AMC Eagle Den Forum
The Mighty 258 => Emissions/Vacuum Systems => Topic started by: olymunch on April 19, 2012, 04:37:31 AM
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Does anyone know what emission stuff can be removed in order to improve HP and fuel economy?
I've heard of people blocking off the egr and removing the cat on their non Amc cars and getting better performance.
I'm installing a crate 258 and upgrading to the 4.0 and mpi so if I can also get rid of all the crud that restricts my engine that would be great. I'm smog exempt.
Thanks
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I'm planning for this on my 4.2L in the near future. If you have an air pump, that can go along with the air injection manifold and the hoses and vaccum diverter valves. It also has a hose that goes into the cat converter and you can either remove the cat altogether or just plug the air line going to it.
The EGR and CTO can go along with a half a mile of vac lines. Then you can remove the A/C compressor and move the alternator up if you want too. I don't really care to have A/C so I will remove mine at some point at least on the engine side of things. I may just block off the lines going to the condenser since it is under the dash and a lot of work to remove.
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Thanks that's what I'm looking for!
Anyone have any success with these kinds of mods?
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Just keep in mind that removal of your cat here in WA can result in a $5,000 fine from the EPA if you're caught. Mine is going to a high flow cat (for what I can get for my old one for scrap, I can afford a new one)
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When all the emission controls are functioning properly, removing it will not really help your horsepower or fuel efficiency. The only one that actually uses engine power is the air pump (if you have one), and that load is quite negligible.
That said, most of them can be removed.
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Ammachine390, yea but that's a big IF. I'd rather just take off all those vacuum lines. I love my eagle but man does the engine compartment look cluttered. So if I can un-clutter it and raise the performance and eliminate the headache of emission control things then I'm all in.
Carnuck, I'm pretty sure 30 year old cars in WA state are exempt from smog regulations, plus how would anyone ever find out. But still 5k? Thanks for the heads up
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Technically its a federal thing with fines to remove a cat.
mine are currently being replaced due to theft iirc. might have forgot who took them and might have forgot when. couldn't remember but thought i replaced it. sorry will get right on that.
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Don't forget about the savings in weight. With all the extra "stuff" you will probably save 40-50lbs of weight up front.
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I don't think that removing the emissions control equipment will result in a big horsepower improvement. I think it might run better (less stalling, hesitation, etc) but I doubt you'll see a real difference in acceleration or top end speed.
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Maybe, but any gain would be worth it. Especially just aestheticly, I really like a clean engine compartment but almost every one I've ever seen looks like a rats nest, even very well taken care of ones.
Does anyone have any experience with this kind of job?
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I will soon! Maybe we should compare notes. I plan to start on it this weekend.
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I still have my catalytic converter, and my EGR, CTO, and smog pump are still in place. However, I removed the belt from the smog pump, and I don't have the vacuum lines hooked to the EGR or the CTO, and I removed the stuff that was on the top of the valve cover. I also switched to the Gronk's Motorcraft carb, and my car runs great now. As I said, not much improvement on performance, but it runs better.
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I would also think that removing most items won't make a difference, except for an air pump or an old pellet-type catalytic converter. Monolithic converters on a stock engine just wouldn't be enough of a restriction.
While articles on cars seem to all state that emissions devices robbed power, the numbers for the 258 are pretty consistent and the last 258s got higher compression and slightly better (though still poor) cams. In '72, right in the middle of adding emissions devices ratings went from gross to net so the same engine with no changes whatsoever from 71 to 72 lost 1/4 to 1/3 of it's "horsepower". According to a Chilton's I have handy in '75 the 258 made 110 hp and in '87 it made 112.
That said, if you're putting the Mopar MPI system on it (as opposed to the Renix) there's very little emissions equipment as a part of it. Only the cat is notable, and at least some versions throw a code if it's not working so you might need it to pass inspection depending on your local regulations.
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I think the biggest gain is not intended to be HP but less stuff to break. I don't expect more power at all. I just want to minimize the stuff in the way.
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Ya that's %90 of it for me as well, my egr went bad in my truck and it took me a while to figure it out because it was staying open creating a vacuum leak. After much diagnostics, it only happened at high speeds under load, I found it and replaced it. The only reason I didn't block it was because the block kit was about the same price and not available that day and I was just tired of dealing with it. And of course a cleaner looking engine bay.
So I've got the 81 sx4 that was switched from an automatic to a 5speed. Is there any way to tell if I have the air pump or a diagram showing where everything that I can take off is?
Rohnk, when you do yours can you take pics if its not to much trouble? It would be a great write up!
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Ammachine390, yea but that's a big IF. I'd rather just take off all those vacuum lines. I love my eagle but man does the engine compartment look cluttered. So if I can un-clutter it and raise the performance and eliminate the headache of emission control things then I'm all in.
Carnuck, I'm pretty sure 30 year old cars in WA state are exempt from smog regulations, plus how would anyone ever find out. But still 5k? Thanks for the heads up
Its easy to see no cat if you look under a rig, plus it is a federal thing, if your car came with one then technology it has to have one. and remember any policeman that knows will turn you in to the EPA. also the EPA does not care about you, they only care about the environment they WILL fine you. besides always run a cat people around you will thank you. when i go wheeling if your "that guy" and your not running a cat then it's back of the line. properly tuned engine or not the cat eliminates some hardcore fumes. Like carnuck said get a high flow one. I say if you research what the systems do most are good and dont rob power, most are there to help the engine as well as cut back on emissions. Im running, egr, pcv, and a cat, you can get rid of a ton of vac and computer stuff if you have it. the only other thing would be gonks carb kit, i need one too. you can get power, save fuel, and not have your eyes water every time you are sitting at a stop light.it win win.
my clutter is in wires not emissions i think i have like 3 vac lines
(http://i604.photobucket.com/albums/tt128/Standup650/IMG_0376.jpg)
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Ya that's %90 of it for me as well, my egr went bad in my truck and it took me a while to figure it out because it was staying open creating a vacuum leak. After much diagnostics, it only happened at high speeds under load, I found it and replaced it. The only reason I didn't block it was because the block kit was about the same price and not available that day and I was just tired of dealing with it. And of course a cleaner looking engine bay.
So I've got the 81 sx4 that was switched from an automatic to a 5speed. Is there any way to tell if I have the air pump or a diagram showing where everything that I can take off is?
Rohnk, when you do yours can you take pics if its not to much trouble? It would be a great write up!
Yes, I'll take some pictures. I also printed off the digram from Eaglepedia that shows all the vac line routing and smog stuff. I highlighted everything in red that can come off the engine. I'll take a pic tonight so you have an idea of what your going to be getting into. Maybe I'll start a thread on the subject as well.
Also, like standup650 says, you should keep the catalytic converter in the system. They do remove a lot of crud from the air. All I will do with my cat is remove the line from it to the air pump and cap it off. The cat will stay in the system though.
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Once I get some time, I'll be yanking that stuff out of mine. Main thing is do NOT pull the air pump before pulling the cat (unless you're not driving it) The old cats will superheat and set your floor on fire if they aren't getting enough air into them.
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Ya those are all good points. After looking up how the old cats differ from the new ones I'll prob spend the money and get a new one for higher flow. Also good to know about the line going to the cat. I know they only really work when hot but had no idea they were temp regulated to keep from overheating.
Looking forward to the diagram and pics, that'll be a HUGE help!
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Once I get some time, I'll be yanking that stuff out of mine. Main thing is do NOT pull the air pump before pulling the cat (unless you're not driving it) The old cats will superheat and set your floor on fire if they aren't getting enough air into them.
Oh snap! I totally didn't think of this. Dang it. Well, I guess I should plan to get a new MagnaFlow then. I looked one up on the O'Reilly site and the picture shows a MagnaFlow with a tube on the side for the air injection. There is also a universal fit one that doesn't have that tube.
Now what do I do!? :banghead:
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I was just reading the TSM and it says that all 6 cyl engines use the same type of air pump. How can that be when I have seen many pictures of engines on the forum that don't have an air pump? I'm confused by this.
If your car doesn't have an air pump, then what keeps the catalytic cool? All the replacement cats that I have looked up have an air tube on them. I was mistaken earlier about the universal fits, they have the air tube also.
Does anybody have a converter with an air tube that is blocked off?
Now I am considering removing the cat altogether but I really dont want to do that. I'm a borderline tree hugger and I like the environment so I'd really like to run the converter if possible. Just don't want it melting down or starting a fire.
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Ok, sorry for taking over this thread. I looked in the Eaglepedia under the diagram section for exhaust and chose the 6 cyl. It shows the exhaust system with airtube in the main diagram. In the smaller diagrams below the main one, it states that you can plug the air tube with a 3/8" pipe fitting.
So apparently, the air injection is not needed to help cool the converter, just to help it burn the gases more efficiently on smog equipment built vehicles. On non-smog vehicles, they must have used the same converter but plugged the air tube on it since there is no air pump to inject air.
Sound right to anybody else? I just want to do what is right here for the sake of my Eagle and the enviroment.
BTW, Magnaflow cats from O'Reilly's are $67. Not a huge amount of money I guess and it should perform better than the stock one that is on there now.
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I had to put a new cat on my car since it was cut off when I bought it. I bought it off the auction site from some place in Lansing. It does not have a feed from the air pump. The air pump on my 81 goes to a manifold that taps into the exhaust manifold. I have been running it for almost 3 years without the air pump being functional with no problems.
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Right, there is a single feed air injection and a dual feed air injection. The single feed only pushes air into the exhaust manifold via the air injection manifold. The dual feed pushes air into the injection manifold and catalytic converter through a diverter valve and vacuum control switch. The valve is controlled by vacuum from the CTO. As the engine gets warm, the CTO opens ported vacuum to the air control valve which starts air flowing to the catalytic convert.
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The air pump was last used on Eagles in 1982. 1980 and 81 (except California Models) models are equipped with a single air injection, which feeds only to the exhaust manifold. In 1982, Eagles got computer controls. The ECM controls the the air valve operation. When the engine is cold, air is directed to the exhaust manifold since a cold engine runs rich, so this cleans it up, and it heats up the O2 sensor faster. Once the engine warms up, the computer switches off the vacuum solenoid, and the air is directed to the catalytic converter.
You should be ok disconnecting the air pump tube to the catalytic converter.
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My '81 has the plastic valve cover, non-feedback carb, dual AIR injection (manifold and cat) because it was a CA car. I drove it home from the shop tonight (just a couple miles) and it stunk of oil leak. In the AM I will be loading tools, power inverter, sawzall, air compressor and other stuff in the wagon and going to my cabin to disassemble the XJ parts rig of my buddy's plus cut the cab off the datsun pickup that's becoming a trailer.
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My '81 has the plastic valve cover, non-feedback carb, dual AIR injection (manifold and cat) because it was a CA car.
Being a California model, it should have the dual air injection as well as the feedback carb. Maybe someone switched the carb? The feedback system used on the 81 California Eagles was the same that all 81 Concords and Spirits have. They are not like the usual Eagle feedback system, as it is the only feedback system that does not control the ignition timing in any way, all it does control is the air injection solenoids, and the stepper motor.
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The little TPS switch on the back? There doesn't appear to be any harness for the feedback carb yet it has TONS of extraneous hoses that will disappear soon (after I swap in a new cat)
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If it is a feedback carb, there is a stepper motor on the back side of the carb, which has a square 5 wire connector going into it. Also there is a TPS which is just on the passenger side, and has 3 wires going into it. If the carb has been swapped, those won't be on a non-feedback carb, but the harnesses should still be there.
Also,are there 3 vacuum solenoids on top the valve cover? Are there 3 vacuum switches on the passenger side fender across from the distributor? If yes, your car definitely had a feedback carb at one point.
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I've been working on the air pump removal for the last two hours. I can only take so much bending over the engine compartment so I am taking a break to play with the kids, walk the dog and maybe watch a little TV.
So far I have the air pump out, the air injection manifold off and I cut the hose to the catalytic converter. I removed the carb also to make room to get to the bolts. Good thing I am doing this, the front and rear injection points where broke off the tubes. The rear one is hard to get too as it is right up by the firewall. I still need to get that bolt out so I can plug the hole. It has been leaking badly from the point and has bown oil and carbon all over the backside of the engine.
Everyone keep in mind that when doing this job the valve cover will be very accessible and so will the bolts to the intake and exhasut manifolds. It is a good time to tighten your bolts on the manifolds or loosen them up and replace gaskets. I'm leaning toward putting in new gaskets since I think the original gaskets are still on my engine. Another thing to do since the carb is off, is to remove the EGR and make a block-off plate. I'm also taking out the CTO since I have no vaccum lines going to it right now. Also when I reinstall the carb, I am not going to put the thick plastic spacer back in. It would give me more air space and maybe a couple HP, but I really don't think it is necessary since my adjustment screws are not interferring with the spacer.
Since the valve cover is accessible, I am going to be replacing the origianl plastic one with a new one I ordered last week. It should be in this week so I'll have everything I need.
One more quick note. On my engine, the bolts for the brackets holding the air pump and power steering pump are metric. 15mm I believe. The air injection manifold bolts are 5/8" and most everything else is 9/16". I was missing one nut on the bottom of the air pump as well. Not sure why other than someone must have worked on it at one point and not put the nut back on.
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This section on Wikipedia (http://en.wikipedia.org/wiki/Catalytic_converter#Air_injection) is pretty much the straight poop as I understand it on the way our cat is set up.
That's why, for instance, an engine running rich with upstream air injection stuck on will cause a cat to overheat. Too much fuel.
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That article does give a good understanding of how they operate.
OK, I guess I will get back to it for a little while.
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If it is a feedback carb, there is a stepper motor on the back side of the carb, which has a square 5 wire connector going into it. Also there is a TPS which is just on the passenger side, and has 3 wires going into it. If the carb has been swapped, those won't be on a non-feedback carb, but the harnesses should still be there.
Also,are there 3 vacuum solenoids on top the valve cover? Are there 3 vacuum switches on the passenger side fender across from the distributor? If yes, your car definitely had a feedback carb at one point.
No stepper or stepper plug. None on the emission diagram when I glanced at it too. Tag says 1981 CA emissions certified or words to that effect (Whoa! Wonder if they meant Canada?)
(http://i6.photobucket.com/albums/y209/carnuck/AMC%20Eagle/photo5.jpg)
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No stepper or stepper plug. None on the emission diagram when I glanced at it too. Tag says 1981 CA emissions certified or words to that effect (Whoa! Wonder if they meant Canada?)
It's definitely California, however you can't have air injection and a feedback carb on the same vehicle. The computer's feedback functionality would be disabled by the air dilution. (It's conceptually possible, I bet it has been done.)
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BenM, I beg to differ. I removed a feedback carb and the dual air injection setup on my vehicle. Still in process.
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Dual air injection was used on the 82 models which used the feedback carbs. And 81 Concords/Spirits also have dual air injection with a feedback carb as well. Mine still has it. The computer routes the the air from the air pump to the catalytic converter when the engine is warm. If it injected it into the exhaust manifold, it would completely throw off the O2 sensor. Air was only directed upstream during open loop operation.
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BenM, I beg to differ. I removed a feedback carb and the dual air injection setup on my vehicle. Still in process.
Yeah, you're right and I should have known that; my old parts car was an 82. It seemed like such a complex work-around in my head when I was thinking about it yesterday.
I just checked my feedback system supplement. It doesn't have a diagram of the hoses, though. Does it still use the injection manifold in the exhaust manifold over the exhaust valves?
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It has the air injection manifold still. But the vacuum solenoid on the far passenger side on top of the valve cover controls a valve that either directs air into the manfiold, or into the catalytic converter. When there is no vacuum allowed to the valve, air is directed upstream, when the solenoid turns off, vacuum passes through the solenoid to air valve, and air is directed downstream.
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I don't think the computer controlled all of this switching. There are vaccuum lines that go from the CTO to the air diverter and downstream feed to the cat. When the engine gets hot, the CTO opens to alow vaccuum pressure to switch the diverter on/off. The oxygen sensor would measure the amount of air and the computer would richen or lean the mixture based on those readings.
There is no wiring from the ECO to the air pump or any of the valves on my 82. All controlled by vaccuum and temp sensors.
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I'm sorry but you are incorrect. While all the valves for the air injection systems are all mechanical vacuum valves, the computer does play a large part in it, because the vacuum for those mechanical valves is controlled by the ECM. The CTO valve does not do anything for the air injection system.
(http://i815.photobucket.com/albums/zz79/ammachine390/82vac06.jpg)
In the photo, the solenoids marked "upstream solenoid" and "divert solenoid" are electrical solenoids controlled by the ECM. They are connected to vacuum hoses, when the solenoid is energized by the computer, vacuum does not flow. When they are not energized by the computer, vacuum is allowed to flow. So on a cold startup, the ECM will energize the upstream solenoid, vacuum cannot pass the valve, and the mechanical air valve directs air to the air injection manifold. When the car warms up, the computer de-energizes the solenoid, and vacuum can then pass, which flows to the mechanical air valve, and directs the air to the catalytic converter.
All together, in 1982, the computer did 4 things: control air/fuel mixture, control ignition timing, control air injection solenoids, and controlled idle speed.
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Ok, I give. You are correct. I totally forgot about the two solenoids. I remember taking them out as part of the vac system on the passenger firewall IIRC.
Thanks for clarifying that. This is becoming a great thread for learning about the emissions and vaccuum systems.
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emissions is extremely simple if you install the motorcraft, virtually all vacuum lines except carb -> distributor, 4x4, and cruise can go. cto can be plugged, and the line to the egr valve can simply be removed if it was functioning correctly before being disconnected, since it is naturally closed. the pulse air lines going to the cat can be plugged however you wish (i have mine plugged right before the metal lines going to the cat leave the engine bay since it was easier than welding shut)
then you can hook up carb bowl vent to the canister, and fuel tank to canister, and you're pretty much done.
you can also remove a ton of wiring and the computer itself since all sensors will be inactive without the feedback carb. i took out mine and about half the wiring harness came with it.
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I'm removing the EGR and CTO as well. I want to remove the computer at some point. I will save that project for another day.
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Be sure if you are to retain your A/C that you hook that vacuum line back up to your heater controls as well, not needed with the upgraded carb though.
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forgot to mention the computer is hidden beneath the passenger side wall trim panel under the dash. you'll know it when you see it...
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I'm taking the vacuum line diverter valves and all of that out. I am also removing the heater hoses as they are routed more directly without AC.
The computer will stay as is until later this year when i do the interior work. Then it will come out.
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i gotcha. it took around 2 hours of painstaking wire tracing to ensure proper removal...i was much less careful with the vacuum lines. are you using a motorcraft? there are also two vacuum switches on the passenger fender that can come out as they aren't used if the compute is inactive or out. if you need diagrams or pictures i can help
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No computer in mine. It IS (was) a Canadian car! Likely interior of BC since there is no rust on it. I'll take a better pic of the emission tag later. When I adjusted the shifter linkage I found out the cat wasn't OEM and the feed pipe to the cat was just there for show (I removed it in pieces as the cat inlet was still capped) and left the manifold AIR injection alone (for now)
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i gotcha. it took around 2 hours of painstaking wire tracing to ensure proper removal...i was much less careful with the vacuum lines. are you using a motorcraft? there are also two vacuum switches on the passenger fender that can come out as they aren't used if the compute is inactive or out. if you need diagrams or pictures i can help
I'll take whatever you've got when it comes to that! Thanks.
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No computer in mine. It IS (was) a Canadian car! Likely interior of BC since there is no rust on it. I'll take a better pic of the emission tag later. When I adjusted the shifter linkage I found out the cat wasn't OEM and the feed pipe to the cat was just there for show (I removed it in pieces as the cat inlet was still capped) and left the manifold AIR injection alone (for now)
Canadian Eagles have no cat converters.
They did from the factory. They may have rotted off soon after though :rotfl:
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Nope. Not even from the factory. No cats on Canadian Eagles.
They did from the factory. They may have rotted off soon after though :rotfl:
I think the early Canadian model years did not have them, but I think they were added during one of the model years.
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Maybe mine was installed to meet US emissions coming in? E test is required here
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Maybe mine was installed to meet US emissions coming in? E test is required here
For purposes of this discussion its probably important to diferentiate between cars that were manufactured in Canada vs. those that were delivered to Canada
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I'm at the point where I will be putting the engine back together soon and running new hoses and all that. When I'm done, I'll take a picture and post the before and after so everyone can see what is involved. I intended to do a write-up but it was too much to take pictures while taking things apart since they were so greasy and dirty.
I think before/after pics and a picture of the removed components laid out will give a good idea of what it takes.
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My tag says "Meets Canadian emissions requirements for 1981 year"