SU Carb leaking fuel

[D87 SMW]

With F170's original carb on the new engine, it has been relatively untunable and undrivable. The idle, mixture and timing were all sorted out, several times, but the car would still not drive without jerking about.

On acceleration there would be a struggle/delay and THEN it would speed up. Backing off, it would jerk again.

So, p155ed off at that and constantly ar5ing about with the tuning, I decided to stick the engine's original carb on, so I did that this afternoon. Running it, it was lumpy, blowing blue smoke out of the exhaust and p155ing fuel from the bottom of the carb.

Coming up with the theory that the mixture screw was too far in, thus causing a buildup of fuel in the carb, I backed it off and let the fuel drip out for a while.

When it was dry, I ran it again. Noticing it was still leaking fuel out of the bottom I backed the mixture off even more and it made NO difference to the running at all.

Is this simply a case of the carb chamber being full of fuel and it running on that? Will the new mixture setting ensure the correct amount of fuel going in once the build-up has leaked out/burned off..?

Or have I got another FUBARed carb on it now..?

The car is MOTd, insured for the year and taxed and I'm still not able to drive the bar steward!

:mad:

[G Force]

If petrol is leaking from the bottom of the carb and only the bottom of the carb then it is just that the large rubber sealing ring is leaking and needs the bottom of the float chamber removing to inspect it.

If fuel is leaking from the float chamber vent pipe then you need to strip the carb and fit a new needle and seat kit. GSU 104

[threelitre]

Regardless if it is the seal or the float needle - the carb will need to come off and be partially dismantled. When at it, that the chance clean it all on the inside. A leaking seal would not have lead to the car running badly, so something else must not be quite right...

Alexander

[G51 NAV]

Would it be difficult/expensive just to acquire a fresh carb which you know is working right? Or even a rebuild-kit? You seem to have been struggling to get than fresh engine to run correctly since the Dead Sea was on life-support :giveup:

[Austin-Rover]

I have a fair number of spare carbs you can rob parts from to cobble a decent one together if you fancy stripping yours down?

[D87 SMW]

Well, as G Force suggested, we took the manifold off (AGAIN) and replaced the seal on the bottom. It was indeed a bit crappy.

That sorted it! It was then tuned up and taken for a death drive by myself. It ran really well and went like a good 'en. It was that good, I told my dad to take it for a drive, too. So off he went...

Then came walking back.

:( :giveup:

I went round and we suspected no fuel, it had juddered to a stop after getting 2nd gear pulling out of our road. So off my dad went for fresh petrol. That went in, still no spark.

Then we found the connector from the distributor to the coil wasn't on! Hurrah, we thought, it should start now and we can drive it back. Mmmm, no. Still no joy when we put the LHD's coil on.

We've just had to push it back and onto the drive (managed to do so in reverse on the starter). The sodding ALTERNATOR must now be dead!

Please remind me why I shouldn't take my neighbours' and mother's advice and SCRAP THE BLOODY THING.

[/Rant]

[e692wtt]

Did you check for fuel coming through the feed pipe to the carb, in regular spurts, when the engine had died and it was cranked over? Did you check for a spark at the distributor end of the king lead, and if that was successful then at one of the spark plugs, after the engine had died and was cranked over? Is it something like the dizzy cap having worked loose after one of its clips came undone (this has happened to me on more than one A-series engine)?

I doubt you harmed the alternator, anyway - but prolonged running of the starter motor might possibly shorten its life. The battery will possibly need charging too, if the car was moved a fair distance on the starter motor. And there's no need to remove the manifold to strip the carb - it's possibly even more fiddly than removing the carb from the manifold, unless you're used to it.

Anyway, check the basics and get back to us :) . There has to be a problem causing this issue somewhere.

[D87 SMW]

The battery is from the LHD (F170's is on charge, again...) and was kicking it over first rate. After finding the connector had come off the dizzy, we thought it'd fire up, but still no.

There was defo fuel getting into the carb when it was lying beached at the roadside. There was just no spark at all.

The issues with the leaky carb were sorted and it was tuned up and driving as good as ever. I really thought we'd cracked it and got the car drivable again. This new problem has to be something else, it always had spark before.

The problem isn't that disconnected dizzy and it isn't the coil, because the LHD one had no effect.

I'm just fed up with all of it. First I knew I need to replace the engine, then it had to be welded at the sills for MOT. Then it needed the gear linkages adjusting under the car after the new problem it threw at me, crashing out in public. Then it needed the carb replacing because it was undrivable/untunable and I ended up with a leak on the new one. Now, yet another problem has occurred, showing us all up.

This is without the insurance cock-up, the delay in getting the papers through from another insurer, the threats I've had from neighbours, amongst other things - I'm ready to jack it all in. Try and do it some good and it repays me by throwing new problems at me each time. Useless pile of cack.

[D87 SMW]

I've just gone out and checked it all over. I turned the connector on the dizzy upside down and felt a satisfying click, so turned it over and it fired up straight away.

Took it for a death drive and it did exactly the same as it did for my dad: pulling away from my road and into 2nd gear and it juddered to a halt. Knowing what this had to be, I clipped the connector back onto the dizzy and brought it home.

Quick investigation found that, when getting 2nd (or 4th) gear, this happens:

http://i226.photobucket.com/albums/dd179/N207ENE/DSCF4071.jpg

The linkage moves across and strikes the connector, soon causing it to pop off and cut the spark!

I can't move the distributor or the linkages elsewhere, obviously, so what do I do?!

:confused:

[G Force]

Hi Steve It is the distributor position that looks wrong. If you have set the timing with a timing light i.e. 12 degrees BTDC @ 1500 rpm with vacuum disconneted and plugged. Then the distributor drive gear is fitted in the wrong position or the plug leads are in the right order but in the cap the wrong position. If you set the timing by trial and error then try retarding the timing (dizzy anticlockwise) a little at a time until the connector is clear of the linkage. Assuming the timing is too far advanced at the moment you should not get a noticable drop in performance by just retarding it a little.

[SimonR]

I've just gone out and checked it all over. I turned the connector on the dizzy upside down and felt a satisfying click, so turned it over and it fired up straight away.

Took it for a death drive and it did exactly the same as it did for my dad: pulling away from my road and into 2nd gear and it juddered to a halt. Knowing what this had to be, I clipped the connector back onto the dizzy and brought it home.

Quick investigation found that, when getting 2nd (or 4th) gear, this happens:

http://i226.photobucket.com/albums/dd179/N207ENE/DSCF4071.jpg

The linkage moves across and strikes the connector, soon causing it to pop off and cut the spark!

I can't move the distributor or the linkages elsewhere, obviously, so what do I do?!

:confused:

Steve,

This very same thing happened in my first ever Maestro - a G-Reg 1.3L. I never did solve the problem. It's interesting to hear Gary's comments now though. Sounds like that would have fixed it.

I wonder if it's do do with the fact that the car was built for 4-star and now with the timing altered for unleaded it's a problem.

Good luck fixing it.

[D87 SMW]

I don't know what's going on, at all. Backing the timing off to allow sufficient room for the linkage makes it run like a bag of the proverbial.

Currently it runs fine, but going for 2nd knocks the connector off.

Would turning the distributor 180 degrees solve it? Apparently the engine is timed that way to start with. The timing mark is at BDC rather than TDC. :confused:

I just can't bloody win with it at the moment. :mad:

[G Force]

I don't know what's going on, at all. Backing the timing off to allow sufficient room for the linkage makes it run like a bag of the proverbial.

Currently it runs fine, but going for 2nd knocks the connector off.

:

Ok then Steve then it either the drive gear or the lead position. Is it possible for you to take a photo showing the distributor and the plug leads and where the leads connect to the plugs in the same shot, and I will try work out the best way to proceed?:)

[D87 SMW]

Gary, I can do that, yes. It is chucking it down now, though.

Are you going to suggest moving the dizzy round 1/4 turn and then relocating the HT leads onto it accordingly?

[G Force]

Gary, I can do that, yes. It is chucking it down now, though.

Are you going to suggest moving the dizzy round 1/4 turn and then relocating the HT leads onto it accordingly?


Yes that was the plan but I did want to make sure you could time it up ok without the vacuum unit fowling the oil fillter. and also to see if you had standard leads, because sometimes if the drive is in wrong and you just try moving round the leads, with standard leads 3 & or 4 are too short.

If you are happy and ok to go ahead and just try, then ok dont bother with the photo.

I was just going to consider the merit of either option the drive relocation or the leads.

Cheers Gary:)

[D87 SMW]

Many thanks, once again, for your advice, Gary. :)

I have successfully turned the distributor and relocated the HT leads into the next terminals along. The gear linkage is nowhere near the electrical connector as that is now facing upwards on the right of the dizzy.

So I've just taken it for a death drive and I am, finally, pleased to say that it was successful!

:hat: :banana: :driver: :woohoo:

[G Force]

Sweet:cool: hope all goes well from now on.:)

Cheers Gary:)

[ChrisM]

At last, Steve, well done :D Coming to Longbridge in it now tomorrow? ;)