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Failure on Initial Engine Start After Rebuild

Gadwhite

Senior Member
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We have an Austin Healey 3000 Mark 3 we just had the engine rebuilt and I'm having trouble starting it. I have good spark to all cylinders for my Igniter electronic ignition I have good fuel pressure to the carbs. I think my timing is good and I even pulled and reoriented the distributor Drive 180 degrees to make sure. I'm working with a fully charged battery so I don't think that's it but any suggestions anyone has would be great thanks.
 
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Re: trouble on 1st start

You may have good fuel pressure to your carbs, but are the float bowls full? Easy enough to pull the top and check.

If you've got spark at the plugs and the distributor is oriented correctly, it's pretty much gotta be fuel. Have you lined up firing of the #1 plug with TDC?


Keith
 
Re: trouble on 1st start

Keith thank you
I'll check the float bowls make sure they're full see what's going on there
I did a line up with TDC when I set the ignition
 
Re: trouble on 1st start

As Keith suggested i checked float bowls. plenty of fuel in there. any tips on checking spark strength? im now second guessing myself as my coil is old. I definitely have spark to all plugs, but now im wondering if its strong enough.
 
Re: trouble on 1st start

If your spark is strong enough to jump a 0.025" gap it's strong enough to fire a proper mixture. It's been pretty cold here in California--below 40degF for a few days :wink-new:--and Healeys are notoriously hard to start in the 'cold.' If you've cranked the engine a lot and not gotten a start, the engine should be flooded, in which case you should smell gas. If you don't, it's probably the cold start enrichment system which, in SU carbs, is a bit of a farce (lower the jets for a little richer mixture and increase idle speed). If you have some starter fluid give it a try, and if you get some cylinders to fire it's probably an issue with the enrichment system (you can't really call it a 'choke'). Don't overdo the starter fluid.
 
Re: trouble on 1st start

As Keith suggested i checked float bowls. plenty of fuel in there. any tips on checking spark strength? im now second guessing myself as my coil is old. I definitely have spark to all plugs, but now im wondering if its strong enough.

The spark should be a blue-white color if the coil is healthy. Orange is not good.

Good luck. Starting a new engine is always fun (no, really!). Jim
 
Re: trouble on 1st start

I recall that after my engine rebuild I also had trouble getting it started, eventually I consulted my Healey guru who directed me to rotate the dizzy whilst trying to start it. Eventually I did find the spot where it started to fire and worked from there. That was after I thought that I had timed it on TDC - turned out I was at least one sector out.

Just a thought - check your plugs to see if they are wet with fuel, that may give you an idea as to the root cause

:cheers:

Bob
 
Re: trouble on 1st start

Bob. Thank you. i have been trying to turn distributor a bit as i start. but you got me thinking. Im going to start from scratch and make sure I'm at TDC by physically checking #1 piston height through the plug hole.
 
Re: trouble on 1st start

Given that you have spark and fuel and that an engine is basically an air pump the other item is timing. I would go back to ground zero and check that you are actually at TDC by ignoring the harmonic damper markings and that #1 is at top when both valves are closed.
 
Re: trouble on 1st start

Bob. Thank you. i have been trying to turn distributor a bit as i start. but you got me thinking. Im going to start from scratch and make sure I'm at TDC by physically checking #1 piston height through the plug hole.

:encouragement:

Does the engine turn over with a "normal" sounding cadence? If not, it could be the firing order is wrong, or the camshaft is not timed correctly (unlikely, I hope!)

Check the plugs. If they are wet with fuel, check that the carb floats are properly adjusted, and that the float valves operate properly.

With the throttle closed, the throttle plates should be slightly open (the same amount).

If you don't already know this, you might look up the static timing procedure on-line, and set up the distributor by that method for the initial starting.

I've seen a couple of folks wire the distributor incorrectly because they weren't clear on which direction the rotor rotated.

If all seems to check out, it shouldn't hurt to use a small amount of starting fluid - just a puff into each carb - to see if it will fire.

Jim

Edit: Also, have you set the valve clearances?
 
Re: trouble on 1st start

Gadwhite

Take the valve cover off at the same time to ensure that you are at the compression stroke - should be according to the notch on the pulley but check anyway.
When I was 180 degrees out on a mini engine all I could get was popping and banging, then I remembered that I installed the drive gear to the dizzy whilst the engine was on its side with the front in the air on the bench. I used a length of rubber tubing to 'screw' into the hole of the drive gear, extracted it and turned it through 180 and off she went.

:cheers:

Bob
 
Re: trouble on 1st start

Here is the latest. Still no start.
New coil installed good spark ,
made sure plug wires in order,
and rotor in correct position at TDC. (Checked TDC through spark plug hole, and pointer on target of Harmonic balancer)
THEN
Switched distributor drive 180 and tried again still no start.
I think I may have flooded engine ( strong smell of gas, but no gas on plugs) so disconnected fuel pump and will try again tonight.
 
Re: trouble on 1st start

A brand new engine always seems to take more fuel to light off than a broken in one. Bob's suggestion of starting fluid (ether spray) is echoed here. If you don't have ether, trickle some raw gas down the throats, but get the open container away before you start cranking, in case your timing produces a backfire...

Are the jets low enough below the bridge? I'm guessing that a couple of turns down from flush__maybe 1/8"__is a good place to start.
 
Re: trouble on 1st start

Hold your thumb over the #1 sparkplug hole; when the compression blows it off, that's the TDC firing stroke. Make sure the rotor points to the cap's terminal with the lead going to #1.

Verify the rest of the leads: 1,5,3,6,2,4 and note the direction the distributor rotates (already mentioned). When you've tried and retried so many variations, it's easy to lose track of where you are. Take a breath.
 
Re: trouble on 1st start

Here is the latest. Still no start.
New coil installed good spark ,
made sure plug wires in order,
and rotor in correct position at TDC. (Checked TDC through spark plug hole, and pointer on target of Harmonic balancer)
THEN
Switched distributor drive 180 and tried again still no start.
I think I may have flooded engine ( strong smell of gas, but no gas on plugs) so disconnected fuel pump and will try again tonight.

Does the engine just crank over, or is there any popping or belching or any other indication that it is trying to start?

Where did you check the coil's spark - at the coil lead only? If so, you should also check that the plug wires are getting spark as well - maybe the distributor innards are malfunctioning. Jim

EDIT: Just re-read the thread and saw that you did check each plugwire for a spark. Hopefully that hasn't changed...
 
Re: trouble on 1st start

This caught my eye:

"I think I may have flooded engine ( strong smell of gas, but no gas on plugs)"

If there's no gas on the plugs after cranking the engine 'til you smell gas ... sounds like no gas is reaching the cylinders. And even the mightiest spark won't fire if there's no fuel in there!

Just my two cents.
Tom M.
 
Re: trouble on 1st start

I had trouble starting my car in the cold. The choke wasn't set correctly. Take the piston out of a carb and disconnect the choke cable. Move the choke lever up and down quickly and you should see fuel squirting out of the jet. This should tell you if the fuel is getting out of the float chambers. My jet didn't go down far enough for the fuel to squirt out into the carb. Have you tried some cold start into the air filters?
AJ
 
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