ENGINE GURUS - First Spring Engine Start - Sum Ting Wong

Terry Stapley · #1 (**permalink**) 03-13-2008, 10:14 AM

418W - MSD 6AL - Pro Billet Dizzy - MSD Blaster Coil - Holley 750 DP

I started the engine for the first time since December last evening and it is not running right at all. The only winter projects I have done to the Cobra were new brake pads, some suspension stuff and I added a fan shroud!! No work on engine

Symptoms: Runs VERY Rough / Lots of Black Smoke from exhaust / Rear header pipes on both sides are not as hot as the front three, Pass. side rear tube is almost cool.
I did not have a lot of time to diagnose but I did pull the back drivers side spark plug and had it laying on the header as I cranked the engine. Very good spark. The plug was wet when it came out!!
I have 7 psi of fuel pressure at the carb and the engine was running fine when shut off in December. I added Stabil to the tank then also!
To me it seems like a fuel issue but I would appreciate any all advice as to what it might be and how to fix it!!

Chaplin · #2 (**permalink**) 03-13-2008, 10:19 AM

Are one of your floats stuck open? Look down the carb with the motor running and see if it is dumping fuel into the manifold.

RedBarchetta · #3 (**permalink**) 03-13-2008, 10:21 AM

I'd pull the needle and seat assemblies from both carb bowls just to make sure one of them isn't hanging open. Then re-set the float levels a little low to ensure you don't get an overly rich condition upon restart. Assuming that makes things better and you get a clean idle, then reset the float levels to their proper (higher) height.

-Dean

Ron61 · #4 (**permalink**) 03-13-2008, 10:22 AM

Terry,

Make sure that your needle valves and the float levels in the carb aren't stuck. I had that happen once in mine and even with the additive, they stuck. Took out the valves and cleaned them and everything was fine. The plug being wet would seem to indicate you may be getting to much gas to the cylinders, especially under idle and maybe flooding them.

Ron

Terry Stapley · #5 (**permalink**) 03-13-2008, 10:22 AM

I looked in the carb with the engine running (Roughly) and could not see any fuel dumping!! I also took out the sight plugs and the fuel level was at the bottom of the holes on both the primary and the secondary!
Thanks and sorry I forgot to put that in the thread!!
Any other ideas???

jhv48 · #6 (**permalink**) 03-13-2008, 11:02 AM

Pull all the plugs and clean them.

Reinstall and try again.

You have a fuel issue. If the floats are properly filled and not leaking, it should fire right up and clean up when warm.

If they foul out again, and they are getting spark, drain fuel tank, lines and float bowls, clean plugs again and then fill the tank with fresh fuel. Prime carb and then monitor fuel pressure to make sure it is not over powering the floats. Look into the carb throat using a mirror so your face isn't over the carb. Have someone crank the starter for you while you watch for excess fuel flowing into the manifold. Should fire right up and run right!

The only variable was the fuel additive. Probably the culprit!

mr0077 · #7 (**permalink**) 03-13-2008, 11:28 AM

And instead of cleaning the plugs, you might want to replace them, as a bad flooding condition will sometimes kill one or two (plugs).

undy · #8 (**permalink**) 03-13-2008, 12:21 PM

If you have a compression gauge handy I'd check that wet cylinder, just to be sure.

Dave

wtm442 · #9 (**permalink**) 03-13-2008, 12:28 PM

After replacing plugs, if you still have problem, take off the dizzy cap and wipe the inside so its clean and dry. Maybe some moisture inside. Then start engine inside garage with all lights off and cover any windows ... any sparks jumping from the wires?

DAVID GAGNARD · #10 (**permalink**) 03-13-2008, 12:42 PM

[quote=wtm442;824455]After replacing plugs, if you still have problem, take off the dizzy cap and wipe the inside so its clean and dry. Maybe some moisture inside. Then start engine inside garage with all lights off and cover any windows ... any sparks jumping from the wires?[/QU

zacctly, I've found with MSD distributors, the contacts on the inside of the cap corrode quickly and easily when left sitting for long peroids.....take off the cap and hit each connection with a small wire brush as well as the rotor, blow dry the inside of the cap and try it again...........at night...........

David

jhv48 · #11 (**permalink**) 03-13-2008, 01:16 PM

If that were the case, he wouldn't have spark at the spark plug. Which he says he does.

Start with the simple things first. Weed out the variable (additive) and go from there. If you get spark to the plugs (and no one has screwed around with the firing order) then it's a fuel problem.

It's always something simple!

How much Sta-bil did you add? One ounce for 2 1/2 gallons of fuel is recommended.

Terry Stapley · #12 (**permalink**) 03-13-2008, 02:49 PM

I added a 6 ounce container of Stabil into the 18 gallon tank!!

2.5 oz per gallon X 6 oz = 15 gallons treated!!

jhv48 · #13 (**permalink**) 03-13-2008, 04:04 PM

Check the firing order and make sure no one tampered with the spark plug wires and routed them to the wrong cylinders.

I'm betting someone put something in the tank that doesn't burn.

Do you have kids? Was the car covered completely? Drain the tank and see what comes out.

Kids have been know to "feed daddy's horses some sugar".

Terry Stapley · #14 (**permalink**) 03-13-2008, 04:14 PM

The only kid still living in my house is me!! At least that is what my wife says!!
I did recheck the firing order last night also!!
I will do a little more digging this evening!!

Jac Mac · #15 (**permalink**) 03-13-2008, 05:53 PM

Check your intake bolts - carb base bolts - bowl screws etc. They may have dried out/shrunk over the winter enough to create a low vac conditon / oil from valley etc or cause your PV's to stay open at low speeds.
Should clarify the shrinkage thing a bit- what really happens in a cold climate is the alloy parts shrink-allowing the bolts that retain them to relax there torque values.

Jac Mac

wtm442 · #16 (**permalink**) 03-13-2008, 06:34 PM

Quote:

Originally Posted by Jac Mac

Should clarify the shrinkage thing a bit ....
Jac Mac

Boy, are you leaving yourself wide open for a comment

Tim Brewer · #17 (**permalink**) 03-13-2008, 08:44 PM

My car does the same thing when it's time to change the plugs. I can always just "blow it out" on a straight-a-way and then it runs fine. But, I can tell you from experience, you can never clean plugs and expect them to last for any period of time. If you take the time to remove your plugs, it's easier to reinstall new ones.

Jac Mac · #18 (**permalink**) 03-13-2008, 11:27 PM

Quote:

Originally Posted by wtm442

Boy, are you leaving yourself wide open for a comment

Fools jump in where wise men fear to tread!!

Jac Mac

Rick Parker · #19 (**permalink**) 03-13-2008, 11:59 PM

Spray some carb cleaner in the small brass air bleeds at the tops of the carb main body. Also as stated, check the distributor cap for moisture that will create crossfiring.

trularin · #20 (**permalink**) 03-14-2008, 05:59 AM

IMHO, the car is blowing black smoke...there is too much gas. May I suggest:

1. make sure the choke is not too closed that no air is getting past it. After sitting for two or three months, it make stick.
2. Did it backfire when you were starting it? If yes, is it possible you blew the Power Valve check ball into the frame so hard that it has not let go? In other words, the power valve may be stuck open ( no vacuum ).
3. If the float levels were off or bad the gas dumps at the bowl vents. Is there gas there?
4. Once the excess gas is fixed, the plugs will be fouled. May I suggest you remove them and clean them/replace them.

Just my opinion.