340 1.4 mechanical fuel pump?
 

Hello guys,

Today i tried to start the car and it refused to start.It cranks normally but it will not start.I decided to check the fuel pump(it's mechanical fuel pump).

I took off the "exit" hose from the fuel pump which goes towards carb and i got nothing,no fuel from the hose.

I removed fuel pump from the engine,attached feed fuel line to it,moved the spring up & down and i got fuel.

When i attached her back to engine....no fuel from the pump.

The pump is driven by the camsaft and i thought cam is not moving.Checked that and cam is ok,installed fuel pump to the engine,cranked the engine and again nothing.

Engine cranks normally but there is no fuel from the fuel pump.

When fuel pump is out from the engine and when i move the spring up & down i have vacuum,but when i attach it to engine i have nothing!

I could say that fuel pump is ok when i test it out from the engine.

I don't know what to do.
Misha.

That does sound strange. Could you get another pump to try? I bet there is something wrong with it...maybe you're able to apply more 'lift' when you pump it by hand?

cheers

James

I don't know,i will try to find replacement pump tomorrow.

Car was driven 3 days ago without any issue.It was parked and 3 days after it won't start.

Im really confused with this.

Has it been run dry of fuel...and is it often left for 3 days? If the lines are a bit porous, the pump can fail to draw fuel through when the engine is turning on the starter motor, but it will work fine with the engine running. If it has lost a little more fuel to vaporisation than normal, that could be a problem - try re-filling the carb directly?

Of course if the pump diaphragm has failed, it's pretty binary. Maybe it tore when you first cranked it today?

cheers

James

fuel pump
 

you can get a lot more movement out of the car it could be a streghted diaphrame in the pump,lucky if this is the case because if they leak you can end up with a destroyed engine due to petrol in the oil system ,good luck.

Your car may have a filter on the end of the fuel pick up pipe in the bottom of the tank which can get blocked , later years don't have this however . might be worth taking the tank sender out the top and looking .
whilst there, the two short different sized rubber pipes connecting the plastic fuel hoses to the tank sender are likely to be rotten by now allowing air in !

Problem solved guys.

It seems like the pump developed a little play in the "pipe" which goes on cam.

When i tried the pump when it was removed from the engine,it worked ok.

So,i just tightened it more towards it's housing on the engine,cranked the engine and it spilled fuel,then i reconnected the hose which is going to carb,cranked it few more times and it fired up.

Checked for oil leak,everything is ok.Added 0.5l of oil(which leaked through cam opening when i was removing the pump for a few times) and i drove it about an hour.

First few km's was like it's misfiring,but after that everything is back to normal.I guess it was because of trapped air in the fuel system.

I'll order the new pump,just in case that this one lets me down again.

I've had 2 fuel pumps fail on a B14, both broke the lever off the pump - no idea why. The first just refused to start at home one morning without any prior symptoms. The second, again without any warning, wouldn't start in a shopping centre car park. Luckily though, this was when shops like Halfords and Les Smith were still in shopping centres. A quick trip to Les Smith got me some fuel pipe, 4 jubilee clips, some 2 core cable, and an electric fuel pump (I'm told Morris Minor but I couldn't be sure), McGyver'd it all together (fuel pump wedged into the spare wheel strap, + to the key side of the coil, - to the battery, pipes all over) and it ran like that 'till I sold it over a year later.