Clubman 1.3 fuel starvation

[JMW]

Hi all,

I'm getting fuel starvation on my 1.3 Clubman, which I use to commute to work. It usually happens at the first traffic lights after the long part of the run along the M3 motorway (top of the Blackwater valley road on the way to work, and Hospital Bridge road on the way back to Twickenham.

When it fails, it seems to run away from the lights up to 3rd or 4th gear, then cut (though if I have a longer stop at the lights like yesterday, it barely crosses the junction!). On most occasions it will start again if I wait between 15 and 30 minutes, and don't kill the battery.

It first happened about 6 weeks ago on a warm day, and seems to be more prevalent in warm weather. On lifting the bonnet, the fuel filter between the pump and the carb is full of air. Thought it was delivery from the tank, but pulled the inlet pipe off the pump, attached a tube and sucked (and blew), and it seems to be flowing freely.

I changed the pump (found one on eBay for £4:99 + postage) last week, thought that fixed it, but no. Yesterday it stopped both ways and again on the way to work this morning. Last night, pulled the pipe of the pump outlet, tried blowing in it, and was completely blocked. Suspect carb float valve, but that would not explain nothing but fumes in the pipe up from the pump.

Later, took the filter off the carb to get at the other end of the pipe, pulled it off the carb end (now attached at the pump end, and sucked - got a dribble of fuel up from the pump, and clearly not the pipe or fuel filter blocking.

This morning when it stopped, I pulled off the (float chamber) breather pipe that runs from the carb to the crankcase - sucked hard, and seemed to get some fuel up from the pump, so tried starting again and off she went.

I looked it up the carb in Haynes manual last night, and it doesn't seem to match. My carb does not seem to have the stepping motor, fuel cut off valve, or ECU (in fact there are no wires to it at all) - was it standard to fit a basic carb on the bottom end model? Its J reg, bought early 1992, under 75,000 miles of which 11,000 was my mother before she died in 1997, then it remained in the garage until I picked it up in 2004, and started commuting in it.

Any suggestions welcome. (PS ignition perfect - I replaced the distibuter 3 months ago, fitted new plugs, and checked the timing with a strobe, and it is the strongest it has ever been; this problem is definitely fuel starvation). I'm thinking of examining the fuel pipe from the tank next, but I don't have a pit so thats more difficult.

[E_T_V]

Disconnect the pipe from the fuel pump to the carb and place the open end of pipe into a jar. Get someone to turn the engine over. You should get a good strong regular spurt of fuel from the pump. If not then the pump or fuel line or tank is faulty. To prove the pump is ok disconnect the intake side and attach some pipe to the inlet. Dangle this pipe in a fuel can with some fuel in it to prove that it can suck up fuel from the can when cranked. If it doesn't then the pump is faulty. If it does then you are looking at the fuel line or tank as potential problems.

Try blowing back through the fuel line to the tank. You should be able to blow through it and eventually you'll hear bubbles in the fuel tank if all is ok.

If the pipe is blocked then you'll have to get under the car and find out where (it isn't a common problem).

Lastly if the pump and the fuel lines prove ok then it is possible to have a faulty fuel pickup in the tank which is leaking air into the system. If the problem is worse with a lower fuel level, but ok with a full tank then I'd suspect this as the cause, however again it isn't a common fault.

[JMW]

Thanks for the advice. I'll try pulling the pipe from the carb and cranking, next time, as I haven't done that yet, but as it is impossible to create the problem on demand, it is unlikely I will have anyone with me to hold it over a jar - can probably duct some tube from it away from the car to reduce risk of fire. The problem has occurred with a 3/4 full tank (which at the time discouraged me from messing about at the tank end - even if I had a pump, I could not store about 7 gallons of petrol).
The pump is brand new, and the symptoms are the same as before I changed it, so I don't suspect the pump any more.
I have already attached an extension to the tube from the tank to the pump and can blow back all the way to the tank, or suck until the petrol comes up (I have done this on 3 occasions now without discovering any blockage). If there is an air leakage into the pipe between the fuel tank and the pump (that was suggested on another thread on this forum dating from several years ago), I'm surprised it hasn't leaked petrol.

[G Force]

. Last night, pulled the pipe of the pump outlet, tried blowing in it, and was completely blocked. Suspect carb float valve, but that would not explain nothing but fumes in the pipe up from the pump.

If you did this when the car had broken down then I would be suspicious that all is not right in the carburettor.

With the float chamber empty of fuel you should be able to blow into the carb inlet pipe reasonably easily, because you could not then I would suspect a blockage in the small gauze filter in the float needle and seat assembly or more likely the float itself physically sticking for some reason.

I hear what your saying about the air in the pipe from the pump but you can sometimes get some air in the pipe when the fuel pump is on its idle stroke when an after market filter is installed.

The float chamber vent pipe you mention should not go to the crankcase it is just connected to a metal pipe leading down to the lower front of the engine block and is open to atmosphere. This pipe should be clear and unrestricted but if it has a lot of petrol in it, the carb could be flooding.

Don’t worry your carb is not like the one in Haynes as the Maestro 1.3 all had manual chokes after around 1989.

[JMW]

[QUOTE=E_T_V]Disconnect the pipe from the fuel pump to the carb and place the open end of pipe into a jar. Get someone to turn the engine over. You should get a good strong regular spurt of fuel from the pump. If not then the pump or fuel line or tank is faulty.

About 20 minutes after my last post, I was driving home, and the engine cut again just after joining the M3 at junction 4. Quickly detached the inlet pipe to the carburettor, attached an extension length of plastic pipe, and turned the engine over with the starter. It caught and burst into life for about 5 seconds on the remaining fuel in the carb. However, no more came up from the pump. I then undid the nut that holds the metal pipe on the end of the engine, so that I could remove the inlet pipe to the pump. That took about another 5 minutes, and when I got it off, and attached an extension to it, the petrol flowed immediately up my transparent pipe when I sucked, and was flowing freely from (and to) the tank. Not sure I proved anything. The pump could have sucked the air up in the 5 seconds it ran, bringing the petrol up to the pump but no further. Also, I'm not sure how this fits in with the observation I made earlier that I could not blow into the carburettor, when it clearly had insufficient fuel in it to run the engine, i.e the float chamber must have been empty. Connected everything up again, it started immediately, and I carried on homeward.

25 minutes and 20 miles later, it stopped again on the A316, fortunately just before the Winning Post pub, so I was able to coast off, and fix it in the pub car park (the kerbs on that stretch of the A316 have been doubled in height to protect cyclists, so a breakdown blocks one lane of the carriageway!). In a bit of a hurry to get home, I just pulled the carb end of the pipe from the pump off and sucked, to see if I could drag some petrol up. There was a bit of resistance at first, but then I got a little petrol and a fair amount of gas (air or evaporated petrol) coming up the pipe into the transparent inline filter. Gave up after about 2 minutes, due to horrible taste in mouth, and not getting any more petrol up. Pushed the pipe back on the carburettor, started up, and got home (about 3 miles) with no further problems.

Tomorrow, I have a day off, and am thinking of putting the back end of the car on wheel ramps, and having a look underneath, possibly disconnect the pipe at the tank end, block it up, and try a suction test to see if it is leaking anywhere (if I can find a way of producing enough suction). Fuel tank is now down to about 1.5 gallons, so might be able to pump out the remainder, and take the fitting off the tank for inspection. I was not very comfortable about the Haynes description of how to remove the fitting on the tank, it sounds as if it might be quite difficult. Any advice?

Thanks to G Force for the reply about the carburettor. Relieved to hear that a manual choke is not unusual. Where can I find a manual for it? Haynes reckon that removing the (ECU fitted) carb is a 4 spanner job. Presumably the manual choke carb is a bit simpler. Is it fairly easy to get at the float chamber? I'm wondering if there is crud in the bottom of the chamber preventing the float from dropping.

My only problem tomorrow is that the car is sitting on the drive, perfectly servicable, so it may not yield any clues.

[Russ]

I had a simmilar problem with my efi,it turned out to be the strainer in the tank blocked. Am I right in thinking the 1.3's pick up is on the sender unit?
If so remove that and clean the gauze .

Cheers

Russ

[Russ]

Bye the way I had a hell of a job draining my tank as the pick up was so blocked I couldnt use a pump or syphon on it ,had to remove the filler hose and syphon from there.

[PhilD]

It sounds like you've exhausted all the obvious possibilities, so I'd be inclined to investigate the condition of the rubber parts of the fuel feed pipe. I've never heard of this happening, but what if one of the rubber pipes has deteriorated and collapsed or has a flap of rubber intermittently blocking the flow? Pressurising the pipe by blowing down it could then well move the blockage if this were the problem.
I think you need to remove the carburettor from the inlet manifold if you want to inspect the float chamber. This would require unbolting the four nuts and lifting the carburettor off. This is quite a fiddly job because there is not much space to get a spanner in on two of the bolts, but I have managed OK with a thin 1/2" combination spanner. You may not neede to disconnect the throttle and choke cables , but you would run the risk of losing bits in the engine bay if you chose not to do this and worked on top of the engine.

[tandeera]

Hi all, The chap who own's the one man garage down the dtreet from me told me about a simular problem. A man bought a S/H Vauxhall, the road test was ok,but the guy selling it said the reason for selling was that it kept stopping and he'd been to several garage's who had pulled the fuel system apart but could'nt find anything wrong. He took a chance and bought the car, it did run ok for a while then stopped for no apparent reason.
He was quite near a one man opperation who had been in the trade for 50+ yrs. His advice without looking was buy a new fuel filler cap, guess what Problem solved.

tandeera ex Maestro owner, who has a spare cly/head and carb for a 1.3