMBOs golf. By a process of elimination I discounted the inhibit switch and ignition switch and convinced myself it was a reassuringly expensive relay in the fusebox.

Fitted a new relay and it started first time , and second but not the third .

I eventually tracked it down to a broken wire from the loom to the starter solenoid...........

I suspect that your problem is something similar. Maybe a fractured fuse or loose connection somewhere

[Bionic]

DLK says to have ago at the egr valve which I will do later and blank the thing off. Way its acting it might well just be that too.

[Kevin Wood]

The thing with the coil pack (and injectors for that matter) is that there are 3 individual coils in the pack. To stall the engine at least 2 of them would have to fail at exactly the same time. The engine will keep idling on 4 cylinders (one failed coil).

So, we're looking for something common to all cylinders. Failed fuel supply would do it, but I think we've eliminated that. At any rate, we'd have a gradual decay in fuel pressure so I doubt it would cut dead (I assume that's what it's doing, or is it spluttering and misfiring for a bit then dying?).

Main relay (the other purple one) is worth eliminating if you can. Bridge the contacts exactly as you did for the FP relay, or swap the two over and see if the fault changes.

The 30A fusible link in the PDS fuse box on top of the battery runs all of the engine electronics, so check that and the wiring to it. Could be a loose connection.  Try waggling all the wiring in that area, down to the ECU and the loom that connects over to the engine. Might be an intermittent connection somewhere.

You could try disconnecting the MAF and leave it running to see if it still stalls. An MAF output that disappears suddenly might cause it to stall whereas with it disconnected the ECU will substitute a value and it'll run, albeit not that well.

Ditto the EGR valve. I'd expect it to stay closed at idle, however, if that sticks open it could cause a stall, ECU will moan if you disconnect it, but that will at least eliminate it.

ICV - could disconnect this and start the car by feathering the throttle to keep it running if required. I can't remember if the ICV closes if disconnected or opens. You will either get a fast idle or nothing, but keep the engine running with a little throttle if required and see if it stalls.

Also - don't neglect the obvious... Is the battery voltage OK? Not dropping too low or rising too high when running? Both could cause the ECU to shut down.

Another check for codes in the ECU might be worth a try...

[Bionic]

Thanx Kevin, Done all that nearly.
It does not peter out, it just stops and there is loads off fuel when the fuel line is cracked open.
Both relays you mention were bridged out. When I bridged out the one nearest to the engine there was a hissing from the plenum area. Could that be the problem - what could it be?
Fuel, like you say has well and truly now been elliminated as a cause - I stink of petrol after a shower in it from the main fuel line 
As it runs like a dream when running and has no hiccups or misfires at all I do not think it is the dispack.
If the 30A fuseable link you mention was blown it would surely affect the dash warning lights coming on or going off? They operate normally and then stay off. I will test it tomorrow though just in case.
DLK has told me to blank plate the EGR and I will be doing that in the morning. I will put it back to rights if it makes no difference though cos I like the car to be as original os possible.
I will aslo be receiving another couple of CS Sensors to try.
Battery voltage is ok and runs within limits.
No codes again after yet another OBDII session.
That only leaves the MAF - wherever that is.
Enlighten me if you can and I will do whatever it takes to see if it makes any difference.
  I must be a sucker for punishment 

[Kevin Wood]

When I bridged out the one nearest to the engine there was a hissing from the plenum area. Could that be the problem - what could it be?

Probably fuel circulating through the fuel pressure regulator. Nothing to worry about, IMHO.

If the 30A fuseable link you mention was blown it would surely affect the dash warning lights coming on or going off? They operate normally and then stay off. I will test it tomorrow though just in case.

This is true, was just wondering if there's a poor connection there, corroded fuse pins, etc. It only has to interrupt the current briefly to stop the engine.

DLK has told me to blank plate the EGR and I will be doing that in the morning. I will put it back to rights if it makes no difference though cos I like the car to be as original os possible.

Yep, worth a try.

Enlighten me if you can and I will do whatever it takes to see if it makes any difference.

It's just below the 90 degree elbow by the air filter, as the duct turns downwards. The larger of the two connectors is the MAF (smaller one is air temperature).

[Bionic]

  Got to get you a drink at one of the meets if ever I get there. Really hoping for the 2012 one.

After it has stood all night I bet that it will start straight up this morning before it starts its tricks. If so that would point I think to a heat sensitive problem, or would it?

I shall crack on today now I have unseized my aching bones and see where I go from there. Fusible links I shall remove and clean, in fact I will do them all. EGR is the next mark and as Steve is sending me another CS sensor from a runner which he had just got in and should arrive this morning that is next.
Daz too is sending me one from a known runner.
I would think that if they all fail to solve the problem then I can rule out the CS sensor....Until then I am becoming very rapid at doing these jobs, expert almost 
This problem is better than University Challenge! 

[Bionic]

  Started it without problems this morning as soon as it got light. It ran until it got to operating temperature (85) and then stopped. Is this now pointing to a sensor of some type, not just the CS one?
As always there was loads of fuel there when the fuel lines were cracked open.
In the meantime I am going ahead with my plans as in the previous post.

Never give up - some motto that is 

[Kevin Wood]

It does keep pointing to the crank sensor. They often fail when hot. 

[Bionic]

 
Ok Kevin,
This morning I have checked the air filter although I knew it was a new one I fitted a month ago.
EGR: took it off and it was clean inside, a little black was all but the inards moved freely so I gave it a quick brush up and put it back.

MAF: Took all hoses off and checked the electrical connectors. They were all nice and tight and all were clean inside. The MAF sensor itself was clean and bright anyway. I put the hoses back and reconnected the electrics.

FUSE BOX. Relays, fuses and fusable links links were all checked for security and loosness. No problems were found.
 
FUEL: As always there was loads of it when the pipe unions were cracked open.

I took off the windscreen scuttle then I checked all other connectors that I could see and particularly those at the back of the engine. All were secure and remarkably clean. There was no unconnected pipes or other connectors that I could see.

Here we go thinks I, time for a tryout. It started first crack and I let it run for a while and as soon as the cold choke came off I disconnected the MAF plug and allowed it to run for a while, then I unplugged the EGR and let it continue to run. It ran a bit rough as was expected and the EML light was lit on the dash (expected).
Just to be certain I did this test by starting with them firstly connected and then again with them disconnected. Same result!
It ran quite well but I had to jam the throttle open a little to keep it running. After about 15 mins running and reaching its usual running temperature it again just cut out without warning and would not start. I checked the fuel and as expected there was more than enough there. Being a bit issed off I went for a cuppa and after about 15 mins went to it and it started again as though nothing was amiss!
I have left it now until the other 2 CS sensors arrive probably tomorrow.
All I did after that was to re-route the CS sensor wire at the back of the engine under the Scuttle to more reachable position in readiness.
I will trickle charge the battery tonight to put back what it took out so its in top form again.

Who said life is like a bowl of cherries?

[albitz]

Agree with Kevin.Classic crank sensor symptoms.

[Kevin Wood]

Might be worth getting it running and then waggling the exposed parts of the crank sensor wiring, see if you can provoke a failure.

Still, with another couple of sensors to try, you should make some progress.

[Andy H]

Might be worth getting it running and then waggling the exposed parts of the crank sensor wiring, see if you can provoke a failure.

Still, with another couple of sensors to try, you should make some progress.

(If not crank sensor) is there anything else that could be similarly heat sensitive

[Bionic]

Ok, I will do the waggle test this morning and see if it has any effect but.....
Now the painful bit Being disabled I have to have it reliable again so.....
Just to cover all the bases I have just sent a request to both of the VX dealers in Leicester for the cost of an OEM CS Sensor. Until then I will try the ones which hopefully will arrive today. Trade club cost might be a great help on that one 
You have to give me credit for patience, perseverence (or is it stubborness) and the absolute refusal to be beaten though. Its looking like the meet I eventually do get to will cost me dray load of bevvy for my 'advisors' 

[Bionic]

  Just ordered a new CS Sensor and it was a lot cheaper than I thought. Its exactly the same as those supplied as OEM to the dealers so when it arrive tomoz I will get it put on and see what happens............
VX Part number for anyone who is interested is 90540743

[Bionic]

 
Fitted the new OEM CS Sensor and ran it for a good while then took it on the road for a long run. No problems at all so it then got a good clean ouitside and in!
Ran it yesterday all day and no problems so it would appear that the CS Sensor was the cause of the problem after all.
At least it has now had a good going over and everything else it might have been has now been looked carefully at and anything that could be serviced or cleaned has been.
Only thing that has 'issed me off is that it started off with a full tank and after I had ran it ticking over and then road testing it cost me £57.00 this morning to fill it back up!
Happy as larry again