Thermactor Air System?

Tiny
MUSTANGSHAWN
  • MEMBER
  • 1988 FORD MUSTANG
  • V8
  • 2WD
  • AUTOMATIC
  • 116,000 MILES
I have an '88 Mustang GT that will run fine for 30 mins. One time and all day the next day and then quits but if I keep it around 2,000 rpm's I can keep it running until I can get it home. The fault codes are 94- thermactor air system problem right bank(passenger side) and 44 thermactor air system failure. Once it dies I have a lot of trouble getting it started again. I have replaced the fuel pump, strainer, filter, IAC valve, and TPS. The only thing left is ICM or a stick of dynamite, but I don't know where to go from here.
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Thursday, June 23rd, 2011 AT 1:44 AM

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Tiny
RASMATAZ
  • MEMBER
AIR PUMP

Check belt tension and adjust to specification. Disconnect air supply hose from control valve. Observe airflow from pump outlet with engine running. Flow should increase as engine speed is increased.
AIR BY-PASS VALVE
Normally Open Valve Without Vacuum Vent
With engine at normal operating temperature, parking brake applied, and transmission in Park or Neutral, disconnect air supply line at valve outlet. Disconnect vacuum line at vacuum nipple.
With engine at 1500 RPM, air should be heard and felt at valve outlet. Connect a direct vacuum line from any manifold vacuum source to vacuum nipple on valve. Air at outlet should be momentarily decreased. Air pump supply air should be heard at silencer ports.
Reconnect vacuum and thermactor lines. If valve fails any test, and air pump functions properly, replace valve.
Normally Open Valve With Vacuum Vent
With engine at normal operating temperature, parking brake applied, and transmission in Park or Neutral, disconnect air supply line at valve outlet. Disconnect all vacuum lines from vacuum nipple and vent.
With engine at 1500 RPM, air pump supply should be heard and felt at outlet. Connect a vacuum line from vacuum nipple to one of vacuum fittings on intake manifold. With vacuum vent open to atmosphere and engine speed at 1500 RPM, no air should be felt at outlet, since all air is by-passed through silencer ports.
Using same direct line to an intake manifold vacuum source, cap vacuum vent. Increase engine speed to 2000 RPM and suddenly release throttle. A momentary interruption of air pump supply should be felt at valve outlet.
If valve fails any test and air pump is operating properly, replace valve. Reconnect all vacuum and thermactor lines.
Normally Closed Valve
With engine at normal operating temperature, parking brake applied, and transmission in Park or Neutral, disconnect air supply line at valve outlet. Remove vacuum line and ensure that a vacuum signal is present at nipple.
Remove any delay valves or restrictors in line. Vacuum must be present at nipple before proceeding. With engine speed at 1500 RPM and vacuum line connected to nipple, air pump supply air should be heard and felt at outlet.
With engine at 1500 RPM, disconnect vacuum line. Air at outlet should be significantly decreased or shut-off. Air pump supply air should be heard or felt at silencer ports.
If valve fails any test and air pump is operating properly, replace valve. Reconnect all vacuum lines.
AIR BY-PASS/AIR CONTROL VALVE
Normally Closed Valve
With engine at normal operating temperature, parking brake applied, and transmission in Park or Neutral, disconnect hoses from ports "A" and "B". See Fig. 4. Disconnect and plug line to port "D". With engine speed at 1500 RPM, air should flow from by-pass vents.
Reconnect line to port "D". Disconnect and plug line to port "S". Ensure vacuum is present in line to port "D". With engine speed at 1500 RPM, air should flow from port "B", and no air should flow from port "A".
Apply 8-10 in. Hg vacuum to port "S". With engine speed at 1500 RPM, air should flow from port "A". If valve has a vacuum bleed, some lesser amount of air will flow from port "A" or "B", and main discharge will change when vacuum is applied to port "S".
If valve fails any test, it must be replaced. Reconnect all vacuum hoses.
AIR SUPPLY CONTROL VALVE
Verify that air is being supplied to valve inlet by disconnecting inlet supply hose. Disconnect hoses at valve outlets "A", "B", and at vacuum nipple. With engine speed at 1500 RPM, airflow should be heard and felt at valve outlet "B", and little or no air at valve outlet "A". See Fig. 3.
Using a direct vacuum line from manifold vacuum source, connect line to vacuum nipple. Airflow should be detected at valve outlet "A", and little or no air at valve outlet "B". If valve fails any test, replace valve. Reconnect all lines.
VACUUM CHECK VALVE
Apply 16 in. Hg vacuum to check side of valve and trap. If vacuum remains greater than 15 in. Hg for 10 seconds, valve operation is normal. If not, replace valve.
IDLE TRACKING SWITCH
When throttle stop lever is against idle tracking switch, switch is open, and there should be no continuity.
PULSE AIR VALVE
With engine at normal operating temperature and at curb idle, a suction should be felt at valve inlet. If not, replace valve.
THERMACTOR IDLE VACUUM VALVE
Disconnect vacuum hoses from valve. Connect a manifold vacuum source to small nipple of the TIV valve. With engine at idle and in Neutral, test for vacuum at vent holes in valve housing. If vacuum is not present, valve must be replaced.
With engine running and connected as in step 1), use a test source to apply vacuum or pressure (within specified range) to large nipple. If vacuum is present at vent holes, valve must be replaced. Disconnect test hoses and reconnect original hoses.
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Thursday, June 23rd, 2011 AT 3:50 AM

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