Author Topic: Bad initial timing or intake leak?  (Read 546 times)

Offline SFRT - Frenchy

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Bad initial timing or intake leak?
« on: May 24, 2010, 10:50:41 AM »
http://www.youtube.com/watch?v=8JymZ5gKEAE

Droped my new chryler 360/727 transmission for my 72 Dodge Monaco. I initially set #1 @ TDC (aligned the timing mark with 0), and matched the #1 tower of the distributor with the point.

Engine started but ran very ruff and wanted to die at idle.
I retarded the idle so much that the timing mark now sits about 12 o'clock on the balancer. Engine now maintains idle with some little coughting every 10 secs or so.

When I shift in gear, the idle takes a crap and I have to throttle up for the engine not to die.

As far as Vaccum goes, bottom back of carb is pluged to dist vacc advance, bigger bottom back of carb tube is pluged to PCV valve, and brake booster is pluged to back of manifold intake. All other vacc port on the carb are pluged with a cap.

I have not sprayed some brake cleaner around manifold intake to check for leak, do you think I messed up my intake install or it's a really a timing issue like I should remove/reinstall my distributor because I miss the cam gear matting by a couple of teeth.
Dat jugs bro.

Terror flieger since 1941.
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Offline Captain Virgil Hilts

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Re: Bad initial timing or intake leak?
« Reply #1 on: May 24, 2010, 11:58:18 AM »
Bring number 1 cylinder to TDC on the compression stroke, then move the timing mark to about 20 degrees before TDC by rotating the engine backwards. Drop the distributor in, aligning the rotor with the number 1 terminal on the cap. Turn the key on, but do not crank or start the engine. Place a spark plug in the end of the number 1 spark plug wire, grounding the body, make sure the coil wire is in the cap. Now, rotate the distributor in the advance direction, and make sure a spark occurs at the plug in the end of the wire. Do this 3-4 times to make sure you have it right. Turn everything off, hook everything up, then try starting it. It should be spark timed well enough to start and idle, and you should be able to set the timing to about 12 BTDC at 700 RPM or so, and it should run fine. If it doesn't, you have a vacuum leak, a wiring problem, or a carburetor problem.
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Offline Shuffler

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Re: Bad initial timing or intake leak?
« Reply #2 on: May 24, 2010, 12:03:22 PM »
Always before top dead center on compression stroke. (TDC when valves closed)

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Offline SIK1

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Re: Bad initial timing or intake leak?
« Reply #3 on: May 24, 2010, 12:09:07 PM »
Put a vacuum gauge on it and use this site http://www.earlycuda.org/tech/vacuum2.htm as a reference.

Make sure that you hook the gauge up to a non ported source. Vacuum gauges are a valuable diagnostic tool and can tell you a lot about the condition of your engine.
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Offline SFRT - Frenchy

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Re: Bad initial timing or intake leak?
« Reply #4 on: May 24, 2010, 12:35:35 PM »
I'll try ur stuff this week end Virgil, meanwhile have you seen the attached vid? What do u think? BTW why setting the mark at 20 BTDC for the spark, the hood decal says 0. (I know u know better than a decal hehehe)

 My #1 TDC was set on the compression stroke, it'll probably not be runing if it was set on the exhaust stroke.

What I'm wondering is why the engine cannot take a load (see video). My carb is a 2BB Holley reman from Autozone straight out of the box. I did not monkey with the mixture settings. Maybe the "factory setting" is off, but isn't the mixture setting only for idle anyway?

At any rate, I should really install new spark plug wires  :uhoh

True SIK, I'll do that too. Engine is a brand new long block from Evergreen, I'm pretty confident the condition is ok. Have new carb, dist, plugs. Factory elect ignition and balast resistor were not replaced, but everything ran on old engine when I removed it. I'm not mechanic, just took everything appart while reading books so I could learn more about cars. Getting close to getting this boat on the road  :cheers:
Dat jugs bro.

Terror flieger since 1941.
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Offline SFRT - Frenchy

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Re: Bad initial timing or intake leak?
« Reply #5 on: May 24, 2010, 12:46:45 PM »
BTW, I read somewhere to unplug the dist adv line when u set ur intial idle timing. I did mine with the line pluged to the dist adv, is that no good?
Dat jugs bro.

Terror flieger since 1941.
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Offline SIK1

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Re: Bad initial timing or intake leak?
« Reply #6 on: May 24, 2010, 01:31:44 PM »
The reason I suggest a vacuum gauge is because it can indicate a number of minor issues such as incorrect initial timing, intake leak, improper distributer timing, as well as serious mechanical issues like burned valves, worn rings, and blown head gaskets. All with a very simple hook up and operation.
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Offline SFRT - Frenchy

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Re: Bad initial timing or intake leak?
« Reply #7 on: May 24, 2010, 01:50:18 PM »
Indeed.
Dat jugs bro.

Terror flieger since 1941.
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Offline Captain Virgil Hilts

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Re: Bad initial timing or intake leak?
« Reply #8 on: May 24, 2010, 03:10:45 PM »
Twenty degrees static spark timing because it is always retarded slightly from running timing. Those remanufactured carburetors are junk, plain and simple. Get yourself a good used core from a junkyard and take it to a good carburetor shop and have them build it.
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

SaVaGe


Offline oakranger

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Re: Bad initial timing or intake leak?
« Reply #9 on: May 24, 2010, 03:47:59 PM »
Do i hear a taping sound at the last 10-15 sec of that footage?
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Offline oakranger

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Re: Bad initial timing or intake leak?
« Reply #10 on: May 24, 2010, 03:51:15 PM »
Do i hear a taping sound at the last 45 sec of that footage?
Oaktree

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Offline kamori

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Re: Bad initial timing or intake leak?
« Reply #11 on: May 24, 2010, 07:00:52 PM »
Off by 1 tooth?

Offline eddiek

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Re: Bad initial timing or intake leak?
« Reply #12 on: May 24, 2010, 07:51:25 PM »

Go back to basics......double check your plug wires, make sure they are hooked to the distributor in the correct order.  Just listening to it, that would be the first thing I did.  Sounds like you have two wires on the wrong terminal to me......
Regardless, it will be something simple, just take your time and go back over everything, Frenchy.  Good clean install on that engine, by the way!   :aok

Offline CAP1

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Re: Bad initial timing or intake leak?
« Reply #13 on: May 24, 2010, 09:43:05 PM »
sounds like timing is way off. i'm not familiar with theway virgil told ya to time it......but comin from him it has to be good........

i had always "bumped" the engine while holding my thumb over the spark plug hole for #1(or use a compression gauge). once you show compression, use a stop of some sort, and turn the engine SLOWLY by hand. i use a piece of a wire coat hangar. it'll rise as you turn the engine. as soon as it starts going down, back the engine up till it's up to its max. travel again.
 if you've done it right, your dist. rotor should be lined up directly on the #1 terminal of the cap, and the timing pointer on the crank should be at 0(TDC). if the dist. is pointed somewhere else, now you can move it. you may be off by a tooth.

 also, check where your vacuum advance is hooked up. you should be on ported vacuum, not manifold vacuum for this.
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Offline SFRT - Frenchy

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Re: Bad initial timing or intake leak?
« Reply #14 on: August 08, 2010, 08:07:31 PM »
New Edelbrock intake/4BB carb ... fixed  :rock

http://www.youtube.com/watch?v=9vT-ALqfAfQ&feature=channel 

On to bodywork once I find an aftermarket Kickdown bracket/cable.
Dat jugs bro.

Terror flieger since 1941.
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