P1800s starting issue
 

Hi trying to sort out a few minor issues. Ideal time as it is in the garage for repairs. The car struggles to start
Once it has started there is no problem unless left for a few days. Current starting procedure. Suck fuel through to carburetors. Turn key in short bursts for approximately 40 seconds. Car starts. When stood fuel either evaporates. Drains back to the tank. Or as I suspect both. Can I fit an electric pump in place of the mechanical one and would this solve the issue.
Regards Paul

You've got one or more of the following problems :

Worn fuel pump

Air leaks between the tank and pump

Clogged fuel filter

Incorrect float level in carbs

Incorrect mixture (possibly aided and abetted by weak/missing thermostat)

Choke mech out of adjustment/not working

Incorrect contact breaker gap/dwell angle

Incorrect dynamic ignition timing

Incorrect plug gap

Defective dizzy cap and/or rotor arm

Burned out ballast resistor (if fitted)

Lack of ATF in carb dashpots

Split diaphragm(s) in carbs (if Stromberg)

Air leaks on inlet manifold

Petrol leaks on one or both carbs

Carbs out of balance.



This is not an exhaustive list, just the most likely culprits. Chech the ignition related things first, then for air leaks between tank and pump.

After that check the other stuff if you haven't found the problem, starting with a weak/lazy/worn fuel pump. Also worth checking the fuel filler cap (if it's the one with a breather - "Vented" - variety) isn't creating a vacuum in the tank.

'Suck fuel through to carburetors'. What does that mean - detach the hose and put your lips on it and suck? If so, your fuel pump needs repair or replacement. There are check valves in the pump that should prevent drainback when shut down. Also, normally on shutdown there would be fuel left in the float bowls that would quick facilitate restart. Are your float bowls empty after the car has been sitting for 'a few days'? If so, you need to find out where the fuel is going because the leak may be compounding your starting problem.

Thanks for saving me typing that out - i pointed the short version out in my post above with a whole host of other possible faults and suggestions where to start.

However, casting my mind back to when i had cars with dodgy fuel gauges, weak batteries and i ran out of petrol all too often, i know if the fuel pump is ok it's pretty hard to suck the fuel through the pump, through the pipe and from the tank.

Some of the other things need checking (ignition related) before he even gets to checking the pump and/or air leaks on the inlet side of the pump.

Starting issues.
 

The carburetors have been totally rebuilt and tested by Burlen costing just over £500.00.
I seem to remember upgraded plastic floats.
The ignition is electronic 123. Hi power coil all new leads plugs. Gaps checked. Paid for a professional set up with valve clearance check. New fuel filter fitted in engine bay
After a couple of days fuel has run back and the fuel filter is almost empty. Just going through my hundreds of receipts to see if I have ever replaced the fuel pump.
Regards Paul

Just a thought: years ago I had similar with my then Volvo 164, and went through most of the points Laird pointed out, to no effect. I had a spare fuel tank so swapped that in desperation - and all was fine.
I got inside the original tank and found the delivery pipe within the tank was just about rusted solid, almost blocking the fuel supply.
As an aside, I had similar on my P1800 two years ago and it turned out to be a blocked fuel filter so swapped that. However I was told some but not all 1800s had another filter in the tank - called something like a Saran filter. Worth a look just in case.

P

My cars have suffered from this problem, which I have solved by fitting a cheap electric pump in the fuel line, which I switch on to bring the fuel up to the carbs, then switch off, to run on the original pump. I can't see that there is a problem with low pressure on the mechanical pump as the car will run at 80 mph for an hour or so with no problems.( On French autoroutes).

Just checked new fuel pump fitted. Bought from Amazon cars. Not the glass bowl type.

The problem appears to be fuel running back to the tank.
I would rather fit an electric fuel pump and remove the old one if this is an option. What pump would be suitable to deliver the right amount of fuel ? Regards Paul

Couple of questions then - how long ago, has it been stood since and have you checked the fuel line from tank to pump?

It doesn't take much of an air leak in that pipe/line to cause exactly the problem you've got and it will probably get worse to the point of leaving you stranded! I speak from experience with a 144 DL auto some 35 years ago, it began to be a pain to start when cold, then also when hot, power was down and the economy wasn't what it should be.

Then i found the fuel hose perished, can't quite remember where but it was between the tank and the pump. Renewed the section of hose, turned the engine over in a few shorts bursts (about 3-4, can't quite remember but didn't take much) and it once more fired up.

Fuel economy, instant starting, power and smoothness all restored.

Also worth checking your fuel delivery, if it's insufficient you can increase it by selectively removing the gaskets between the pump and the block. Don't discount a part simply because it's new either, on another occasion with that 144, the points burned out, leaving me stranded. I hitched into the nearest town, bought new points and condenser and fitted them. Started up and was fine until i got about 1.5 miles further down the road. All looked good when i checked the points as my first thought was i hadn't done the screw up tightly enough and they'd closed up.
Second thought, on a hunch was to refit the original condenser - fired up straight away!

Took the new condenser back to the shop and it was replaced so fitted the second new one in the space of an hour. All good after that and eventually i upgraded to a Sparkrite SX2000 contact-triggered electronic ignition and no more problems.