Well, I finally pulled the codes and I'm happy to say I got a code 11 on the KOEO test, but I got a code 44 on the KOER test. Didn't get any continues codes. This is the air pump system if I'm correct. Any ideas on where this problem is. I'm thinking one of those vaccum valves aren't opening. This makes sense because at my last smokecheck I had alot of unburned fuel emission. They told me "it's probably the CAT, you need a new one." I said no to that, this ones only got 30,000 on it. Of course they said "those aftermarket ones aren't any good." So I guess I'm not getting any fresh air into the exhaust to help it all burn up. Anyone have any suggestion or had this code and fixed it? What about the TAB and whaterever is in that box by the battery?

 

By the way, it's an 86 F-150 302 EECIV EFI.

 

The Haynes manual explains how the thermactor system works and how to diagnose that problem.

 

My TAD doesn't seem to be controlling vaccum correctly, shut's it off to the diverter valve too soon. I'm going to replace it along with the TAB (they are together as a unit) and see if it fixes the problem. If not, it may be the computer.

 

Well, I'm going to forget about buying the new TAD-TAB module, it was discontinued by Ford earlier this year. If you can find one, it's $99 plus tax. I can get one from a wrecking yard, but have decided not to. Both of these solenoids are working, the TAD just not working for the correct amount of time it should.
Haynes say to bring motor to operating temp., start the motor and then time the vaccum at the TAD. Should have vaccum for 100 to 300 seconds... mine has vaccum for 15 seconds. This vaccum diverts the air from smog pump to the heads for startup, after which time the vaccum shuts off and the pumped air is defaulted downstream to the CAT converter. Tried the same test from a cold startup, and the TAD held vaccum for 90 seconds. My TAB seems to be working correctly..... when the operating temp gets too hot from idling, the vaccum shuts off and dumps the smog pump air to keep the exhaust system from getting too hot. But still I'm getting code 44r. Only thing I can try next is pull KOER codes with the engine a little cooler. Kind of strange I'm not getting any memory codes.

 

Those solenoid valves are electrically-controlled by the EEC, so test the wiring to make sure you don't have a dirty connector. Timing the vacuum is 2 levels removed from what you should be testing, which is the time that the EEC energizes the solenoid. Use a multimeter.

 

OK, thanks for the reply. Ya, I've been checking for dirty wire connections. In the meantime I have re-adjusted my TPS (again).
This time without moving the Throttle stop screw. Had 1.17 VDC before and changed it to .995 VDC. WOT is 4.75 VDC. Seems to be running better. Had the TPS on backwards from what they say in the manual, but I don't see why that would matter. But now my AOD tranny is shifting later so I'm going to check out that TV cable. Throttle stop is the same. Might have to re-adjust on the tranny. Just shifting a hair late. Gonna check the codes again and see what is up.

 

OK, fixed the TV cable, I didn't have it on correctly. Tranny shifting back to normal.

Now, back to the TAB and TAD. I checked the voltage to the TAB connector, KOEO and got the greater than 10.5 volts. Then plugged it back in and stuck jumper pins in and checked voltage again KOEO ,10.5 volts. Then started the truck (hot)and let it idle (14 volts). After a few minutes the voltage dropped to 0 volts, shutting off vaccum at the TAB, thus dumping air at the Air Bypass Valve. I think this is normal.


I then checked the voltage at the TAD connector, unplugged like before and KOEO and got the greater than 10.5 volts. Then plugged the connector back in to the TAD and stuck jumper pins in and checked the voltage KOEO. Could not get any voltage. Thought the jumper pins were not connecting and tried many times to get a voltage this way, but could not. Couldn't get any voltage KOER with the connector plugged in, but when unplugging it and just checking the connector I got 14 volts. Now I'm thinking there is something wrong with this solenoid. Ford doesn't make it anymore put they said it's a common part number from all 86-87 (S Density EEC-IV) cars and trucks like Crown Vic etc.

 

Well, I got a TAD/TAB solenoid at the junk yard and put it on. Still Code 44r.
Now I'm thinking it's the computer.

 

Well, after scratching my brain for a while, I looked and found 2 vacum leaks, one at the IAC and the other coming off the main vacum tree. I fixed these and then reset my throttle stop screw down to where I got the death idle with the IAC unplugged. Then reset my TPS to 1 volt. Checked the codes again and did not get the 44r, but instead got 41r- Hego low voltage-system lean. Next day checked the codes again.....no 41r.......back to 44r. So? New oxygen senor? I'm going to try one more time checking the codes. This time I'm going to disconnect the battery first. Anybody?