Vikram's 1960

Started by 94touring, May 15, 2016, 11:55:37 AM

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Vikram

I tried firing my car today, no luck. I have fuel going to the weber an I can crank the engine no problem. I pulled a spark lead off and cannot see a spark. How do I go about checking my ignition coil?

94touring

You had a cluster of wires on the inner wing and one of the connections was touchy.  Make sure they're all tight first.  One of them kills the ignition and had a large spade on it.

Vikram

So I ended up buying a new ignition coil (unballasted 12V) after I confirmed that the old coil was getting voltage. After installing that and a little fiddling, I got a spark. The engine eventually fired and idled for about 10 seconds before it died, this happened consistently. It would fire seemingly easily, but die soon after. After multiple attempts, a small cloud of white smoke would puff out of the velocity stacks (I think this is fuel vapor and certainly smelt like it).

As a reminder, I am running a Weber 45 with electronic ignition, new spark plugs and a 2-2.5 psi electric fuel pump. I have confirmed that fuel pumps out at a consistent rate into a jerry can.

What could be the issue? The weber is mounted at a slight angle from true horizontal so maybe floats? Or is it fuel mixture (how would I adjust this)? Timing? All of the above?

MiniDave

If it starts and runs for 10 sec then dies, it sure sounds like it's running out of fuel.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

How long has it been sitting?  Modern fuel tends to start breaking down and going "gummy" after sitting for a couple of weeks or so.  It may have clogged some of the ports/jets of the carb.


Vikram

The fuel is definitely old, I did not realise that it would be an issue .

But my timing is definitely pulled back, I have heard Webers need 12 degrees and I am probably at 9.

That might be the issue.

But in addition could it be the level of my floats as well?

MiniDave

It's not the timing, it's sounds like a fuel issue - like maybe the float valve could be stuck open just enough to let a dribble of fuel in, but not enough to keep the engine running, each time you shut it off residual pressure fills the float chamber enough that the engine can run, but not enough to keep up, especially when cold and on the choke.

That's my guess

Have you ever had it running successfully on the weber?
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Vikram

Nope, never had it running smoothly. First time breaking it in.

Vikram

Drained the tank and put new gas in.

Pulled off the top to look at the floats. Looking inside the weber you can see the different levels of gas inside the two chambers due to the angle of the carb.
Do I need to adjust the floats to account for this?

Willie_B

Steve Gibbs, coopertune on minimania, Does a lot with weber carbs. You might try emailing him for help.


jlgibbsrealtor@aol.com


Vikram

Thank you, I reached out to him.
Is the uneven fuel level going to be an issue?

MiniDave

If the rear chamber is the primary side of the carb, that will definitely be an issue, there is not enough fuel in there to keep it running from the look of it.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Vikram

To fix this would I need to bend the rear float down to account for the lower fuel level?
Or is the only option to have the carb perfectly level?

MPlayle

I am not familiar with the Weber side-draft carbs; however, the DGV I fiddled with a bit on the green Van had a similar looking float chamber.  There was only one fuel inlet into the chamber and the floats were joined.  That would mean whichever side was higher would cut off fuel entering both sides.

As much angle as appears to be present in the picture (may be an optical illusion), attempting to offset the floats may not be enough to compensate as the front chamber looks like it would end up flooding/overflowing.

Most Weber side-draft installations I have seen pictures of seem to use a manifold that gets the carb fairly level.

Vikram

In addition to posting on this forum, I posted on TMF.

Turns out it is just one float chamber and that the angle should not be an issue. I might have to adjust the floats overall to ensure that the needle is closing.

I was also advised to run with the top inspection cover off to see if the pump jets are working? Is this safe/good advice?

Lastly, they suggested that my timing was way off and to use a bulb over the ignition coil to set this. Anyone how I would go about doing this?

MPlayle

They are recommending you perform a "Static Timing" on it.  do a google search of "Static Timing" to get several good articles and videos describing the procedure.

Running the engine stationary with the inspection cover off the carb has some risk.  I do not know enough to say how much risk.

Vikram

So it turned out to be the floats. I filled the bowl full, disconnected the fuel pump and tried to fire it. Started right up. So I adjusted the float and now it runs on its own just fine. Throttle response is good and smooth.
However it does have a couple of issues. It's backfiring through the carb and popping loudly,  and does have quite a high idle.
Is this now a timing issue/running too lean?

Vikram

Just rechecked the floats, and raised them a little to ensure that its not overfueling. Advanced the timing, and the backfire through the carbs has stopped. But the idle is crazy high something like 3-4k. Vacuum leak between the carb and manifold? Im using misab plates but Ive heard overtightening it can pop the seal out. Might have to pull the carbs off and investigate. Thoughts?

Vikram

Pulled the carb off again, loosened the bolts for the Misab plates between the carb and the inlet manifold. Torqued them down less and ensured that there was a good seal. Once back on the car the idle is still ridiculous. I'm pretty sure it's not an air leak.
When the car was running, I shut off the fuel pump and the revs came down until it finally died when the bowl was empty. So I think it's an overfueling issue? Maybe I adjusted the floats to allow too much gas into the carb and it's just bypassing the jets and raining down the barrels?
I really don't know. Will try adjusting the floats tomorrow.

94touring

Is there an idle adjust? Because you're getting too much air.  Too much fuel would flood it and it would die never to start again till the plugs are cleaned or replaced.

Vikram

There is an idle adjust but it's not enough to drop the idle by that much.
Where could the air leak be from? Inlet manifold to the head? I'm pretty sure it's not between the carb and the inlet manifold.
The vacuum line from the distributor is open, could that be an issue?

gr8kornholio

Trick I've always seen is to spray carb cleaner around seals and vacuum lines. If the idle increases you have a leak.
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

MPlayle

Vacuum line for the distributor will contribute significantly if not capped off at the carb or connected to the distributor.


Vikram

So should I just block it off directly at the distributor? Webers don't work well with vacuum advance

Vikram

I also just realised something. My crank case breather line is wide open, couldn't this be a huge source for a vacuum leak? Should I connect it to the timing cover breather which is currently blocked off?