SMOG help

[Mavrick70004]

My 85 ranger failed smog today, it failed becuase of High HC, High CO and High Nox. Truck has 117xxx miles. Any suggestions?

 

[kimcrwbr1]

Have you ran the codes go thru and check cleann all the electrical connections and grounds give it a good tune up wires plugs cap rotor check all your vacuum lines for leaks and routed properly. when the engine is idleing pull a vacuum on the egr it should stall. You can get a code reader at the part store EEC-IV/OBD-1 and run the codes. Then get back with us with the results.

 

[Mavrick70004]

i have not run codes as of today... i did see my air pump hose was off i must have forgotten to put it back on ( my exhaust check valves are no good so the exhaust pops and removing the air hose stops the popping ). Should my engine be warmed up before pulling the EGR ? I did it cold and nothing happened and there was no suction at the vacuum line

 

[kimcrwbr1]

you need a vacuum pump or take a vacuum line from the tree behind the carb and hook up vacuum pressure to the egr while the engine is idleing to open the valve all the way if the engine dont stall either the egr is not working or the ports on the heads are plugged. When you pull the codes code 31 is the egr and usually the nasty one to make go away. does your engine blow smoke when you start it usually a sign of valve guide seals and what causes the egr to plug up. You can get new check valves for the air system and could be the whole of the problem and if the check valves go bad more than likely the bypass valve or thermactor got fried internally from the hot gasses I would check them also for proper operation. You can use the engine vacuum to test the air flow on both the thermactor changes from manifold to cat and basically always leak a little just keep the pump connected to then and try giving them vacuum pressure the thermactor should switch between the two and the bypass just turns the air off to the system and blow air out the side thru the filter thing actually acts as a noise supressor.

 

[Mavrick70004]

hooked a hose up to the egr and sucked on it and the engine stalled. the engine does blow smoke when i start it up and i do have valve seals and valve cover gaskets but they are not put on yet. the first diverter valve thingy is open when vacuum is applied to it and the air is pushed into the second diverter. When the vacuum is disconnected it is closed and no air is at the second diverter. The second diverter is pushing air to the cat and to the manifold but i thought i read somewhere that the second diverter is supposed to apply air to both outlets and the vacuum line just modulates how much air is sent to each outlet like 60% to the cat 40% to the manifolds, I could be wrong though. I'm going back tomorrow to get another test and see what happens with the Air pump reconnected , worst case it still fails but my numbers will be lower.

 

[dangerranger83]

Changing out the valve seals will help a bunch. Another guy on here had a heck of a time passing cali. emissions and in the end had to get a new CAT and passed after that (after doing all this stuff to his truck too).

 

[Mavrick70004]

With the air pump connected a drove around a while and pulled: KOEO 11: Pass KOER: 23,25,41,77: pretty sure i just need a new knock sensor so that takes care of 25, code 23 says to fix code 41 first so with 110xxx miles ima replace the O2 sensor and then 77 is a code that i have always gotten even though i do the goose test and maybe has to do with the TPS and code 23? not sure. i don't think TPS would cause a emission failure? maybe lil rough idle or something like that so ima replace the O2 and get smog'd if it fails then ill replace the cat and see what happens.

 

[enginepaul]

I'm not near my manual. so it may be a while before I can look to see what the factory says about those codes BUT fixing by replacing parts can be an expensive waste of time. The TPS can cause a failure - like any other part - because they work as a system. The sensors feed the computer information that adjusts things so the ignition and timing are just right.
In general; you fix the lowest error code first.
ALSO: one of the first things the manual says is "inspect the contacts" on the sensors as you check them. I spent lots of time and money trying to correct a problem and found that one of the pins (worth about 50 cents) was the problem all along. So go slow and check the wires and contacts as you remove parts.

 

[litleblue]

Code 41 means the O2 sensor is seeing a lean condition. Don't think the sensor is bad. Most likely when you replace the sensor the code will return. The 77 should go away if you quickly depress the throttle between the seperator code and when the first code is transmitted. Ie. after the first "1" or "11" and maybe "3" (the three means how many cylinders fire in one reveloution of the engine) I can't recall the order of these first three codes. Code 23 is the TPS is out of range. Also if you are doing the "goose test" at the right time the TPS could be bad.

Check the wiring and the referance voltage to the TPS. Also take a ohm meeter and test the resistance vs throttle position. If the resitance is is not smooth increasing and decreasing while actuating the throttle then replace the sensor.

Then unplug the Knock sensor take the truck for a drive and see if the engine starts to ping real bad. If the engine starts pinging real bad unplugged, and then if you reconnect the sensor and the pinging stops, then the knock sensor is OK. Blow the code off. You might get the code to clear by taking a very small hammer and lightly tapping the exhaust manifold while performing the KOER test. The code might go away.

The 41 code is an engine too lean code or O2 slow switching. Not the O2 sensor is bad code! (That is code 43) If the engine vacuum system is tight and I mean everything, manifold, carb, spacers, EGR valve, vacuum lines, vacuum reservoir! solinoid valves, vacuum motors, and all of the other BS that can cause a vacuum leak. Then I would look at the Feedback solinoid on the back of the carb as well as the condition of the carb. The feedback solinoid is very overlooked part for a slight miss at idle. Over the years the rubber parts in the valve go bad and the valve wont seal, allowing air to be be bypassed into the emultion tubes in the carb. This will lean out the engine allowing the HC's to increase at idle. IN addition it might be time to clean out and re-tune the carb by propane gain method. BTW it would be a good idea to change the O2 sensor after you have checked all of these things they do wear out and get lazy, the last one I bought from NAPA was 13 dollars.

Dont be frustrated, these are all very, very common codes for a 2.8 FBC EECIV engine. The most common parts to fail on this vehicle are the TPS, TFI module, Vacuum leaks!!!!!!!!, Feedback Solinoid,and O2 sensor. everything else is pretty reliable.

Hope this helps

 

[Mavrick70004]

Unfortunately my truck is now sitting in the parking lot at my work because it failed to start last night, had spark and had fuel and i drove it their just fine so i would assume it has compression, i pulled off the air cleaner and the carb and intake were wet from fuel but the little jets in the carb still spit out a stream of gas when depressed so im HOPING it got REALLY flooded. I did replace the O2 sensor and the TFI so only 2 more things to change haha. If it is the feedback solenoid would it make sense for the mixture to go rich and then lean? I pulled codes a couple times right after each other and one time i got a code for the engine running rich and then the next time i got a code for running lean, its funny you say it could cause a slight misfire at idle because that's what my truck does and i cant track down what is causing it, everything above idle is just fine and the engine screams and has full power at WOT. As for vacuum leaks a spray bottle with water and spray around where there could be vacuum leaks and the engine will stumble or something like that correct?

 

[litleblue]

I don't think the water idea will get the results you may be looking for. IT will take a long time for the water to find its way to the cylinders and the amount of water to make this happen will be considerable.

First choice, I would use propane to find vacuum leaks. Second and conideribaly more dangerous would be Starting fluid with a long point lubricator connected to the spray nozzle. Both have advantages and dissadvantages. Brakleen, go boom real fast. Propane is kind of a pain in the ass since it will stay in the engine compartment for a couple of seconds and then you wont know where the leak is untill you let the gas dissapate.

You might be able to come up with cheep valve to attach to the top of a small one pound propane cylinder. Then hook a 1/8" to 1/4" hose to the valve. Slowly open the valve and just let a tiny bit of gas to continously excape from the tube. Take the end of the tube and place it on the vacuum connections, carb base, manifold head interfaces etc. If there is a vacuum leak the engine idle will increase maby up to 50 RPM. If you notice a increase either by hearing a change in engine speed or watching a tach. remove the tube and watch or listen for a decrease in RPM. Do this a couple of times, get repeatable changes, you have found the leak. I have also sparingly used Brakleen/ starting fluid the same way but wouldent recommend it.

Unfortunatly this sounds much easier than it really is.

 

[kimcrwbr1]

Did you reset the computer every time you change/clean a sensor. Run the koeo test and when it starts flashing codes turn the switch to hold and that will erase the memory then disconnect the battery for 1/2 an hour to reset the computer. Then run it for about 20 minutes at medium speeds until fully warm then run the codes again you need to do this every time you change or clean a sensor and always fix the lowest code first and get it to go away they are in order for a reason and one bad sensor can throw multiple codes. the easy way to test your knock sensor is put it on a timing light and have someone tap on the block next to the sensor the timing should retard with the tapping just dont hit the sensor they break real easy. You can erase the memory any time but you only need to reset the computer when you change a sensor and set the new values by running it for 20 mins.

 

[Mavrick70004]

New problem with the truck so now i cant even go to get it smogged. Started after i replaced the O2 sensor, truck still idled a little rough so i played with the timing a little bit but this did nothing so i put it back to where i thought it was before. On the way to work the truck stumbled when taking off and when going to WOT, if i stomped on the throttle a couple times it would get past the stumble and then go to full RPM and would be fine until the rpm came back down then it would do the same thing over again. After work the truck would not start, it had spark and fuel but would not get going. I left it there over night and came and got in it the morning same thing, would not start. After cranking it until the battery went dead i got a jump and then cranked it for about 15 seconds and it started. Ran like S**t until i got to my shop and found the timing to be at 0. Put the timing back to 14 and it got better, left it on the charger all night. Came back this morning and would not start again, the only way it starts when its cold is to crank it and pump the gas at the same time then after a couple seconds it will start. drove it up and down the street a couple times and put some gas in it. The stumbling would come and go. Then at a stop sign the truck died and once again i had to crank and pump for it to start. It sounded like an ignition or timing problem up until the truck died while i was driving it and then would not start until i cranked it and pumped the gas then it seemed to me to be some sort of fuel problem? anyone give me some advice

 

[litleblue]

Start out with the basics. First set the timing, cylinder #1 to 10 DEG BTDC. with the spout connector disconnected. (Single wire connector thet runs to the distributor usually green with yellow tracer.) Then rehook up the spout connector. Leave the timing light connected run KOER test. At the end of the test (all codes repeted twice) the computor should set the timing to 27 DEG BTDC. +-2 DEG. If it is still 10 BTDC then look for broken spout wire and there should have been a code 14 maybe 18 I cant remember. Once this is straightened out then start working on the fuel system.

Make sure all of the vacuum connections are correct and TIGHT!

Make sure the carb is in resonable shape, TPS, Feedback solinoid is ok ect.

Take EGR Valve off of adaptor and see how much carbon and shit are in the passages. If is close to being plugged the intake manifold cross over tube might be plugged. If you understand how the passages run through the manifold some times you can break most of the carbon out with a wire or speedometer cable on the end of a drill. I usuall just remove the manifold and just clean it out. A real pain in the ass but something that has to be done every few years. This could also be the problems with the emissions if the passages are plugged not allowing any exhaust gasses to be injected into the manifold. A NOX. test in the manifold before the cat will tell the operation of the EGR system.

To me it sounds like you are having the same problems they are just manifesting themselves in diffrent ways.

 

[kimcrwbr1]

+1 on the egr get it to idle and add vacuum to the egr the engine should stall. If you are going to take the egr off to check it get a new gasket for it first as the old one probably wont work again. with it off blow on the hole without the valve in it and it should not leak if it does put your thumb over the valve side pushing it in and blow again to see if the upper seal is leaking. My egr was bad but it didnt matter because the ports on the heads were plugged. The air pump has nothing to do with the egr the way the egr works is it puts burnt exhaust gasses ito the combustion chamber to essentially thin out the oxygen in the chamber so the fuel burns cooler thus lowering the output of the bad gasses. I always thought how can putting hot gas in the cylinder lower combustion temps, it displaces the oxygen going in to reduce the CO levels in the burn. If you egr is really plugged and dont affect the idle much it is usually a sign of bad valve guide seals. Do your plugs look brown or black when you pull them. Mine blew smoke when I started it but after changing the seals the plugs burn nice and clean now. Here is the link for valve guide seals http://www.therangerstation.com/tech_library/2_8L_Performance.html and pulling the intake manifol to open the exhaust ports for the egr is the only way I know of to open them up if they are plugged all the way. GL