Reed,
What was that thingie called again?
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| Emissions parts question - new member https://www.slantsix.org/forum/viewtopic.php?t=49255 |
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| Author: | Reed [ Thu Jul 12, 2012 12:08 am ] |
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The smurf connected to the smurf... |
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| Author: | emsvitil [ Thu Jul 12, 2012 12:24 am ] |
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Reed, What was that thingie called again?
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| Author: | dc [ Thu Jul 12, 2012 3:13 am ] |
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I'll look for the choked jerkybat plugs. So any ideas on what type of carb that is? Would you recommend changing it out for a more correct one that has the idle stop solenoid? Also, reed, I bought a reman'd airpump, but I do need the brackets and tubes and everything else (and the relief/diverter valve). I did read the post about doing a custom setup, but if I can find the right stuff that matches the haynes/chiltons manual, I think I'll have an easier time getting it to work. Also, I read if you run air without the diverter/relief valve, it can mess up the ca at higher rpms (too much air), or cause backfire. |
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| Author: | Reed [ Thu Jul 12, 2012 7:43 am ] |
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I'll look for the brackets this weekend. I can't guarantee that I have them, though. Don't use a Haynes or Chilton's manual. They are full of errors and misinformation. When you get into technical stuff like setting up a air injection system, you absolutely need to have the factory service manual for your year and model of vehicle. HERE is one for $13 plus $5 shipping. Can't beat that with a stick. Your carb appears to be a Holley 1945, which is likely the correct carb for your 1985 truck. The main issue is that your emissions sticker clearly indicates that your truck has or originally had a lean-burn computer. I don't see the provision on the carb for the computer to control the carb, so the computer controlled your ignition system. I don't know if the computer is still there or what ignition system you are running now, but if the computer has been removed and a conventional electronic ignition system installed in its place, you need to make sure that the distributor is getting a ported vacuum signal to the vacuum advance pod (ported means little to no vacuum at idle, but full manifold vacuum as soon as the throttle is opened). Given that the rest of the emissions related equipment has ben removed, I suspect that a previous owner of the truck probably removed the leanburn system and hacked up the wiring harness. Hopefully the previous owner correctly installed functioning ignition system. I would go over the remaining wiring harness in your engine bay and verify whether or not you have a plug that matches the plug for the idle stop solenoid. There will be only one plug that matches the shape of the ISS plug. If your truck has A/C, you definitely want the idle stop solenoid to be functional. As far as diverter valves and upstream and downstream air injection, I really don't have an intelligent answer. I am not familiar enough with the finer points of how the catalytic and air injection systems work to tell you how to set it up. According to my 1983 Dodge van factory service manual, the "upstream" injection point is the port at the back of the cylinder head. Air is injected there only during warmup. Once the motor warms up, air is injected directly into the catalytics for best possible operation. This is why I set the system up on my brother's van as a downstream injection only system. No need for all the hoses and solenoids controlling a switching valve. When no vacuum is applied to the switching valve, the valve send air to the downstream location. This is why I got away with installing the air pump without any of the controlling hardware for the switching valve. The diverter and relief valve function to keep pressures in the air injection system from becoming too great. Fortunately, these are built into the connector that attaches the hose to the pump. If you are going to install an air pump and catalytic converter, I would keep it simple and set it up like I did- downstream injection only with none of the switching valve control hardware. The only thing you loose would be the upstream air injection which only functions during cold startup anyway. The problem will be getting the carb to play nice with the catalytic. Most non-computer controlled carbs didn't have precise enough fuel mixture control to play well with a catalytic converter. The end result is what happened to my brother's van- converter meltdown:  Also, I see you have a hard plastic vacuum line dangling back behind the #6 cylinder. I suspect that that is the vacuum supply line for the HVAC controls and vent doors. If your heater and vents don't work, try hooking that hose back up and see if they do work. |
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| Author: | dc [ Thu Jul 12, 2012 5:04 pm ] |
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Thanks! I ordered the manual. Also, my truck does not have A/C. I'm leaning towards not messing with the cats since the truck seems to run pretty well. I'll check on the carb and ignition though to try and find out what the PO did. |
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| Author: | Ed Mullen [ Sun Jul 15, 2012 6:06 pm ] |
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If you are keeping the truck lean burn, I have a low miles rebuilt carb (rebuilt by me w/NAPA kit) you could have for cost of shipping. I had an earlier carb rebuilt from a core at the nearby carb shop. They didn't charge a core deposit and asked that I return "any 1bbl" when I have the chance. I swapped it because I needed a vac-advance port for HEI and because the idle stop solenoid was shot (making idle adjustment 'interesting'). If you bolt a good solenoid on it, it should be fine for many miles. (even if you don't wire it up, the solenoid is where the curb idle is adjusted on those.) (I need to check my garage to see if I have enough parts to make a core to return to the shop.) |
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| Author: | dc [ Sun Jul 22, 2012 5:11 pm ] |
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I dont know if I have the lean burn computer on my truck still installed, but I would be interested in the carb in the event that I'm able to put it back to stock. I appreciate the offer! Would you PM me the information on how much shipping would be to 27591? |
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| Author: | dc [ Mon Jul 30, 2012 11:32 am ] |
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Ok, I have an additional question about adding a catalytic converter. I've read several of Dan's posts by using the search function, and found a few parts he recommended. Basically for my truck I would need a big cat with air injection port for my new air pump parts that Reed is being kind enough to sell me. Will this do the trick? http://shop.advanceautoparts.com/webapp ... fragment-2 I'm guessing due to the low price that it doesn't have a ton of platinum in it... but it is pretty darn big, and comes up as a "direct fit" for my slant six truck. At 17.75" long, I'm thinking it should do the trick with less chance of overheating. Thoughts? |
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| Author: | SlantSixDan [ Mon Jul 30, 2012 11:49 am ] |
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Never had much luck with Magnaflow's exhaust products (durability fail). You need a heavy catalyst load to cope with the dirty exhaust from a truck like yours. Scrimping will only mean quick catalytic converter failure and a need to do the job again (and again and again until you buy a converter robust enough to do the job you're asking of it). Get a Catco #512006. I've seen it for as little as $70 and as much as $170. No experience with "Max Auto", the place I found on Google selling it for $70, so no idea if that's a screamin' deal or a counterfeit part or what. Summit has it for $117, see here. Install this converter in the stock location. Wrap the headpipe (from manifold outlet to catalyst input) with thermal insulating wrap, such as this, to get the converter up to temperature in a hurry and keep it there, thus greatly reducing raw-fuel loading in the catalyst. Voila, clean unrestricted exhaust. If you need a muffler, pick a nice big quiet free-flowing Walker #50051. |
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| Author: | Reed [ Mon Jul 30, 2012 11:51 am ] |
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That looks almost identical to the one I installed on my brother's 83 Dodge van. Mine was marketed by "CatCo" and cost about $100. Be aware that it only lasted a few months before melting down. This might have ben because the van was running a non-computer controlled carb. The converter was also installed well behind the stock location. |
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| Author: | SlantSixDan [ Mon Jul 30, 2012 12:07 pm ] |
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Reed's example nicely illustrates why the catalytic converter must be selected by what's inside it, not by how big it is on the outside. All converter suppliers produce a range of converters. Using one inadequate for the task results in early meltdown and wasted money. |
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| Author: | dc [ Mon Jul 30, 2012 12:17 pm ] |
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I'll grab the catco. I saw that one in another one of your posts, but didn't know how to determine which ones have sufficient substrate materials or not. My truck currently runs rich and is a bit hard to start, so I might hold off on putting in the cat until I get that rectified. |
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| Author: | SlantSixDan [ Mon Jul 30, 2012 1:28 pm ] |
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Yup. Nothing cooks a cat (meow!) faster than overly-rich exhaust. |
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