Thread: 1976 S3 Petrol 'Surging/Hopping' Up Hills & 'Cold Start' Question

Hi Don, id also be checking float level if its only happening while going up hills etc.

Cheers Rod

You can take the feed line off the bowl and simply blow all the remaining crud out before you flush the tank, This should clean the system out nicely.
Like you said the pump fills the bowl nicely so I don't think you have a pump problem or a blocked delivery pipe so you problem is forward of that.
Have you replaced the paper filter with a new one as this may be contaminated and may even have water in it that will restrict the fuel flow?
If you take the carby off dismantle it including the jets and give it a real good clean out as imagine that there will be plenty of "Nasties" in there, Maybe the fuel bowl in the carby is simply so full of "Gunk" it cant hold enough fuel and it doesn't hurt to give the carby a once over every now and then anyway

Originally Posted by 67hardtop

Hi Don, id also be checking float level if its only happening while going up hills etc.

Cheers Rod

Will do! Has been mentioned several times now so will definitely get to that as well. Will clean out the lines first and then look into how to work on this MASSIVE carb.... Compared to my bikes, anyway.

Originally Posted by JDNSW

1. Poor running up hills. I have had what looked like fuel starvation that turned out to be the points had closed up, and other things that give poor ignition could have similar effects.

This exact thing happened to me the other day.

Coughing & spluttering up hills.

Turns out the points were always closed as they were well worn.

New ones fixed it immediately.

Originally Posted by Cannon

This exact thing happened to me the other day.

Coughing & spluttering up hills.

Turns out the points were always closed as they were well worn.

New ones fixed it immediately.

I'll be moving on to ignition after I test the fuel theory, who knows, could be a combination of both. 90% of carby issues are electrical, and vice versa! Perhaps this one's 50/50

A spare 20 minutes after work, before getting dinner ready for The Kid, allowed me to investigate the fuel pickup and sender. Gasket sealant everywhere! It was hard to find an actual gasket in there.

You can see gobs of sealant all over the sender unit. Much of it had never cured so I imagine much more has fallen into the tank. The rod of the sender looks like it's been soldered and wired together. A home made job?
846_IMG_20170404_164724.jpg

Here's the "gasket" for the fuel feed elbow. The screws had pushed sealant into the tank.
851_IMG_20170404_164206.jpg

Ummm, so there's the filter on the end of the fuel pickup pipe.
567_IMG_20170404_164351.jpg

A quick look in the tank, with a candle lighting my way, shows quite a bit of debris at the bottom. No surprise there.
Managed to squeeze in just enough time to make a gasket for the fuel pickup elbow. Will the old practice of a smear of grease on either side be enough? Or should I be using a fuel resistant sealant?

Well there's 20 minutes gone, time to get back to domestic duties. Will pick up a new element for the AC Delco fuel filter on the way home tomorrow and might get another few minutes to start draining the tank.

Not a bad effort for only 20 min work there Mate
A decent gasket without the wrong sealant will fix the top of the tank but that filter is RS.
If you have to you can knock one up out of a bit of stainless or brass flyscreen and it will do the job.

Hi Don,
if you have a long range tank, ie 16 gallons, or if u like the little ones 74 litres, the usual fix for the sender unit was to extend it, by cutting it and adding a length of wire in between, then wiring it together to hold it and soldering it too. Some ppl dont realise that silastic doesnt cure when petrol is involved. So its probably in the tank and blocking stuff up. I used stag sealant on my fuel gaskets. It works well.

Cheers Rod