|
Idle issue. Codes read thermactor #313
1993 e350 club wagon 5.8 351 with 100,000 miles. Idles up and down while warming up. Once warmed up, idles down and fixes itself repeatedly at stop lights while in drive. Replaced computer properly. Then replaced pcv valve, fuel regulator, air filter, fuel filter, cap, rotor, plugs, temp sensor, both vacuum solenoids (TAD & TAB). Codes read 311 and 313. After replacing the vacuum solinoids codes read 313 only- “Thermactor air not being bypassed.” Air pump works fine and no vacuum leaks to be found. Problem still exists. Please help y’all. Can’t afford to keep throwing money at this thing. might be a clogged cat? Oh yeah and timing is on point as well |
There are two valves as part of the emission system. One is , TAD, thermal air divert, and the other is TAB, thermal air by-pass. Air coming off the air injection pump is directed to both of those two valves depending on engine temp and operating conditions.One valve directs air to the exhaust manifold to complete burning of the fuel, and when the engine warms enough that valve directs the air to the converter.That is the by-pass valve.
When decelerating air is diverted to the air cleaner to prevent backfire. .There are temperature controlled vacuum valves that allow vacuum to the solenoids on each valve and the EEC determines when they should operate. Those valves had some problems with carbon accumulation and would stick or not work at all. The self test checks the electrical portion of the valve and that can be verified by checking the solenoid in the valve with an ohmmeter. If it reads infinity , the solenoid is open and the valve requires replacement. If it reads as specs state, there could be a wiring problem or computer problem. Not sure if those valves are available these days. Was a common problem. |
Originally Posted by hanky
(Post 110127)
There are two valves as part of the emission system. One is , TAD, thermal air divert, and the other is TAB, thermal air by-pass. Air coming off the air injection pump is directed to both of those two valves depending on engine temp and operating conditions.One valve directs air to the exhaust manifold to complete burning of the fuel, and when the engine warms enough that valve directs the air to the converter.That is the by-pass valve.
When decelerating air is diverted to the air cleaner to prevent backfire. .There are temperature controlled vacuum valves that allow vacuum to the solenoids on each valve and the EEC determines when they should operate. Those valves had some problems with carbon accumulation and would stick or not work at all. The self test checks the electrical portion of the valve and that can be verified by checking the solenoid in the valve with an ohmmeter. If it reads infinity , the solenoid is open and the valve requires replacement. If it reads as specs state, there could be a wiring problem or computer problem. Not sure if those valves are available these days. Was a common problem. |
Don't forget the vacuum to some of those valves is controlled by the thermal vacuum switches , a thorough check for manifold vacuum and then vacuum present after engine warm up is a good move to confirm.
|
| All times are GMT -5. The time now is 03:19 PM. |
© 2024 MH Sub I, LLC dba Internet Brands