Occassional fuel starvation

[Mikep]

Hi All,

I'm a little perplexed by my current problem. Last week I experienced what I think is fuel starvation for the first time since I cured my vaporisation issues and relocated the fuel pump to the rear (Facet Posi-flow).
It first happened last week when I kicked down to join the motorway and by the time I got to the end of the slip road I started loosing power and the car started surging causing me to crawl along at 40mph. After about a mile it stopped so I finished my journey with minimal acceleration. The same happened a couple of days ago just after I kicked down and accelerated heavily. My initial suspect was a restricted fuel filter due to the sediment that seems to be in my tank.
When I relocated the pump I fitted a fuel filter before the pump. The pump has its own filter and I fitted another under the bonnet (you can see that I'm paranoid about any dirt getting to the carbs ). I replaced the rear one today as it was full of crud. Took the car out for a spin and even though the pump occasionally clattered (its normally quiet but has been doing this of late again leading me to suspect its being starved of fuel) all seemed fine until after six miles it started to falter. I pulled over for a minute and continued without an issue until a few hundred yards it did it again :x
Just out of interest the filter at the front never has anything more than dribble at the bottom, should I expect the fuel to submerge at least some of the filter? The pump I have fitted has always performed ok but could the three filters be causing to much of a restriction? It had seemed ok until last week. and lastly, this pump is a brand new one fitted in the new year due to the old one packing up; its exactly the same as the old one.

Sorry for the long winded post but hopefully this gives a good idea of whats going on.

Mike

 

[Demetris]

Don't be surprised if the new fuel pump is playing up.
A few years ago i was unlucky enough to be introduced into a "bad batch" of new, quality, electronic fuel pumps for the Austin 1300. They were identical to the one that gave sterling service for many years, but the replacements were stopping running for a few seconds when they felt like, causing the symptoms that you describe.
On flow measurements they performed faultelessly, it was just in normal service conditions that they were playing up. Not believing that new pumps could cause problems, i spent a couple of desperate months trying in vain to fix everything else, that obviously wasn't the problem. I only found out when the problem became worse enough to leave me stranded at the hard shoulder, and the carb was found dry.
This was the culprit.

 

[Mikep]

That thought had occurred to me too Demetris. Its a long shot but Im going to fillup the tank today to see if that will make any difference. This doesn't happen all the time, it may be a coincidence but when it does the fuel is low. Maybe the sediment in the tank is affecting the flow :?

 

[rockdemon]

Should have more than a dribble in the front filter .

Have you blown through the fuel lines with a compressor?

 

[Mikep]

Should have more than a dribble in the front filter .

Have you blown through the fuel lines with a compressor?

No I haven't Rich, thats not something I've thought of. I wouldn't be surprised if they have a lot of rubbish in them. I think I will replace them to be on the safe side.

 

[rockdemon]

Mine started conking out after a lay up and that fixed it.