Poor Starting - Petrol V6

[harryO]

I am 'back to the drawing board' with the occasional poor starting! Last thing I replaced was the ignition switch - clearly it was OK and the old one is listed on 'parts' if anyone wants to eliminate the switch from a similar problem. The car is only used a couple of times a week and 75% of the time, starts straight away. When it fails to start first time, I need to attempt to start it four or five times, with a pause in between.

After switching the DI packs with the spare, the first thing I replaced was the CPS. Then temp. sensor, MAF sensor (I have a spare) various relays and fuses. Then of course, the ignition switch.

Any ideas?

[Audax]

Is it turning the starter and not firing or not doing anything, can you define more what you mean by "poor starting"? Does it have new plugs of exactly the right NGK type?

[harryO]

Yes, the starter turns the engine as normal. It just does not fire up. Very much the same as if the CPS had failed. It has been much the same for as long as I have had the car (about 3 years) and the plugs have been changed twice. At first, the effort used to drain the battery, so I bought a new and better one.

[Steve440]

Have you tried giving it a squirt if easy start?

That way you will know if it is sparking if it starts or at least splutters.

Steve

[harryO]

No, I have not tried that. It's not that easy with such a complicated air inlet. Would be worth trying if it continuously failed to start.

[Audax]

Agree on that, it's a bit of a hard one to sort as you don't know if it's going to do it or not 

Can you hear the fuel pump on starting? Wonder if it's a dodgy relay or bit of wiring. You could try cleaning the electrical multiblock on the bulkhead in the engine bay with some contact cleaner. (I think the V6 petrol has one anyway).

[harryO]

No, I cannot hear the pump, but there is always some pressure in the system which would make the engine start, even if it is only for a few seconds. I tried swapping relays etc. and there are some large Maxi fuses in the engine bay which were very dirty. I cleaned them and once again thought the problem had been rectified, but no! The ignition switch was the last hope.

I am now thinking a faulty ECU or DICE, but even if I take it over to Southampton to the main dealer, I doubt whether they would be able to confirm it one way or another without changing the parts.

[Steve440]

I would disagree about the fuel pressure, what little pressure is there will disappear once the first injector opens.

You could just have a failed fuel pump, quite common and there are repair kits available.

Easy to see if the pump is working, just put a 12v supply to pump and you will hear it with the seat lifted and inspection cover removed.

You could also while in there put a meter across the wires to see if there is +12v with the ignition on, I think it only stays on for 5 seconds with the engine not running so probably best to have an assistant on the key.

Is there no vacuum hoses you could pull of to squirt some easy start down?

Steve

[stevetreacy]

No, I cannot hear the pump, but there is always some pressure in the system which would make the engine start, even if it is only for a few seconds. I tried swapping relays etc. and there are some large Maxi fuses in the engine bay which were very dirty. I cleaned them and once again thought the problem had been rectified, but no! The ignition switch was the last hope.

I am now thinking a faulty ECU or DICE, but even if I take it over to Southampton to the main dealer, I doubt whether they would be able to confirm it one way or another without changing the parts.

I can hear the fuel pump quite easily on my V6 petrol. I would start looking at the pump or maybe change the Pressure regulator. If you have WIS look at performing a Fuel Pump Capacity check.

Good luck

steve

[harryO]

OK. You have convinced me to look at the fuel pump, but I have always pulled the fuse (7?) whenever I wanted to do a compression test or take out the injectors etc. and then started the car to clear the fuel. It normally fires up for a few seconds.

It would be a lot easier if it just refused to start every time!

[saab9002]

Hi Harry0
If you live near Southampton, Hants. give Nigel at North Motors at Cheriton, near Winchester a ring he's a Saab specialist and knows what he's doing, the number is 01962 771331.
It's a bit hard to find first time, but worth it and alot cheaper than a main dealer.
regards Chris

[harryO]

Thanks Chris. I am very near Southampton, but have to cross the most expensive strip of water in the world - the Solent! One of the reasons I have not sought the dealer's help before. Last time I had an intermittent fault (9000SE), they first changed a part costing about £100 + labour, then when it made no difference, had it there for a few days and reported "suspect ECU". Have not bothered since.

I am checking the fuel pump and must have a very quite unit. However, it has kicked in every time I have turned the key, so far!

[Paul Dilley]

I have got the same problem but have not tried all the things you have tested. Two things you may try though

1 lock and unlock the car by remote   Had this problem on a 9000 and it can be the time out on the alarm system

2 Move the T handle on the Auto select back and forwards a couple of times. Could be the safety swithes are not quite making.

Please let me know if you find a solution as the problem has certainly stopped me using the car as a get away vehicle in cold weather.

[harryO]

Thanks. I will try the locking next time - not too sure if there is anything that can be done with the 'time out' on the alarm system - but pretty sure that if the auto switch does not make a good contact, the engine will not turn over.