Lack of petrol?

Thomas-P6

Thomas-P6

Member
Hi,
my 3500 Auto let me down completely yesterday whilst being on a long weekend trip to the coast. The car ran fine for more than 600 km on the way up, but then decided to quit the morning we wanted to drive back home. It started up nicely, but quickly began to cough and finally quit running completely about a half a mile later. In my opinion, the float chambers in the SU's had emptied and did not get re-filled. I had to call a tow-away service from the Automotive Club and they brought me to a local garage where we tried to solve the problem, but with no success.

General condition of the car is very good, she never gave me an engine problem for the last 10.000 km. The carbs were re-built about 2 years ago.

Here is what we did:
- checked petrol filter, looked clean from the outside
- fuel was fresh from a couple days before
- removed the pipe going from the filter to the carbs and blew through them - no blockage
- cranked the engine, and the mechanical fuel pump produced a nice fountain coming out of the top of the fuel filter
- took one carb off and opened the float chamber - no muck inside, the needle valve was moving up and down easily
- since I happened to have an electrical fuel pump as a back up unit on board (purchased from JRW), we decided to put in it (it also produced a nice fountain)
- blew air through the pipe going back to the tank - no blockage (when sucking, petrol would come up easily)
- finally, we even offered fuel to the pump from a separate cannister

Nothing helped. Every attempt to start the engine failed. The engine would sometimes fire up, make a few irregular puffs, and then stall again.
Ignititon system is in good order. I ckecked the spark plugs and the were dry as they should be.

At the moment I am a bit lost. Whilst waiting for the car to be delivered home in the next few days, you guys may have some clues.

Thanks

Thomas
 
might be the coil? Mine gave up completely and it kills it like you describe - it breaks down internally but can 'cool off' and work intermittently.

Or a big old leak in some vacuum pipe somewhere (had that as well).

To fully rule out the carbs then you could try starting it with no filters or things on so you can see into the mouth of the carb, where you should be able to see fuel going in from the jet.
 
Same could be said of the condensor .If the engine has fuel , compression and a spark occuring at the right time , it should start and run
 
Thanks for your suggestions but I thought the ignition could be ruled out.
The spark plugs are absolutely dry which they obviously would not be when there is not sufficient sparking.

Thomas
 
Thomas-P6 wrote,...
cranked the engine, and the mechanical fuel pump produced a nice fountain coming out of the top of the fuel filter
Click to expand...

Hi Thomas,

Given the above, I think you can safely rule out a fuel supply shortage as being the reason. If your engine is still running on points, then should either the capacitor or the nylon piece into which the dwell adjuster screws, fail, then the symptoms will be as you describe.

Have you taken the coil lead off at the distributor end and cranked the engine over so as to establish the existance or not of a coil spark?

Ron.
 
When you have the car back, you can remove the air filter housing and the elbows. Then ask someone to start the engine and at the same time spray some brake cleaner directly into the carbs (with open butterfly valve). If the engine runs directly after spraying in the brake cleaner, then you have a fuel problem, otherwise it will be the ignition.
regards
Peter
 
roverp5Bcoupe wrote,...
Then ask someone to start the engine and at the same time spray some brake cleaner directly into the carbs
Click to expand...

Hi Peter,

Brake cleaner is as I understand it, a seriously nasty chemical that can cause liver damage if inhaled. Personally, I wouldn't be advocating doing that at all.

Ron.
 
A butane blowtorch would be better. Same as running on lpg then.

*edit- usual caveat applies, be careful etc.

*edit2- have heard of this being done on 4 cylinder Land-Rover engines, but not the v8, so may not work! If you have a big enough gas feed I can't see why not though.
 
Thomas-P6 said:
The engine would sometimes fire up, make a few irregular puffs, and then stall again.
Click to expand...

DaveHerns said:
Same could be said of the condensor .If the engine has fuel , compression and a spark occuring at the right time , it should start and run
Click to expand...

Hi Thomas, as Dave has said it could be the condenser? I had symptoms like you describe above ^ after replacing a condenser with a brand new one. It only lasted a few miles and packed up. Luckily I found an old one in amongst a draw full of my Dads 'electrical' spares. The car then ran fine after replacing the new for old.

Will
 
Thanks for all the messages.

I'll check the ignition system once the car is back. She still runs on contacts and condenser, and I had aimed at keeping it that orginal way. Now, I will convert to Pertronix electronic ignition to get rid of that common problem of poor quality replacement parts for good. You will hear about my progress when it happens.

Thomas
 
The car is now back to my garage and I started to sort the problem out. Since the mechnical fuel pump is removed anyway, I grabbed into the opening and checked the timing chain.

SHOCKING! It is so loose that the side of the chain can be moved in and out by about an inch! Surprising the engine was still running smoothly with no apparent chain noise. I have been reading here about that issue and the urgent need to replace it. The car still has the nylon sprocket, but the teeth I could see are all present and not broken off. The car has done about 105.000 km

Anybody can recommend a source for decent replacement parts? Which other parts (especially gaskets) need replacing when doing this job?

Thanks for your input.

Thomas
 
Hi Thomas,

My understanding is that the Morse type timing chain, which is not a roller chain, only last about 30,000 Miles (50,000km) before they are significantly stretched. They won't break, but the greater the stretch the more retarded the camshaft timing becomes. This is directly attributable to a loss of low down performance, however on the upside it also improves top end performance.

The original timing set from my 3.5 engine saw just over 203,000 Miles (327,000km) of service, and when removed there were only two nylon teeth left. :shock: All the others were worn away!!

If you decide to replace the timing set, a full steel set with roller timing chain is the way to go. There are aftermarket as well as OEM Rover sets in steel. Either are perfectly acceptable and will last infinitely longer.
You'll need to replace the the timing cover gasket and the water pump gasket should you choose to remove the latter from the timing cover.

Ron.
 
Thomas-P6 said:
Anybody can recommend a source for decent replacement parts?

Thomas
Click to expand...

Hi Thomas,

IMHO the OEM timing set was always a weakness...this is the billet set I went for on Occie:



From RPI Engineering via ebay a good few years ago...IIRC about £60.

Can't see an ebay listing at the moment, but give them a call...sure they must have some...or similar.

http://www.v8engines.com/

Real Steel also a good source.

Stan
 
Hi,
obtained a new billet time chain set from RPI and installed it. Also fitted a Pertronix I electronic ignition.

The engine started up after a few trys, but is not running well at all. I suspect a problem with the valve timing now, although I am pretty sure to have installed the sprockets and the chain properly with the timing marks in line.

Nevertheless, I want to double check the valve timing and need to confirm which valve is which. From information found in the workshop manual, I gather that the first valve in the left bank (the one closest to the radiator) is the exhaust valve, then comes the inlet valve. Correct? Is this sequence repetitive and uniform for all cylinders?

Thanks for your help.


Thomas
 
It goes exh, inl, exh, inl, to the middle then inl, exh, inl, exh. i.e. the outer two on each bank are exhaust valves.

Richard
 
@Richard: thanks for the info.

I tried to actually measure the opening and closing angles of both valves, but I am getting inconsistent readings.
While turning the crank, I was taking readings when the push rods locked or freed up again, indicating the closing or opening of the valves.
My suspicion is that the tappets have an effect on the readings by offering more or less resistance. Am I right in assuming this?

What is the experts advise on checking cam timing properly, before I go out and take the entire timing chain assembly apart again?

Thanks
Thomas
 
Hi Thomas,

What leads you to believe that there is something not quite right with the valve timing? Have you changed the camshaft, lifters, pushrods, rocker assemblies or is it only the timing set? If you only changed the timing set and the engine isn't running right, then the problem is somewhere else, assuming that you did install the set correctly.

Why do you not suspect the new electronic ignition?

Ron.
 
Ron,
interesting point you're making! You are right, all I changed was the timing chain set - and the Pertonix.

But:
- ignition seems to have been my initial problem (probably just a defective capacitor where I thought "Lack of Petrol")
- now, the engine is reving up well, there is no sign of poor sparking or so
- I suspect the cam timing because the engine is running a bit shaky/rough, such as there would an internal resistance working against the combustion. In addition, it developped an ever louder getting mechanical noise, similar to a defective tappet. It never did that before, but ran smoothly all the time.

I took off the rocker shaft on the left bank and used a feeler gauge set to the top of the pushrod to see when the valves start lifting and finish closing. The readings now indicate about 15° difference to the target values (inlet should open at 30° BTDC, but I read 15° BTDC, meaning I'm too early). I suppose I will have to take the timing cover off again and check the alignment of the sprockets. Grrrr!!!

Thomas
 
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