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Fuel delivery potential problemo

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vagt6

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Driving along the other day in my MK III '74 Midget, engine quits gradually and feels like fuel starvation. So, I pop the bonnet, pull the fuel line before the carbs and sure enough, no fuel was being pumped. So, I reached under the rear wheel and tapped the fuel pump with my hand, then turned the ignition key: the engine started just like the troubleshooting guides say. Drove home about 4 miles, no problems.

I plan to do the usual routine this weekend: test the pump electrics to ensure it's getting 12V; check the grounds, and then determine if it's the vented type (I've never looked at this pump before)and if so, make sure the vent's not clogged.

What else? What tests could I perform to make sure the pump is okay?

Or, could it just have been a clogged line that stalled the pump, and the pump's okay???

Thanks for the help, folks!
 
This an original type SU electric fuel pump?
How long since you've overhauled it?
New seals, diaphram, and POINTS?

Or is this a replacement sealed type of pump?
 
Don't know, I've never looked at it.

Will investigate . . .

Other ideas/suggestions welcome.
 
As TOC suggests, if it's an SU, they at some point will need either new points or cleaning and adjustment of the old ones. If it started working after a tap, that's quite likely the case. Adjustment of the throw-over point might be necessary too. It also suggests to me that it's an SU.

I have also experienced fairly new SU pumps to sometimes quit working when they get too hot.
 
Ahh, think two pumps and two switches. one quits switch on the second to get home.
 
Jack, the backup pump is a great idea. Might just do that if I have to replace this pump.

I'm referencing The Dave DuBois "SU Fuel Pumps and More" piece I found, it's very good (thank you, Mr. DuBois).

I jacked up the rear end and checked: it's an SU AZX 1307. The pump has "Negative Earth" posted on it, but my car is NOT negative, it's a MKIII positive ground. Go figure.

So, looks like it's time to pull the pump and check the points, etc. I'll try to tackle it this weekend, will let you guys know how it goes.

Further suggestions?? Any major stumbling points to know about with this job????

Thanks for all the replies, gents!
 
Why that looks just like Miss Agathas pump. $49 I think from my local parts store.
 
If polarity is wrong, when you order a kit, order for the proper polarity of the vehicle, NOT the pump.
My Jag was positively earthed, and in Singapore, when they added A/C they put in a Lucas alternator to handle the load and reversed the polarity for the alternator and the A/C fans.
When I pulled the pump out, there was a melted spot in the plastic cover where the diode or capacitor (depends on year of pump) used to be,
I got the right kit, rebuilt it as a spare, stored in the boot, for when the Facet dies.
 
Carter P4070. Around $75-$100, WELL made in the USA. You'll get your money's worth. 72 GPH and no reg needed.
 
My understanding is that if the pump has a capacitor, the polarity doesn't matter.

I was unable to fix the problem and thinking about sending it off to be rebuilt. Does Dave DuBois still fix these things?

Other rebuilder suggestions?

Thanks, everyone!
 
Last I heard Dave was still working on them but that was two years ago.
 
I tried the John Twist points cleaning exercise, pump doesn't seem to work properly. I tested it on the bench, it doesn't work every time I tested it. Cuts out intermittantly.

So, I sent Dave Dubois a message, here's his reply:

<span style="font-style: italic">First I'll tell you that yes, the pump can be restored and converted to solid state. My base price is $60 plus parts, with the average being around $110 plus or minus and my turn around time is 4 weeks. Now that I have told you all that, I am full up on pumps through the end of May, which is when I shut down for the summer. I can direct you to a gentleman who I recently trained on restoring the pumps and converting them to solid state and I supply him with the kits for the solid state conversion. His name is Slats Wolfe and his e-mail address is slatskars@comcast.net. I will let him know that you will be contacting him.</span>

Mr. Wolfe is located in WA, a bit too far for me in VA. Guess I'll order a new pump.

Thanks for the replies, folks. :yesnod:
 
Yes, think about this, Order a new one, and then have the old one rebuilt next fall or winter as a spare or to mount in tandam.
 
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