I have a 33-34 year old Toyota Corolla (KE70), love the car due to the rear wheel drive & excellent design, though it looks like a rolling wreck nowadays. 

This car has never given any significant trouble in the 10-12years I've owned it. Well, a few weeks ago the aftermarket electric fuel pump began to cut out occasionally, so the mechanic suggested going back to the original mechanical type pump. It works great, but the problem was he allowed the fuel level to get very close to empty and the new pump apparently sucked an enormous amount of filth from the bottom of the 34 year old tank, befouling carburetor, plugs, etc. The car simply wouldn't run, or would run incredibly roughly (like most old pushrod Toyotas it had been sewing machine smooth previously) 

After extensive carb cleaning, new spark plugs, etc., the car is again drivable but with a terrible "flat spot" in the carb on acceleration, and is also noisy and somewhat rough-running. The idle speed, previously fine at a very low speed, has had to be set very high. 

I present this story as the sad tale of the decline of probably the best car I've ever owned (well best non-American car anyway), and as a cautionary tale: never let the fuel level go below 1/4 tank in an old car! 

CQ ... I have really missed  you. Why so quite for the last year .....

Clean the crap out of the system. Replace tank if cleaning not an option. Clean all the lines. Replace carb. With a NEW one, not a wrecker part.

Old cars need more maintenance. Why - for the last 30 odd years people adopted the 'If it ain't broke don't fix it' philosophy.

You wanted - or needed - cheap. This is the price you pay

Well no, canthai, I've always maintained the car correctly - timely oil changes, etc. I doubt a new carburetor would be available for this 34 year old car. Also the mechanic mentioned he was loath to remove the gas tank for cleaning as he believed it might break or spring a leak. 

 

JAS21, I've been a bit busy with work & had sort of lost interest in posting. I suppose I'd come to accept my travails as unsolvable. 

 

3 hours ago, ClareQuilty said:

Well no, canthai, I've always maintained the car correctly - timely oil changes, etc. I doubt a new carburetor would be available for this 34 year old car. Also the mechanic mentioned he was loath to remove the gas tank for cleaning as he believed it might break or spring a leak.

I did not mean you - unless you bought it new.

Its many owners before you.

New carbs are available. as are new fuel tanks.

Your mechanics need to repair it, not give excuses why it can not be done.

Two things can not be repaired - a broken heart and the crack of dawn

I assume you did not have an inline fuel filter..
 It should have one..

Forget the tank thing, just fit a cheap fuel filter before and after the pump..

 

I doubt there is a real problem with the carb. I have no idea what design carb you have so can't advise, but if it has an accelerator pump  your guy should have a look at it's diaphragm.

 

This thing squirts a bit of fuel in when you touch the go pedal to stop flat spots..

9 minutes ago, transam said:

Forget the tank thing

His mechanic said he was afraid to remove it as it might break or start to leak. This tells me that it is a POS, probably rusted almost thru.

2 minutes ago, canthai55 said:

His mechanic said he was afraid to remove it as it might break or start to leak. This tells me that it is a POS, probably rusted almost thru.

That's why I said forget the tank, it may well be a rust bucket and fall apart..

54 minutes ago, transam said:

That's why I said forget the tank, it may well be a rust bucket and fall apart..

So do not replace it, have it fail ... meanwhile filling fuel filters with crud.

Must be the B-Quik solution

Just now, canthai55 said:

So do not replace it, have it fail ... meanwhile filling fuel filters with crud.

Must be the B-Quik solution

Don't be silly...Cheap fuel filters are clear plastic, you just keep an eye on them and keep the tank at least a quarter full at all times.... 

The car did have a fuel filter, of course. It's been replaced with a newer, bigger one now. 

 

I'll ask him about the diaphragm.