Fresh rebuild, won't start?

Pull all the plugs and spin any excess fuel out. Pull the passenger side valve cover and dead time the engine, Check to make sure your timing mark coincides with the #1 intake valve closing set the balancer at 10* advanced and set the distributors to point directly at number one plug wire. Reinstall plugs Charge battery to full capacity and pump gas twice. Then crank for about ten seconds if no start pump gas twice more and hold throttle about quarter way open then crank. This should get her fired or atleast trying to if she tries to fire you may need to give it a little more gas to get it to start first time. If it won't start with three shots of throttle I would start trying to figure out why.

Does it have any spark?

dkp

bosshoss said:

Does it have any spark?

dkp

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Sounds like a no spark condition, ck your dizzy.

Good news...........Thanks to bigblok86ranger, it now starts!

Bad news............it won't idile on its own and the longest I could manage to keep it running was around 30 seconds, and that is with me pumping the gas pedal. I'm not sure if it's getting too much gas or not enough.

I hope it doesn't have anything to do with the petro. I'm running 93 octane gas. My C/R should be in the neighborhood of 9.5 to 10:1. The cam is a Comp X4270H, and my carb is a Holley 870 Street Avenger.

I've adjusted the timing, and adjusted and adjusted. Finally set it where it seems to start and run the best.

If anyone has any ideas, please let me know. Thanks.........

If it's popping through the carb, give it more timing advance. If it runs above 1500RPM or so but not below, it might be a vacuum leak of some kind. Mine did something similar this year, it just refused to stay running. Yeah, I was out of gas. Try more advance, and maybe known good carb.

Is this a new build that needs a cam breakin done? I hope not.

tall69 said:

If it's popping through the carb, give it more timing advance. If it runs above 1500RPM or so but not below, it might be a vacuum leak of some kind. Mine did something similar this year, it just refused to stay running. Yeah, I was out of gas. Try more advance, and maybe known good carb.

Is this a new build that needs a cam breakin done? I hope not.

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Yes it is a new build that needs a cam breakin. It's not poppin thru the carb. It just won't idile or stay running.

Dumb question: Which way do I turn the distributor to advance timing, clockwise or counter? Dumber question: What do I connect the vaccum line to that comes from the distrbutor?

Clockwise. The vacuum advance is attached at one of the vacuum taps on the body of the carburetor. Any that arent in use, should be capped or you will have vacuum leaks.

Wayne

Pull the sight plugs on the carb and make sure floats are set correctly kinda sounds like they may be TOO low. You just want gas to trickle out with the fuel pump on.

*** UPDATE ***
I've set the floats, sealed the vaccum leaks, insured it is getting spark and fuel. It starts up with no problem, but only runs for a few seconds. Any other suggestions?

Could the problem be the fuel pump not supplying enough fuel after the initial start? The fuel pump flows a little over 1 pint in 20 seconds, which is the flow rate for a standard volumn fuel pump.

Fuel filter?
New or used carb?
If used, is it SPOTLESS clean inside (jets, ports, air bleeds, etc.?)
Replace carb with another KNOWN GOOD one.

Still sounds like fuel delivery problem. A full fuel bowl should run for more than just a few seconds by itself with no refill.

You are out of time with cam break in lube doing any good...

tvolsr1 said:

*** UPDATE ***
I've set the floats, sealed the vaccum leaks, insured it is getting spark and fuel. It starts up with no problem, but only runs for a few seconds. Any other suggestions?

Could the problem be the fuel pump not supplying enough fuel after the initial start? The fuel pump flows a little over 1 pint in 20 seconds, which is the flow rate for a standard volumn fuel pump.

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That's in line with a standard replacement style mechanical pump (27GPH). It should be enough to supply it at least during the idle portion of the break in. Does it die hard, or sputter to a stop? Is it fuel or ignition? Have you tried a different carb?

BTW, you're getting into some scary territory with this going on when you've got a fresh cam to break in. You might want to put some more moly paste on the lifter bases or something.

It's got a new fuel filter, clear, so I know it is getting fuel. NEW carb, Holley 870 street avenger.

How is the battery dooing while you are going through all this? What ignition do you have? MSD ignition is very power hungry and if voltage drops below ~10 volts the engine will die. I would have the alternator and battery tested. If both test good then it has too be the carb or fuel related. The things that you have done to the carb... have helped from what you say but it could be a combination of them and a bad battery/alternator that are causing you problems. To avoid this I always have another vehicle "jumping" the vehicle I am starting for first time. Good luck and let us know please.

tvolsr1 said:

It's got a new fuel filter, clear, so I know it is getting fuel. NEW carb, Holley 870 street avenger.

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Was the carb sealed in a plastic bag of just sitting in styrofoam? I have had problems with "new" carbs that caused absolute fits and upon finally tearing into them you would be surprised the places little chunks of that crap will get into.

*** PROBLEM SOLVED! ***

I finally had it towed to my machanic. He tested the fuel pressure and found it to only be 3psi. We are installing a mechanical fuel pump, set at 9psi, to boost the fuel pressure. The rate of fuel it was flowing was fine, the psi was just too low after going from the stock carb to an 870 cfm.