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Discussion Starter #1
Alright here we go have a rough idle and rough start up but when i apply vacuume to the passenger side diverter valve it runs smooth what could this be ive replaced egr all vac lines with silicone lines new tps its weird it runs alot better when i apply vacuume on that one valve ...
 

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Yo C,
DTC 311 Thermactor air system inoperable. "...The computer determined that for some reason the fresh air injection from the Thermactor system was not present. There are several components that make up this system. The initial component is the smog pump. The first checks I would make are the hoses and plumbing from the smog pump back to the diverter valve (behind the pass. cylinder head) and then on to the crossover pipe at the back of the heads and down to the catalytic converter. The check valves that are at the center of the cross over pipe and the top of the metal tube from the cat are often the culprits as they can and do snap in half as the get old. If the plumbing looks to be in good order we can discuss the slightly more complicated aspects of the system. The diverter valve also has two vacuum lines running to it. Make certain they are in place and intact. (Computer needs to be able to control the flow of fresh air by the Thermactor system)..."
Source: by greystreak92

DTC 311, 312, 313 & 314; "...311 and 314 indicate the Secondary Air Injection system is inoperative. DTC 312 indicates that Secondary Air is misdirected. DTC 313 indicates that Secondary Air is not being bypassed when requested. Possible causes: Visually inspect vacuum lines for disconnects in the AIR system. Visually inspect for proper vacuum line routing. Refer to VECI decal. Visually inspect Air Pump for broken or loose Air Pump Belt. Refer to Section 13A for adjustment/replacement..." READ MUCH MORE
Source: by Jim
 

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Discussion Starter #3
Well ive check all pluming... all seems to be good but what i have noticed is that the smop pump is not pumping alot of air it seems weaker than before would that cause the o2 sensor to read differently and start to run like crap? when warm ive checked the check valve at the bottom and the two diverter valves and they seem to be good and working properly no crackes in the crossover tube or pipe going to the converter..
 

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Well ive check all pluming... all seems to be good but what i have noticed is that the smop pump is not pumping alot of air it seems weaker than before would that cause the o2 sensor to read differently and start to run like crap? when warm ive checked the check valve at the bottom and the two diverter valves and they seem to be good and working properly no crackes in the crossover tube or pipe going to the converter..
yo Cole,
The pump could be the issue; is it more noisy than usual?
Test; "
1.Check and, if necessary, adjust the belt tension. Press at the mid-point of the belt's longest straight run. You should be able to depress the belt about 1/2 in. (13mm) at most.
2.Run the engine to normal operating temperature and let it idle.
3.Disconnect the air supply hose from the bypass control valve. If the pump is operating properly, airflow should be felt at the pump outlet. The flow should increase as you increase the engine speed. The pump is not serviceable and should be replaced if it is not functioning properly.

Operational Description & pic; This pumps fresh air into the exhaust system , to burn left over hydrocarbons, lowering emissions. The computer uses 2 air valves (TAB & TAD) to control where the air flows depending on engine operation. Thermactor Air Bypass (TAB) shunts air to the atmosphere, when no air is needed. When air is needed it sends air to the second valve TAD. Thermactor Air Diverter (TAD) diverts air either to the exhaust manifold, or [directly to catalytic converter.[/B]
MIESK5 NOTE; If Engine Coolant Temperature Sensor (ECT) is Below 50 degrees F, then TAB is grounded & sends air to atmosphere; If Between 50 and 190 Degrees F, Bypass Valve sends air to Diverter and to Manifold; If Over 190 Degrees F, it is in closed loop & Air goes to Catalytic Converter; Bypass when at idle/Wide Open Throttle (WOT), and with failing Oxygen Sensor. The fastest way to see if vehicle is in open loop is to see where the air is going; to Catalytic Converter, it is in Closed Loop; to Atmosphere or Manifold it is in Closed Loop, provided the thermactor system is working' ...And for the fuel that wasn't burned in the combustion chamber, we need extra airflow pumped into the exhaust system. This air with the heat of the exhaust creates further break down of HC, CO, and Nox into CO2, H2O, and N2. The catalytic converter can accept all of the airflow without fear of over heating during cruise. We need hot exhaust gasses to help complete combustion and converter operation. Air is pumped into the converter, but will dump to the atmosphere after several minutes to prevent overheating the converter. The converter is cooled by air passing under the vehicle..." READ MORE
Source: by Ryan M (Fireguy50)

Preventing Smog Pump Seizures, General; "...Before installing replacement unit, [test check valve(s) for proper operation. Air should pass through valve only in one direction. These valves prevent exhaust gases from entering the unit. DO NOT install pump with a defective check valve. Check the PCV system for proper operation. An inoperative or defective PCV system allows oil and gas fumes to enter Smog Pump, causing bearing failure. Water contamination causes bearing corrosion, internal component damage, or housing failure. To help prevent this problem, carefully inspect all hoses, make sure fittings are secure, pump filters are not clogged, and the fan is not damaged. Be careful when washing the engine and, on low-mounted units, avoid driving through high water. Cover pump when washing motor..."
Source: by cardone.com

How is engine vacuum? Normal Engine Vacuum at Idle is 15-22
See my Vacuum Leak Test @ http://fullsizebronco.com/forum/showthread.php?t=206824&highlight=Vacuum+Leak+Test;+idling
post #11
 

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Discussion Starter #5
The pump is not noisey at all it just does not seem like it blowing alot of air my other bronco blows tons on air
 

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yo Cole,

Inspect ck valve and replace if it is damaged by Rust or a hose is bad, etc.
Check Valve Depiction; The air check valve is a oneway valve that allows thermactor air to pass into the exhaust system while preventing gases from passing in the opposite direction.

"When vacuum leaks are indicated, search out and correct the condition. Excess air leaking into the system will upset the fuel mixture and cause conditions such as rough idle, missing on acceleration, or burned valves. If the leak exists in an accessory unit, such as the power brake, the unit will not function correctly. ALWAYS SERVICE VACUUM LEAKS." by Ford
 

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Discussion Starter #8
Alright well i took off the crossover tube and there were not and gaskets on either end could this cause a vacuume leak please explain
 

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yo Cole,

The vacuum circuit does not include the crossover tube, but is connected to the various valves and devices as shown I below diagram;
Vacuum Line Routing Diagram in a 93 5.8
Source: by bronco5.8 (Sam) at http://web.archive.org/web/20141228...attach&attach_rel_module=post&attach_id=10584


Overview & Diagram; "...Secondary Air Injection system consists of a belt-driven Air Pump, single or dual AIR Diverter valve(s), an AIR Bypass valve, and AIR Bypass solenoids, air silencer/filter, Powertrain Control Module and connecting wires and vacuum hoses. The Belt-Driven Secondary Air Injection system provides either upstream/bypass air or upstream/downstream/bypass air. The number of these system configurations vary significantly with AIR Bypass and AIR Diverter valve combinations (Figure 179). 2. The PCM provides one or more signals that enable one or more AIR Bypass solenoids. 3. The AIR Bypass solenoids control one or more AIR Bypass valves and/or AIR Bypass Diverter Valves in order to route secondary air depending upon the specific configuration. 4. The belt-driven Air Pump is operational any time the engine is running..." read more
Source: by Steve83 http://www.supermotors.net/registry/media/589993

See vacuum circuit (lines) from Coffee Can Reservoir to TAB & TAD and Bypass/Diverter valve

Also, did you do the test as described by Jim including part KC5 CHECK AIRB AND AIRD SOLENOIDS ELECTRICAL OPERATION in my post #2?
 

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Discussion Starter #10
Then i have no clue ive check tad and tab valves to make sure there working all the plumbing looks great all vacuume line are new the only thing i have seen is the smog pump blows small amount of air and the top cjeck valve leak some air ....
 

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yo Cole;
ok, did you do the test as described by Jim including part KC5 CHECK AIRB AND AIRD SOLENOIDS ELECTRICAL OPERATION in my post #2?
 

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Discussion Starter #12
Alright ive tested all the sensors ive replaced both check valves and both diverter valves the motor stumbles alot at idle but seems to be fine while driving its runs better asoon as i unplugged the o2 sensor map sensor is new o2 sensor is new i dont under stand why it would run better with o2 sensor unplugged????
 

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Yo Cole;
I asked about performing that test because it is what a Ford tech would do for the 311 Code and is better than replacing parts.

Also, can you check vacuum reading?

back to your original Q on the Diverter valve;
Functional Test; "...1.Run the engine to normal operating temperature, then increase the speed to 1500 rpm. 2.Disconnect the air supply hose at the valve inlet and verify that there is airflow present. 3.Reconnect the air supply hose. 4.Disconnect both air supply hoses. 5.Disconnect the vacuum hose from the valve. 6.With the engine running at 1,500 rpm, airflow should be felt and heard at the outlet on the side of the valve, with no airflow heard or felt at the outlet opposite the vacuum nipple. 7.Shut off the engine. 8.Using a spare piece of vacuum hose, connect direct manifold vacuum to the valve's vacuum fitting. Airflow should be heard and felt at the outlet opposite the vacuum nipple, and no airflow should be present at the other outlet. 9.If the valve is not functioning properly, replace it..."
Source: by Chilton
& as Steve83 wrote "The vacuum controls leak (including the "coffee can" reservoir on the R wheelwell), get misrouted during other repairs, or the diaphragms rupture...The early steel coffee can reservoir commonly rusts &/or cracks, and the later plastic reservoir is an easy upgrade"


Any Codes for the O2 or MAP?

O2 Testing; "
Testing, General; "...All you need to test an oxygen sensor is a propane torch, vise grips, ans a 10 Meg ohn input impedance meter capable of measuring low voltages (1 volt and less). If you going to buy one, ask for a highimpedance (10,000 ohms) digital type. Connect the voltmeter, as shown in the photo. Then heat the tip of the sensor, holding the tip completely in the flame. Move the torch flame over the sensor tip. The tip should be hot enough to turn cherry red, and the flame must enter the opening into the sensor tip. Meranwhile, keep an eye on your meter. If you get a reading above 600 millivolts, and the reading quickly changes with the movement of the flame over the tip, the sensor. NOTE: Testing a sensor with a meter other than the above specified type will destroy the oxygen sensor and any related computer circuits, if connected..."
Source: by tomco-inc.com

...You can test them, but usually if there's more than ~30k miles on them, I wouldn't bother. I treat them just like spark plugs, as they DO wear out and stop performing like they're supposed to. In fact, the EEC is programmed to observe the HEGO signal and count crossovers to determine the relativistic age of the sensor, and to compensate for it. Usually the cost of HEGOs is more than paid for in terms of mileage and driveability increases, at least IMHO. MANY reference literatures state that you can test them with a voltmeter and a heat source such as a propane torch, or even right in the vehicle. This is bull to me; HEGOs generate voltage through a galvanic reaction, and it's nothing like a DC source such as a battery. They 'swing' high to low, and 'center' around a value to tell the EEC what the mixture is approximately. Also, HEGOs are accurate only within a very very narrow range, something on the order of 14.2:1 to 15:1 (don't have my references here in front of me, sorry). So that bench testing crap won't fly too well. The real problem is reading what the HEGO is outputting without that special circuitry. Many people make do with a resistor (or shunt of some sort) and a DVOM, but it's not accurate enough for ME to accept as reliable..."
Source: by SigEpBlue (Steve) at FSB

MAP Testing, Symptoms & Overview; "...a multimeter that can read frequency is normally required to check the sensor’s output. But you can also use an ordinary tachometer because a tach can display a frequency signal. Here’s the procedure: Connect the two jumper cables the same as before, (see diagram in site) attaching each end terminal on the sensor to its respective wire in the wiring connector. If you want to measure engine vacuum so you can correlate it to a specific frequency reading, connect a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Turn the ignition ON and note the initial reading. The reading on the tachometer should be about 454 to 464 at sea level, which corresponds to a frequency output of 152 to 155 Hz. Start the engine and check the reading again. If the MAP sensor is functioning properly, the reading should drop to about 290 to 330 on the tachometer, which corresponds to a frequency output of about 93 to 98 Hz. No change would indicate a defective sensor or leaky or plugged vacuum hose..." a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose.
Source: by wellsmfgcorp.com
 

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Discussion Starter #14
Alright i checked that the valve is working correctly in getting air at the right times i keep forgetting every time i start the truck after turning it off it seems like the idle still take alittle time to get back down to normal idle like when i rev the motor is seem like it take longer for it to return to idle the bad idle is like it drops off for a split second then run good then drops off and thats when the motor shakes like something is not set right this really hard to explain... its like my motor has turrets syndrom lol sorry that the best way to describe it
 

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Alright i checked that the valve is working correctly in getting air at the right times i keep forgetting every time i start the truck after turning it off it seems like the idle still take alittle time to get back down to normal idle like when i rev the motor is seem like it take longer for it to return to idle the bad idle is like it drops off for a split second then run good then drops off and thats when the motor shakes like something is not set right this really hard to explain... its like my motor has turrets syndrom lol sorry that the best way to describe it
yo,
Ok, that valve test helps!


EDIT: As a possibility although you reported No IAC related Codes;

Overview & Testing; "First let me say this little thing has many names. But they all talk about the same item under the hood. Here all the names I’ve had the torture of learning throughout the years: Idle Air Bypass •Idle Air Control •Idle Speed Control •Throttle Bypass Air •Idle Bypass •Inlet Air Controller •Inlet Air Bypass •Intake Air Bypass •Intake Air Control..."
Source: by Ryan M (Fireguy50) http://web.archive.org/web/20101201013829/http://fordfuelinjection.com/index.php?p=39

Removal & Cleaning in a 93 5.8
Source: by Bobby (blue) at http://fullsizebronco.com/forum/showthread.php?t=25878

Long Crank Times may be traced to a sticking Idle Air Control (IAC) valve, TSB 97-9-5 for 95-96 by Ford via Steve83
http://www.supermotors.net/registry/media/470492

Read Sensor IAC Gasket mod by Nelbur @ http://broncozone.com/topic/22150-fast-idle-problem/?&pid=115710


Sensor IAC and Spacer Kit by Seattle FSB
http://www.fullsizebronco.com/forum/showthread.php?t=353537

can you check vacuum reading?;
HOOK UP THE GAUGE TO MANIOLD TEE WITH a tee ADAPTER
 

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Discussion Starter #16
I found out that when i apply vacuum to the yellow vacuum line that goes to tad valve it runs alot better if not great its allowing air to go to the heads whats the deal i wanna fix it right but dont know what to replace is the head suppose to get air normally?? Explain what the smog pump air does exactly at idle??
 

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Discussion Starter #18
Well Guys... The only thing i have found was that if the smog pump pumps air to the heads it runs a lot smoother, I just cannot figure out why?? The TAD and TAB valves seem to be working like they should... I do know my smog pump is starting to make noise but i don't think it would cause the motor to stumble like this. As of now i have the yellow vacuum line connected to the main vacuum tree and like i said it runs a lot better.. like the o2 sensor is getting a decent reading, Any help is much appreciated.



I have no idea why is posted twice sorry!!!!
 
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