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New 70 Duster barely starts, and backfires or spews soot
https://slantsix.org/forum/viewtopic.php?t=53793		 Page 2 of 6
Author:  pishta [ Fri Nov 08, 2013 3:34 pm ]
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I was going to say..."single pot?? how old is this 70 Duster???" Duals since 67. You can gravity bleed your brakes, crack farthest cylinder and let it drip into a cup, keep filling until it starts to drip clear, then move to 2nd farthest etc. Should expect to go through a whole bottle of brake fluid but since its available at the dollar store now, stock up. Dont let M/C go dry you dont want new bubbles in the line. MightyVac is a great tool to suction bleed brakes too with that little jar they give you.
Author:  killnine [ Fri Nov 08, 2013 8:09 pm ]
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Quote:
I was going to say..."single pot?? how old is this 70 Duster???" Duals since 67. You can gravity bleed your brakes, crack farthest cylinder and let it drip into a cup, keep filling until it starts to drip clear, then move to 2nd farthest etc. Should expect to go through a whole bottle of brake fluid but since its available at the dollar store now, stock up. Dont let M/C go dry you dont want new bubbles in the line. MightyVac is a great tool to suction bleed brakes too with that little jar they give you.
Yep, got a cardone new not rebuilt MC and put it on tonight after bench bleeding it. Hopefully the lines are good. I've got a mighty vac to do the cylinders with. I'll be going out tonight or early in the morning to get that done. I don't think I'm gonna risk the drive until I get the tires on and I can just drive it around the block a bit. I'm in a weird situation because I don't have another driveable car most days (the wife takes it to work for 12-14 hours a day until late at night). I'll just call my tow driver and maybe have him haul the wheels for me to get the new BFGs put on.

Anyone in the Tulsa area that wouldn't mind hanging out with another mopar guy? 8)
Author:  killnine [ Fri Nov 08, 2013 8:10 pm ]
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Exciting, isn't it, killnine? When they're up and running and the next few things seem pretty obvious (your tires, for instance) it's always a rush for me.

Are you replacing the old M/C with another single pot one? This would be an excellent time to do the dual master conversion.
Maybe you already know that the old style brakes will be completely gone if there's a hole anywhere in the system.
Engine running, etc. is all good, but you gotta STOP! It might even be good to have it towed home on the new tires. Or wait on the tires 'till you're sure of the brakes.
We don't wanna hear that you're switching to body & front end repairs now!! :oops: :roll:

BC
Exciting doesn't even cover it. My 68 Polara having been 17 hours away for the last 3 years, and only having it for a few weeks even back then, I really miss a mopar. I'm in heaven, even if there's lots of work to do.
Author:  killnine [ Fri Nov 08, 2013 8:13 pm ]
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Oh yeah I also need to get some suspension parts. All of the bushings and ball joints look like hell. I've done the poly thing before on my hondas and the Polara. Any recommendations? That and I think lower and upper ball joints. This work I'll have to farm out to a local shop. Too much for the apartment complex parking lot. Other than the tires the suspension will probably set me back the most in the wallet.
Author:  killnine [ Fri Nov 08, 2013 8:23 pm ]
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Author:  WagonsRcool [ Sat Nov 09, 2013 3:12 pm ]
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Now that you've got it running, you should consider adjusting the valves.
Author:  killnine [ Sat Nov 09, 2013 5:48 pm ]
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Well I got new BFGs today and put them on, so now when she does run I'll actually be safe doing so. I put the MC on last night and bled the brakes, but doing it by myself with the mityvac didn't work as well as I thought it would. It seemed to be sucking more air than it should, so I couldn't tell at all if it was bled or not in the front. I didn't do anything to the rear because the bleed fittings were some other size I didn't have an offset bleeder wrench for. Anyone know what size these are?

I put the CH-410X dizzy cap and Echlin MO-3000 on it today, and then started her up again. It was definitely harder to get going. I had to give it a lot of gas to get it to fire. Maybe the temperature had some effect. It was colder today then before. Once I got it running it wasn't too bad, but back to wanting to stutter if I give it a quick pedal hit. If I hit the pedal slowly, it doesn't seem bad. No backfiring at least. If anything, it smells rich, but it's harder to tell now. Maybe there's something going on with the cap and rotor, but I doubt it. I have a lot of carb work to do I think. I was hoping to avoid taking it off the car but I think I'm in for a full rebuild.

Once I got it running, I tried to test the brakes, but I got pedal to the floor, and when I did push the pedal, it starts to stutter oddly at idle, like the power booster for the brakes is causing some kind of issue, or maybe it being to the floor causes that.

Oh well, I have nice tires :)
Author:  pishta [ Sat Nov 09, 2013 8:12 pm ]
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remove the power brake hose, I bet your PB hose fitting is bad. Adjust valves after you get it hot. see if that helps anything. Also disconnect your choke for the hot start. Would a 2180 Holley fit that BBD kickdown setup?
Author:  killnine [ Sat Nov 09, 2013 9:20 pm ]
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remove the power brake hose, I bet your PB hose fitting is bad. Adjust valves after you get it hot. see if that helps anything. Also disconnect your choke for the hot start. Would a 2180 Holley fit that BBD kickdown setup?
Yeah I will check that fitting. The brakes gave them a lot of trouble, I wouldn't be surprised if it was crudded up or something.

I'm pretty sure my start and idle issues are accelerator pump issues. I need to check the float and make any necessary adjustments. I sure wish I didn't have to disconnect all of the lnikages to break this open.

One important clue that I'm not sure I mentioned. When it started, it would start well, then come down and want to die. So I got it warmed up by giving it steady pedal. I turned the fast idle up a little to combat that.
Author:  killnine [ Sun Nov 10, 2013 3:03 pm ]
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Replaced the booster hose and the rubber nipple, as both seemed a little leaky. The valve holds one way and not the other with mouth pressure. PEdal still goes to the floor but I haven't bled the whole system yet. I still get a worse idle when I let the pedal go all the way down. I'm not really forcing it.

A little more general info. When it's warmed up, the timing light shows it at 0 +/- around 3, mostly BDC, sometimes ADC. It seems to bounce a bit.

A vacuum gauge on the extra fitting where the booster connects at the manifold reads around 12 Hg at warmed up idle. It's fairly steady vacuum, maybe a +/- 1 fluctuation.
Author:  killnine [ Sun Nov 10, 2013 4:06 pm ]
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I sprayed carb cleaner everywhere I could think of around the carb and intake, and I didn't notice much fluctuation. I think the 12 Hg vacuum is perhaps just a side effect of the current purple stick. It lopes around 12 at idle, drops then rises at acceleration, and rises at deceleration. Looking at the dizzy, it seems to be retarded as far as the PO could get the bracket to turn. Would that be normal at around 0 timing?
Author:  killnine [ Mon Nov 11, 2013 9:58 am ]
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Well, I think I scared everyone away, but I did take apart the carb, reset everything to spec for this specific carb model, including the pump, the metering rod, and the float. Replaced some of the gaskets from my kit, and kept the accel pump as it seemed like the one already in there was better quality (a green diaphragm if it matters). I didn't replace the jets as they were in really tight and I don't have a proper driver. Put it back together, did everything by the book, started it up, prayed, adjusted the high idle a bit, let it warm up, blipped the throttle, let it settle, adjusted the curb idle a bit, and let it warm up some more. I capped off the vacuum advance at the carb and watched the vacuum at around 14 tops. I had set the mixture screws about 3 turns out, and so I tried adjusting them in a bit, but it started acting a little odd, and the vacuum didn't change much, so I set it back. I can usually get a good throttle response, maybe just a little hesitation. I can't put it in drive with brakes since I haven't fixed the brakes yet. If it isn't exactly right it seems to want to backfire when I hit the pedal quickly. Everything is peaches if I don't though, but it still smells rich. When I do hit the throttle fast I'm seeing a little greyish white exhaust.
Author:  Reed [ Mon Nov 11, 2013 10:27 am ]
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I think I see part your your idle mixture problem. On the side of the carb close to the firewall you have a red vacuum cap over a nipple towards the top of the carb. This nipple is on the idle air enrichment valve. This was a feature that did exactly as its name implies- it richens the idle mixture based on the vacuum signal provided to the valve. Yours is capped off so it isn't working.

On pages 5-6 of THIS BBD manual, it indicates that carbs equipped with this idle air enrichment valve have the valve tied into the EGR valve and an electronic timer. You may wish to find a different carburetor than that one to put on your car.
Author:  killnine [ Mon Nov 11, 2013 12:29 pm ]
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I think I see part your your idle mixture problem. On the side of the carb close to the firewall you have a red vacuum cap over a nipple towards the top of the carb. This nipple is on the idle air enrichment valve. This was a feature that did exactly as its name implies- it richens the idle mixture based on the vacuum signal provided to the valve. Yours is capped off so it isn't working.

On pages 5-6 of THIS BBD manual, it indicates that carbs equipped with this idle air enrichment valve have the valve tied into the EGR valve and an electronic timer. You may wish to find a different carburetor than that one to put on your car.
That is indeed questionable. Given what I'm reading though it seems like it could cause issues initially, but that it shouldn't really affect it once it's warmed up, since it would normally kick off vacuum to it once warm anyhow. Definitely something to consider though, especially for the initial starting mixture.
Author:  killnine [ Mon Nov 11, 2013 5:08 pm ]
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Well, no matter what I do the vacuum advance fitting on the carb provides vacuum, despite supposedly being ported. If I adjust the curb idle any lower it will die, and it will be a completely closed throttle. It's the same amount of vacuum as non-ported. so something is definitely very wrong. Considering I just went through most of the top end of the carb, and carb spray around everything doesn't show any leaks, I guess maybe it's something in the bottom end of the carb?
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