V8 that keeps cutting out

#1
Help Me Please somebody. Ive got a 1973 v8 auto which keeps cutting out every 2-3 miles. It all started last year when she ran out of fuel.I put some fuel in but she would not start. In the end we had to take off the fuel pump and manually pump the fuel through to the top of the engine, We got her running and i thought the problem was solved. Then the next day i went out for a drive, she started up from cold ok and you can drive around untill she gets warm. Then she starts spitting and farting untill she stalls. Once this happens she will not start again untill you use easy start then she runs for a couple of miles and the process starts again. I think its muck in the fuel lines but i dont know where to start. Any advice would be much appreciated.
Cheers. Simon.
 
#2
I had a similar problem with my first V8, that was fitted with the original mechanical fuel pump. It was fine when cold, but when it got warmed up, it would start coughing and spluttering, and then quit. normally at the worst moment as well! My problems were traced to a duff mechanical fuel pump.

From what you have described, I would definately check the fuel lines. Compressed air is handy for this, as you can remove them from each end, and blow them clear. But try and drain the petrol out of them first though.

Good Luck!
 
#3
Simon,
or dirt / rust particles could have got through the fuel lines in to the carb. float chambers and blocking the needle valves (especially if you do not have an in-line filter fitted.
Regards, John.
 
#4
Ok, Thanks chaps i do have an airline so i will try that and check the float chambers. I will report back shortly.
Many Thanks.
 
#5
Someone ( Paul Atkinson maybe ) told me there was a plastic part of the fuel pick up that could come detached and block the fuel pick up
MIne would run on the reserve supply and cut out on the main supply . Blowing back down the fuel lines into the tank seemed to cure it
Never got round to taking out the tank to see what it was
 
#6
Checked carbs and float chambers and all seems fine. I will check fuel pump and lines on sunday. Car went to cut out again today but i managed to keep it running by pulling out the choke, the car recovered and then ran as normal for a few minutes untill it started all over again. This is very strange.
 

keanej

New Member
#7
Sounds like the pump needs reconditioning, kits are cheap

Cured a intermittent none starting problem on mine, started OK when cold but switch off when warm and it wouldn't start for ages - I put it down to faulty none return valves in the pump, it has been OK since I repaired it
 
#8
I had a very similar problem on my BGT V8. Spent ages on the fuel system only to find the following by chance. The main power and solenoid wires from the starter run very close to the exhaust down pipe and the heat apparently hardens both the plastic issulation and the wires themselves to the point where they start to break. Quite why this causes the engine to die after a few miles I don't know but replacing the wires (there's a connector about 4 inches from the solenoid) and fitting heat wrap cured my B. I have since been told that Range Rovers suffered similar problems, so maybe P6Bs will as well.
 
#11
Yes it does, the two wires I referred to are the solenoid wire from the ignition switch and the master live feed to the fuse box which will of course activate the ignition circuit. What I could not figure out was why it would start and run until it got hot if this wire was the problem, however it clearly was my V8's issue as replacing the wires fixed it.
 
#12
Thanks for all your advice. I am purchasing an electric fuel pump at the weekend from my local shop. But i will go and check the wires from the starter now. I have also lost reverse gear now as well today, so a new autobox is looming i fear. I cant remember my dad having all this trouble when he had his p6. Reliving your childhood is expensive stuff.
 
#13
Hi there,

I have a 1973 P6 3500 with similar problems which are driving me nuts because I am no great mechanic myself and have to take the car to the garage. They specialise in classic cars and seem to know a fair bit but as the fault is intermittent it is difficult to track down.

My car would run roughly after 10 miles or so (today it also felt as if it had difficulties deciding which gear was right) and then cut out. It would sometimes not restart for an hour or more (tow truck to garage: garage man turns ignition key and car starts and runs perfectly grrrrr).

This has happened twice in town traffic, and twice on low fuel going up a hill.

The distributor has been checked and the spark is fine. The fuel pump has been refurbished but there were no replacement valves in the kit.

Once when this fault occured in town traffic the temperature had shot up and today (although the temperature was shown to be in the green) I thought the radiator was nearly boiling. I opened it carefully and there was a lot of pressure and a fair bit of fluid came out.

My questions are:

Is this just one fault or is there more than one problem?

Do you think an electric fuel pump is likely to help?

Is the car just overheating? And if so what can I do to prevent that from happening?

Thanks,

michael
 
#14
Hi Michael, I had similar problems and last week replaced my fuel pump for an electric one. The car seems to run fine and for the first time in a year or more i can drive it without the worry of it breaking down. I like yourself purchased a service kit for the mechanical pump and didnt receive the correct jets.The arm on the pump and the spring can also wear. The electric pump will cost you about £65 plus 2 unions some petrol pipe,a blanking plate and some clips and wiring so you wont get much change out of £80.But i think its worth a try. Cant help you on the overheating problem allthough i had a hole in my bonnet where the radiator cap once fired through it so be carefull when taking the cap with a hot engine. Let me know how you get on. They are super motors to drive when they run right. Good luck.
Simon.
 
#16
Its a facet electric fuel pump and i purchased it from my local motor spares shop in elm park in essex. You can buy them off ebay from time to time for around £65.00. If you live local i can give you their number but you shouldnt have a problem finding one.Good luck
Simon.
 
#17
keanej said:
Sounds like the pump needs reconditioning, kits are cheap

Cured a intermittent none starting problem on mine, started OK when cold but switch off when warm and it wouldn't start for ages - I put it down to faulty none return valves in the pump, it has been OK since I repaired it
Hi.

The pump has already been refurbished.

The rough running/overheating has not been cured and with an overheating problem I cannot drive the car until to test whether what might have been the fuel problem/cutting out is still around.

THX
 

JC.

New Member
#18
Have you tried checking the stat opens in a pan of boiling water on the stove?
Is the Rad in good condition?
Are the carbs set up right? What colour are the plugs imediately after the car cuts out? That will tell you how the car is fueling.
Air lock?
Condensor breaking down?
Shagged out coil?

Start with the cheap stuff and swap them for new parts untill the problem goes away.
 
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