Crate engine almost running - timing diagnosis?
Thread Starter
Race Director
Joined: Mar 2008
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From: coffee
Crate engine almost running - timing diagnosis?
I'm this (*holding fingers together, almost touching*) close to getting the crate engine in my '81 running. I have been able to get it to fire and run for a few seconds at a time by pumping the gas like a mad man and holding revs up a bit high (~2500 rpm, guessing, don't trust the tach at the moment), but it won't idle, and will sputter after a bit, backfire and die.
I installed my distributor using Lars' paper and I think I've got it close, but I was hoping there might be a troubleshooter's guide to getting it closer such that it will at least idle long enough for me to get a timing light on it. I don't want to just start twisting the distributor around *****-nilly, but I'm tempted.
Any ideas on next steps?
FYI - this is a standard HEI distributor, the CCC unit was malfunctioning and I have replaced both the carb and the distributor.
I installed my distributor using Lars' paper and I think I've got it close, but I was hoping there might be a troubleshooter's guide to getting it closer such that it will at least idle long enough for me to get a timing light on it. I don't want to just start twisting the distributor around *****-nilly, but I'm tempted.
Any ideas on next steps?
FYI - this is a standard HEI distributor, the CCC unit was malfunctioning and I have replaced both the carb and the distributor.
Last edited by nate99; Jun 20, 2011 at 08:55 AM.
Drifting
Joined: Feb 2005
Posts: 1,879
Likes: 38
From: Los Gatos CA
Bring #1 piston up towards tdc; stop anywhere between 6* and 10* before tdc. Turn key to on position and hook up timing light. Slowly rotate distributer. When light flashes lock down distributer. Prime carb and fire. Easy money.
Thread Starter
Race Director
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From: coffee
Heel & Toe
Joined: Jun 2011
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From: Clinton TN
How you gonna tell if you are on exhaust or firing stroke?
Thread Starter
Race Director
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From: coffee
Lars has a paper on finding TDC using a piston stop, which I did before installing the distributor the first time. Luckily, my balancer was close to spot on, but you never know until you check.
You can also pull the valve cover and watch the valves open and close as you turn the engine. If you watch the intake valve shut and then stay closed on #1 as you approach the TDC mark, you're there.
Easier to pop off the distributor cap at this point though.
You can also pull the valve cover and watch the valves open and close as you turn the engine. If you watch the intake valve shut and then stay closed on #1 as you approach the TDC mark, you're there.
Easier to pop off the distributor cap at this point though.
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Drifting
Joined: Feb 2005
Posts: 1,879
Likes: 38
From: Los Gatos CA
#1 compression check - Put your finger over the spark plug hole while clicking starter key... or pull valve cover and watch rockers...
Also - If she kicks and sputters you can be pretty sure you are 180* out. If you haven't experienced this, you need to install more distributers.
Also - If she kicks and sputters you can be pretty sure you are 180* out. If you haven't experienced this, you need to install more distributers.
Le Mans Master
Joined: Oct 2002
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From: Las Vegas - Just stop perpetuating myths please.
Carb or dizzy.
Well its hard to diagnose over the internet but if it timing it would have to be greatly retarded to backfire, sputter and die at idle. U can check this just by adding more initial timing - say 5 degrees and see if it improves or worsens.
As far as the carb it sounds like one of 3 things: either a large vacuum leak or needle/seat stuck open or stuck open float.
Vac leak check with starter fluid on the intake and carb and watch/listen for rpm increase.
Stuck open needle seat or float may need just to remove carb and give it a shake or open it up and have a look at float setting then watch your fuel pressure with a gauge to verify needle opens (lower fuel press) and closes/seats (increases fuel press).
Good luck nate,
cardo0
As far as the carb it sounds like one of 3 things: either a large vacuum leak or needle/seat stuck open or stuck open float.
Vac leak check with starter fluid on the intake and carb and watch/listen for rpm increase.
Stuck open needle seat or float may need just to remove carb and give it a shake or open it up and have a look at float setting then watch your fuel pressure with a gauge to verify needle opens (lower fuel press) and closes/seats (increases fuel press).
Good luck nate,
cardo0
Racer
Joined: Dec 2009
Posts: 415
Likes: 10
From: Richmond Va
I like that a lot. Never heard of this method, but makes a lot more sense than rotating motor, taking cap off to see rotor button, blah blah blah... I have dead timed about 5 motors and wish I had your technique when doing so. Thanks
Thread Starter
Race Director
Joined: Mar 2008
Posts: 15,161
Likes: 17
From: coffee
As far as the carb it sounds like one of 3 things: either a large vacuum leak or needle/seat stuck open or stuck open float.
Vac leak check with starter fluid on the intake and carb and watch/listen for rpm increase.
Stuck open needle seat or float may need just to remove carb and give it a shake or open it up and have a look at float setting then watch your fuel pressure with a gauge to verify needle opens (lower fuel press) and closes/seats (increases fuel press).
Good luck nate,
cardo0
Vac leak check with starter fluid on the intake and carb and watch/listen for rpm increase.
Stuck open needle seat or float may need just to remove carb and give it a shake or open it up and have a look at float setting then watch your fuel pressure with a gauge to verify needle opens (lower fuel press) and closes/seats (increases fuel press).
Good luck nate,
cardo0