It's beating me

[jonc3725]

Ok so I have a small problem which at the moment is beating me on my 3.6.

The car starts first time everytime when cold and when I take her out she drives like a dream but when I park her up (which tends to be on a slope around my house or garage) she is a pig to get started and infact she will turn over with nothing happening. I thought it could be the petrol level in the tank when it first happened then my fuel pump gave up the ghost so I thought it may have been that causing the problem. Yesterday took her out and parked her on the drive so I could service the wifes car in the garage and she was left on the drive overnight. This morning she was a pig to start.
I have a good spark and fuel is being delivered, swirl tank filter is clear and fuel filter was new last year but I'm not sure if the parking on a slope has anything to do with the problem or if its a red hearing.
Anybody with a bit of tech know how have any thoughts?

[Mr.Ian]

Are you sure fuel is there and the correct pressure?
Not sure on the 3.6 but the early V12s are known to suffer from 'hot start' problems. Nothing wrong with the pumps but the fuel can tend to evaporate in the lines near the engine when left hot after a run.
The overnight standing might be the 'non return valve' in the fuel line/pump letting the pressure drop and fuel to return to the tank if parked nose up.
I'd put a pressure guage in the fuel line somewhere on the engine to be sure.
Or try turning the ignition on and off a few times to get fuel flowing and pressure in the system before trying to start.

[masterb]

Have you tried checking out the small fuel tank below the battery, to see if it is full of gunk?
Maybe your nylon mesh filter is all caked up?

[jonc3725]

I've checked the swirl pot and it's clean. The mesh filter is spotless.

I will have a look at the fuel lines, didn't know there was a non return valve but it would make sense. I will get a pressure gauge on the line and see what happens. Something for me to look forward too next weekend .

Cheers Guys

[iain1980]

A couple more suspects to add to the list! - sorry!
Was the engine hot when you parked it on the drive? They are well known for flooding.
From memory(not sure) I think there are two fuel pressure valves, one in, one out, could the inlet be restricting or the outlet not keeping pressure?
Fuel tank breather? Temperature sender?

P.S. Lovin' the stripe! my first was a BRG V12 and I was soooo tempted to go for that look!

[jonc3725]

Cheers Iain,

Temp sender was my first thought. The engine had not warmed up too much last week because I took the car out the garage and drove around onto the drive. There is only one fuel presure valve I know of on the 3.6 which I replaced when I rebuilt the engine. The tank breather was new but I will blow it through to check. I tend to agree with you all that it's on the fuel side so I will spend some time on it this weekend. Just to add insult to injury read my post in general what a nightmare!!!!!

[jonc3725]

YYYYEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSSS

Problem solved. I have spent months trying to find the problem, checking all the following and finding small snags on the way:

1. Fuel system
2. Ignition system
3. Fuel injection system
4. ECU information systems.
5. Engine components.

After checking all this and replacing duff components (it's amazing what you find wrong and the engine will still run ). I still had the hot start problem. I read other forums for ideas and everyone was stating stuff I had checked (and double checked )

At the end of my tether I decided to contact David Marks who was brilliant.

The early 3.6's with the V12 fuel injection system suffer a lot from this problem and amazingly the first check is not atomising fuel, valve clearances, information senders to ECU or fuel problems. The issue is to do with timing

What happens is the timing chains stretch over time (yep we all knew this one) but what occurs is the cams fall out of timing with the pistons so much so that when under normal fuel conditions the car will not start.

I set TDC of No1 piston with a DTI and then tried putting my cam setting tool across the cam and it showed that the cams were at least 2 degrees out!!!!.

I slackened the top chain tensioner and reset the cams using the setting tool leaving No 1 piston at TDC. I then redid the timing and guess what the car now starts first time everytime .

We have seen on here resetting the tappets clearances had the same affect but this is probably because the cams are reset using the camsetting tool to TDc of No. 1 piston at the end of the set up. All I have to do now is send the ECU off to AJ6 Engineering and get the AC working. The car has now passed through it's first 200 miles with no other ill effects.

Thanks to David Marks for his help (can't recommend him enough) and I hope this information helps other 3.6 owners with the same problem.