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| Possible Ignition issue https://slantsix.org/forum/viewtopic.php?t=67433 |
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| Author: | Thebearded1 [ Wed Sep 27, 2023 2:51 pm ] |
| Post subject: | Possible Ignition issue |
I have a 225 slant six in my hot rod roadster. It's a 72 stock except for a super six intake and Stromberg ww3 carb. The ballast resistor the previous owner had in the car broke, it was a curved ceramic one not sure what application. I purchased one for a 72 slant six dart with the 2 hookups. One wire comes from my ignition and the other goes to the coil. I am using a GM one wire alt so it has an internal voltage regulator. I have a stumble or misfire around 1500 rpm when I rev it there in park. Points dwell is 43 and timing is set at 6 btdc. This is as far as I can adjust the timing using both adjustment bolts. When I measure across the ballast resistor with nothing hooked up I'm getting 1.7 ohms. With the ignition on I'm getting 12 volts in and 6.8 volts out. Running I'm getting 14.6 volts in and 10.6 volts to the coil. Are these voltage numbers in line with what would be expected? If so what else could be causing this stumble? Air mixture screws are set and I'm getting 18 hg at 750 rpm. I recently set the valve lash while.tunning and made sure not to mix up the exhaust and intake. Plugs are the recommended ngks and are gapped correctly. They are all uniform light brown in color. I run 89 non ethanol fuel. I also checked for vacuum leaks around the carb and intake runners. I used Remflex.gaskets |
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| Author: | slantzilla [ Wed Sep 27, 2023 6:18 pm ] |
| Post subject: | Re: Possible Ignition issue |
Vacuum advance hooked up? What is your total mechanical advance? 6 BTDC seems a little slow, I'd move the distributor a tooth and start the adjustment process again. Is the coil supposed to be used with a resistor? |
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| Author: | Thebearded1 [ Thu Sep 28, 2023 4:49 am ] |
| Post subject: | Re: Possible Ignition issue |
Quote: Vacuum advance hooked up? What is your total mechanical advance? 6 BTDC seems a little slow, I'd move the distributor a tooth and start the adjustment process again.
Yup the vac advanced is hooked up to ported vacuum. And the advancer does work when I put vacuum on the hose. Not sure how much mechanical advance I'm getting since I don't have a dial back timing light. I guess I could put some timing tape on the balance to see. I might be able to check that this evening. I did check the timing mark on the balancer with a piston stop as well.Is the coil supposed to be used with a resistor? I saw people suggesting 10 btdc but I couldn't get there. I will try moving it a tooth this evening. I need to go a tooth back so turn the rotor counterclockwise right? It looks like a stock coil to me. I thought all points ignitions used a resistor to prolong the life of the points. |
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| Author: | Thebearded1 [ Fri Sep 29, 2023 6:39 am ] |
| Post subject: | Re: Possible Ignition issue |
I moved the distributor 1 tooth and set the initial timing at 10 btdc. I also tried a little more but no change the miss is still there. Didn't find my timing tapes so I wasn't able to check total mechanical timing. |
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| Author: | Greg Ondayko [ Fri Sep 29, 2023 10:14 am ] |
| Post subject: | Re: Possible Ignition issue |
I might suggest getting rid of all of that stuff and either going with the HEI Ignition as listed here on the forum or of you want to keep the points distributor getting a pertronix setup to replace the points / coil and eliminate the ballast resistor in the process. If that misfire is still there after swapping to a different system then it is something else mechanical related. Greg |
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| Author: | volaredon [ Fri Sep 29, 2023 7:19 pm ] |
| Post subject: | Re: Possible Ignition issue |
Though I have yet to convert one to hei, (I have a 318 lean burn car in mind as a guinea pig when I delete the LB) But I have had good luck with the regular 4 pin Mopar electronic ignition system and have converted several to that over the years. "Don't fix what ain't broke" it works for me. Your luck might vary |
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| Author: | Thebearded1 [ Tue Oct 03, 2023 5:45 pm ] |
| Post subject: | Re: Possible Ignition issue |
i've thought about the hei conversion but haven't wanted to track down the distributor. While drag racing this weekend the car was stalling when launching. It's a 904 and I was letting the revs get up to 1000 while holding the brake. When I left the choke pulled out a little it helped prevent the stalling. Maybe i need to go up a jet size? |
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| Author: | slantzilla [ Tue Oct 03, 2023 6:56 pm ] |
| Post subject: | Re: Possible Ignition issue |
What carb do you have? |
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| Author: | Rick Covalt [ Wed Oct 04, 2023 3:07 am ] |
| Post subject: | Re: Possible Ignition issue |
Quote: letting the revs get up to 1000 while holding the brake.
1000 is not that much above idle. What happens at 1500 or 2000? It may be the accelerator pump shot is not large enough or is too large for the rpm you are starting at.
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| Author: | Greg Ondayko [ Wed Oct 04, 2023 6:44 am ] |
| Post subject: | Re: Possible Ignition issue |
Do you have an AFR Gauge installed in the exhaust? That can help provide you with some more informed data points that can drive your decision-making process here. You might be onto something with the choke observation. As others have asked, what carbby is slapped on top of that Hot Rod?  Greg |
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| Author: | wjajr [ Wed Oct 04, 2023 9:06 am ] |
| Post subject: | Re: Possible Ignition issue |
First sentence in the first post: I have a 225 slant six in my hot rod roadster. It's a 72 stock except for a super six intake and Stromberg ww3 carb. |
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| Author: | Greg Ondayko [ Wed Oct 04, 2023 1:07 pm ] |
| Post subject: | Re: Possible Ignition issue |
Thanks, I cannot offer anything about the tunability of a stromberg ww3. Greg |
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| Author: | Thebearded1 [ Wed Oct 04, 2023 4:30 pm ] |
| Post subject: | Re: Possible Ignition issue |
Quote: What carb do you have?
Stromberg WW3
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| Author: | Thebearded1 [ Wed Oct 04, 2023 4:32 pm ] |
| Post subject: | Re: Possible Ignition issue |
Quote: Quote: letting the revs get up to 1000 while holding the brake.
1000 is not that much above idle. What happens at 1500 or 2000? It may be the accelerator pump shot is not large enough or is too large for the rpm you are starting at. |
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