• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

SU Fuel Pumps: diagnosing?

Share this page

RichC

RichC

Senior Member
Offline
Since I'm not an expert at the 'rat-a-tat-tat' fuel pumps and have a 75 MGB with one that will not pump ... I proceeded to purchase another. BTW ... have done the electrical checks and switch under the dash and all is fine ... I think. (about 11 volts) I installed the new pump and turned the key to hear the quick 'rat-a-tat-tat' noise for about 2 seconds before turning it off. All was looking good.

Next put new fuel in the NEW tank, check all my lines and turned the key until the pump turned off. Looking good I thought. Next was to fire up the car in which it did only to stall after chugging for about 5 seconds. (first since '92) After attempting a restart and realizing that I was not getting fuel began to diagnosis the system. I took off the new fuel filter (full of gas) and attempted to let the fuel pump click some fuel into a can. Nope ... wouldn't come on. Recheck electric and took off fuel lines again blowing them out to see if something has plugged ... didn't.

I've now got the two fuel pumps in front of me and am trying to figure out what to check? Putting 12 volts on either pump results in the same thing ... silence. Your thoughts?
 
I would check the points on it. When I installed a new pump on my 75 to replaced a failed pump it didnt work at all. Once I cleaned up the point off it went and has been working fine.
 
Greetings,

In the FWIW category....

When I bought my MGB the PO's father-in-law still had his 1977 MGB. He told me that if the fuel pump does not "chatter" when you turn the key give it a gentle tap on the body where it is attached. Got a rubber hammer just for that. Knock on wood, I have not had to do this...yet.

He could not say what the tap did, but he has had to do that with his MGB. Perhaps it "adjusts" the points. /ubbthreads/images/graemlins/wink.gif
 
Haha, my dad told me to do that while back and it actually worked. I think it knocks off the corosion on the points if it has been sitting for a while....
 
Years ago I had a 68 B that did the same thing. I carried a hammer in the driver's compartment. When it didn't start/click, I'd lean out and whack it until it started clicking.

Wow! I really miss that B! /ubbthreads/images/graemlins/frown.gif
 
Follow up on the fuel pump. First I took out the pump and since it was brand new decided I had better not peel the Blue band off in hope of an exchange for one that worked. Second I took apart the old corroded one and clean it up, dielectric greased it, steel wooled the contacts and reassembled. It is 'ALIVE.' Next figured a rubber hammer wack or two to the 'brand' new one couldn't hurt and guess what ... back to life again but it purrs faster than the old corroded pump. Perhaps reassembly tonight???

Thanks guys.
 
Just an update ... I'm now an expert at the SU fuel pumps. /ubbthreads/images/graemlins/smile.gif Took both apart and freshed with anti-corrosion electrical spray and a little steel wool.

Tonight reinstalled, pressure was up without a leak and the sleeping 'B' is alive and purring like a kitten after 14 years asleep. Felt really good. (when I feel a little more comfortable I'll share the 'bonehead' thing I did) /ubbthreads/images/graemlins/crazy.gif
 
FWIW
on a grim note, there was a blurb on the news last night about a young lady in my area that was run over by her own car because she "carried a mallet in the car and would crawl underneath to tap on (something) to get it to run"

My first thought wasn't "how tragic", but rather "huh. she must have had an MG."
 
Congrats on the rebuild(s), lessons learned, and of course Waking your sleeping Beauty! /ubbthreads/images/graemlins/cheers.gif
 
Back
Top