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SBC Idle issue.

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Old 05-14-2017, 04:50 AM   #1
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Default SBC Idle issue.

Okay, so haven't posted here much but am having a issue getting my engine running so that I can get it timed. When i get my distributor set to just the right spot the car will fire. And starts idling. It then dies. Does not matter if I give it throttle or not checked for vac leaks and cant find anything that would be leaking. No pcv as engine did not have it when I got it. I have a video but Photobucket is being dumb, so I will post that later. I can adjust the timing a bit with the distributor with it running but have to keep redoing it as it does not run long enough to actually get it timed. Have all ports on intake manifold plugged. All ports on carb except fuel on side and break booster port on rear are plugged. Not sure if it makes a difference to anyone but the engine is in a RX7.

Parts:
SBC 350 (Out of I Believe a 69 El Camino)
Streetfire Ignition box.
Pro Comp Distibutor (No vac advance, non hei as I do not have room for it.)
Aftermarket summit racing return type FPR
Edelbrock 1406 600cfm carb
Some crappy block huggers that are currently open
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Old 05-18-2017, 07:57 AM   #2
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For the few minutes it runs, how does it run? Should also get some sort of even just scrap pipe and run some exhaust under the car, with shortys, just like manifolds there is still a chance of burning an exhaust valve.

Have you tried taking the street fire box out of the equation? I had one on my truck that go wet and would fire up for a moment then die. Also are you sure your distributor is working like it should? Pro-comp is not necessarily the best, and have been known to give fits, any chance you can borrow another one from someone and see if your car with start and run? When it dies can you tell if it just cuts itself out or is loosing spark and that's why it dies, and one last one, what coil are you running?
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Old 05-22-2017, 02:57 AM   #3
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Originally Posted by biketopia View Post
For the few minutes it runs, how does it run? Should also get some sort of even just scrap pipe and run some exhaust under the car, with shortys, just like manifolds there is still a chance of burning an exhaust valve.

Have you tried taking the street fire box out of the equation? I had one on my truck that go wet and would fire up for a moment then die. Also are you sure your distributor is working like it should? Pro-comp is not necessarily the best, and have been known to give fits, any chance you can borrow another one from someone and see if your car with start and run? When it dies can you tell if it just cuts itself out or is loosing spark and that's why it dies, and one last one, what coil are you running?
I have no other ignition solution currently than the street fire. not sure on the distributor but unless it was a lemon out of the box it should work fine, and I am getting spark. None of my friends have sbc's but ill see if there is anything i can dig up. I do have a HEI dizzy but it wont fit in the given space. Coil is a MSD blaster SS.


Also sorry the video is so shaky. The way it fades out and just dies, is what happens every time no matter what.

Last edited by DRFT_HRD; 05-22-2017 at 03:28 AM.
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Old 05-22-2017, 06:53 AM   #4
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Almost sounds like it's starving itself for fuel. Whats the fuel system like, is their rust in the tank, an old rubber line collapsing somewhere, what kinda fuel pump are you running? Just to rule out the box you should be able to just wire the distributor to the coil temporarily just to verify that isn't causing some kind of issue.
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Old 05-22-2017, 02:10 PM   #5
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Originally Posted by biketopia View Post
Almost sounds like it's starving itself for fuel. Whats the fuel system like, is their rust in the tank, an old rubber line collapsing somewhere, what kinda fuel pump are you running? Just to rule out the box you should be able to just wire the distributor to the coil temporarily just to verify that isn't causing some kind of issue.
System is a electric fuel pump to standard lines to return type fuel regulator to carb. No rust in the tank, pump and filter sock are clean too. Checked not long ago have been thinking about replacing the fuel lines and filter. Going to make some adjustments to the FPR and double check the return line and feed line are not crossed. Also will try running straight off the coil. Might not be until this weekend as I work a swing shift.
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Old 06-15-2017, 08:57 PM   #6
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So I tried running straight off the coil and am having the same issues also dialed in more fuel. So maybe it's just a bad distributor?
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Old 06-17-2017, 09:18 AM   #7
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1. Fuel pressure to the carburetor should be between 5-7 psi.

2. Don't reattach the StreetFire ignition box until you find out if the distributor is working correctly.

3. As a precaution, test your coil's resistance. (I've included a link not to insult your intelligence, but most guys in this day and age have never used a standalone coil.)

4. Manually set the initial timing to at least 12-14 degrees BTDC.

5. Make sure your distributor hold down clamp is tightened after setting initial timing. (The rotation of the Chevy rotor is clockwise and has a tendency to rotate the housing in that direction also thus retarding your timing.)

6. Put in a PCV valve and fresh air line in the other valve cover. (If you have marginal ring seal, combustion blow-by can choke out the engine as it has no where to go.)

Hope this helps. If fuel starvation is not the problem, I would suspect the electronic control module in the Pro Comp distributor is faulty and should be replaced.
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Old 06-17-2017, 08:03 PM   #8
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Re-reading your initial post, I was struck by the statement that "getting the distributor to the right spot" allows the engine to fire. There is a remote possibility that the cast iron outside ring has slipped on the elastomer binding it to the hub. A quick check for this condition is to hand crank the engine to TDC using a breaker bar on the harmonic balancer's retaining nut and see if the timing mark reads zero (or close to it +2 degrees since this is an approximation). Since the zero mark comes up twice (once for cylinder #1 and again for cylinder #6), remove the valve cover and watch the intake and exhaust valves for #1 cylinder. Zero valve movement is a good indication of TDC.

All the answers so far have been focusing on the ignition. Another item to check is the availability of fuel in the fuel bowl. After the engine dies, rotate the throttle level at least two times and note the strength and longevity of the accelerator pump shot. (The first rotation clears out any residual fuel while the second should match the first shot.) If the two shots aren't identical, fuel starvation may be the culprit.
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