New guy here and owner of a '71 Etype SIII 4 speed 2+2 which has me tearing out what is left of my hair.
I’m hoping there is a way to do this. I am SO done messing around with the fuel pump on my '71 SIII. Is there an aftermarket replacement available? I have tried electric fuel pumps on different cars in the past and been treated to the most ungodly noise from the rear of the car, causing me to go back to the mechanical pump on every one of them.
Now I am trying to get this family heirloom of mine up and running again. Does anyone make an improved pump for our cars?
I’ve started using a Hardi 9912 fuel pump. Physically nearly the same as an S.U. Made in Germany, still ticks like the S.U. no troubles yet. Not a lot of miles on mine, but a customer has had one for a few years now with no issues. Search e-bay. I believe it is slightly smaller in diameter and the inlet and outlet ports are at slightly different positions.
Craig
If rebuilt with new parts and set up properly they are very very reliable.
What has been the problem with the SU in your car?
Dennis
69 OTS
(I rebuilt my pump in 2001 and then in 2019)
I have to agree with that! Never really had an issue with an S.U. pump until recently. Bought the Hardi as a spare for my MGB and ended up putting on my E Type only because I had it. I’ve never tried to rebuild a pump yet because we’ve always had so many spares. That being said, the ones i have had issues with, i’ve taken the points out, filed them, put it back together and had no more issues.
I have an original 1971 fuel pump and it still works fine. But I used to have lots of issues all related to the setting up of the points that carry heavy amperage and can burn. I converted it to electronic by adding large transistors to the existing pump. The points are still there but no longer have high amperage flowing through - just enough to fire the transistor.
This is a great idea. Did the transistor fit inside the cap? With its heat sink it looks too big to fit inside.
But wow. No points wear due to arcing for sure
You should start a new thread titled
“Guaranteed way to stop your SU pump points from wearing out due to arcing”
Dennis
69 OTS
Most of the fuel pump issues that I have had are due to actual trash in the tank and not the fuel pump…make sure your tank is clean and put back the original SU pump, you will not have a problem. Also make sure someone has not added additional fuel filters along the way. The existing fuel filter on a V12 works fine. Jeff S.
Agreed: the original SU fuel pump, equipped with a modern electronic switching, rather than the points, is actually a pretty robust piece of engineering.
In my experience the problem on V12 cars is not the fuel pump, but the earth connection in the wiring loom for the fuel pump, You can not easily detect a bad earth with a modern digital multimeter. The original (rebuilt) SU pump has worked perfectly (even at 140+ mph) in our V12 OTS #1S20183 since I opened, cleaned and applied battery grease to the earth connection inside the RH rear wing (fender). YMMV.
I ve tried a few over the last 22 years incl original SU. Electronic SU, Carter and a few more. Without a doubt the best so far is this one from Jegs. The noise of the Carter was driving me nuts. The electronic SU lasted a few months before the board melted down
Cheap, quiet and so far so good in 2 1/2 years and 10k.
Yes as someone mentioned check the ground. Make sure there is a solid unpainted connection to the sheet metal.
I have also installed a fuel pressure gauge under the left side of the steering wheel. Great troubleshooting tool.
Finally I have installed the new pump inside the spare wheel on the boot floor. The original location is awful making any troubleshooting difficult. It s also to exposed to any collision.
Pekka, I am not sure exactly how you are checking. IMO, if you are checking for resistance, no meter is good at checking for poor grounds. If you are checking voltage, then any decent meter should be fine.
Tom
Does it still have the fully mechanical SU with points? The new SUs come that way or electronic without points. The new style are quite a bit more reliable in my experience so long as you aren’t sucking a ton of rust out of the tank. They make the same exact sound too. If it’s still the original tank you should install an inline filter before the pump. This way it will still use the same plumbing and wiring and mount system.
No filter before the pump! A filter before the pump drops pressure and can create vapor lock, especially in warm weather. All that you need before the pump is a stock screen in good condition.
Pekka, I am not sure exactly how you are checking. IMO, if you are checking for resistance, no meter is good at checking for poor grounds.
Yes you can very easy with any volt meter
Place the meter in parallel with the circuit you are testing or joint and power the circuit
A voltage reading over .3 volts indicates a bad connection a good single connection .1 volts or less
You can test one connection or ten all at once
3 good connections in series would be .3 volts
This is very effective I use it a lot
Cheers jim
Hi Craig…the S3 has a twin SU pump…note that useing a single pump SU will cause fuel delivery problems. …a friends S3 would just not run right when one of his pumps intermittantly stopped working…so just make sure that you use a double pump or if you go aftermarket that it can deliver the same flow/pressure as the correct S3 pump…Steve
Jim, if you are going to quote me, please read the my quote first. You make it sound as if you are disagreeing with me, then say the same as I did, plus details.
Tom
