Chevy won't start

[Warren]

I think I have been looking at this too long and can't see the wood for the trees.

I have a book, showing the number 1 cylinder post on the HEI dizzy as being the second clockwise from the square bit where you connect the positive. With number 1 lead connected here I have to turn the distributor body so far anti clockwise the vacumn is pointing straight up the engine. This is the only position it that the engine even sounds like its going to catch.(did actually run for about 5 seconds in this position)

If I move the leads around and treat the first post on the cap as number 1 at least the rotor lines up when the engine is set to 8 Deg BTDC. The vacumn is also in the more normal 45 Deg across the engine.

Bugger still won't run. It does try to catch and when you feel the headers there are only 3 or 4 that feel warm and I am wondering if its possible the coil is breaking down and not providing spark.

Sorry its a bit like war and piece, any suggestions.

Warren x(

[tonyevans]

See attached zipped word doc with the firing order and distrib. of my Chev 350

[SimonP]

Here's a pic:
http://www.cobraclub.com/crcforum/user_files/4553.jpg

Ensure your engine is sitting at TDC on the compression/firing stroke of cylinder 1, then check that the rotor arm is pointing to that cylinder's High Voltage Turret (Mark this on the distributor baseplate with a sticker or marker pen).

If not, you will need to remove and refit the distributor, turning the rotor while it is out to get them to line up.

Note that the rotor will turn as the distributor is removed and refitted, and that you will need to turn the oil pump drive round so that the keying on the distributor will line up as it is refitted.

Since I've had an adjustable advance can fitted, the distributor sits at almost 90 degrees to the engine, ie "straighter" than in the pic here.

Hope this helps,

Simon.

[Warren]

Hi Tony

Can you mail it to me, for some reason I can't get at it.

warren.senior@terrington.co.uk

cheers
Warren

[Warren]

Guys

I seem to have things correct, what do you think to the idea that the coil might be breaking down.

As some of the headers are hot I am wondering if the charge is not building in time so its trying to run on four cylinders.

Cheers
Warren

[SimonP]

Warren,
Things to check:
1. Disconnect the tach wire, see if this makes any difference. If it does, you may have the wrong option used on the tach instrument wires or dip switch settings.

2. Is the HEI unit getting a good power supply? Check when cranking - a test lamp is good enough for this purpose if you haven't got a meter. Ensure no ballast resistor is in circuit!

3. Check the spring loaded carbon brush in the centre of the distributor cap is present and undamaged.

4. Check continuity of ignition (spark plug) leads. Does the centre core touch the brass/tinned terminal at each end?

4. There's a slight possibility the coil is breaking down, but are you 100% sure it's not a fuelling problem?

Work the throttle - are your accelerator pump jets squirting?
If not, open the throttles a bit more and chuck a capful of unleaded down each primary venturi (dual plane manifold) or just one (single plane manifold). The engine should fire and run for a few seconds.

Interesting that you mention only 4 appear to be firing - are these 4 by any chance on the same "plane" of a dual plane manifold?
That would point to carb adjustment....

Simon.

[SimonP]

Also make sure that you have all un-used vacuum ports blocked off!

Simon.

[Warren]

Already disconnected the tacho wire and run a permanent feed to the + direct from the battery.

Checked fuel supply and all plug leads, got sparks at leads so assume carbon brush OK.

Not tried chucking capful down the throat yet but will give it a go. Last time the car ran was the 45min break in for the cam, I am beginning to worry that I haven't done that right and knacked it so will remove rocker covers and check everything is going up and down OK. I would still expect it to run though, just rough.

The only header getting warm during any attempt to fire when cranking is number 6.

Warren x(

[choogh]

Warren,
I have exactly the same problem as you when I first fired up the engine, the solution, given all the abvious factors have been addressed was to smear a bit of Vaseline inside the spark plug end cap, made the leads slide and fit over the spark plug you could "feel" them go onto the plug.. Worked like a dream thereafter.
Charlie
:tu :tu :tu

[Warren]

Current Situation

I decided to go back to square one. Pulled of the rockers, distibutor and went back to check tappets and engine position from scratch. I was concerned I may have knacked the cam when I broke the engine in.

These are hydraulic tappets and they all needed half a turn to set them correctly. (I can't believe that I have worn down a new cam exactly the same amount on each tappet) After doing this I checked them again and they felt like they needed adjusting even more, (couldn't understand that). Anyhoo set the engine at TDC, but the dizzy back in and proceeded to rip out the plugs. Some where very wet so I dried them all, rechecked all the gaps (new plugs anyway).

All back together I turned over the engine and checked EVERY plug for a spark. Turned engine to 8Deg BTDC as directed in the book and went for it. Rotor lined up perfect.

Nothing at first engine just turned over, I didn't want to drown the plugs so I was cautious with the throttle. Once I got a little fuel down one or two cylinders fired but I also got a large backfire through the carb. (well aware I can damage the thingummy on the Holley with a backfire) This kept happening so I started to turn the distributor anticlockwise bit by bit and retrying. Kept getting the backfire and suddenly the engine caught and revved to what sounded like somewhere between 2,500 and 3,500 revs and stayed there. (still have tacho disconnected)

It was getting late so I will check throttle/idle not set to high today. Any other suggestions for why the engine should go from intermittent backfire to what sounded like perfect 8 cylinders action would be appreciated. (All headers got hot so they must have all fired)

Thanks for the help so far and for bearing with me.

Warren