QuestionQUESTION: i have a 89 ford f150 EFI 302 engine 8 cylinder i keep having code 44 come up on the thermator system could you please give some idea how to fix this situation...i am a diesal mechanic and i still can't figure this out..it keeps failing emissions...thanks
ANSWER: Hey Tagg,
If the truck is not passing emissions, it may not be directly related to that code, but could be also.
What are the readings on the gases it is failing on and what are the limits? All states have different programs, but all are similar in many ways. HC(Hydrocarbons), and CO(carbon monoxide) are the harmful gases that are the basis behind all smog programs. Many more populated areas test for NOx(oxides of nitrogen), which is considered a "greenhouse gas".
If the vehicle is failing for high CO and HC, it's getting too much fuel and causing a misfire in the process. If there is no CO present , or very little, with high HC, there is a misfire, caused by a lean condition or ignition system. When there is a proper balance, it all equals out. Most Ford products of that year fail because the air injection system(air pump system)isn't working properly, or fuel system problems, like high fuel pressure or leaky pressure regulator.
Please get back to me with some numbers on what the truck failed for, and I will research what a code 44 is for, which might be the Air Intake Temperature sensor. That sensor is screwed into the intake and gets carboned up and throws the system way off when it doesn't read properly. I can definitely help you get that beast through emissions. I hope this helps. Shaun.
---------- FOLLOW-UP ----------
QUESTION: code 44 is thermactor air injection system inop. i've done all the proper vacuum,electrical & air pump tests. all check out o.k. the only way to get a test result without code 44 is to apply manual vacuum to the diverter valve. i even tried a different pcm. what sensor inputs are used by the pcm to operate the t.a.d. system? the last e-test results are: rpm-1149:(hc)limit-90 read-375 (co)limit-0.66 read-0.95 (nox)limit-1587 read-1004 dilution-13.7 / rpm-700 curb idle: (hc)limit-200 read-1275 (co)limit-1.00 read-1.25 dilution-10.0
AnswerHey Tagg,
Although getting the air pump working properly will possibly be needed to get it passed, I don't think that is the total cause of your problem from looking at the numbers. I am concentrating on the extremely high HC(hydrocarbon) readings at cruise and curb idle. High HC numbers are caused by an engine misfire, usually caused by the ignition system. If the CO(carbon monoxide) readings were higher, I would suggest it is caused by a rich mixture, but that is not likely the case. If the C0 was 3 percent or more, then a rich condition would be suspected. When the engine is misfiring it puts extra oxygen in the exhaust and throws off the control system, causing C0 numbers to rise slightly over limits. I would say that if you repair the engine misfire(plugs,wires,cap/rotor etc.), you might not even have to address the AIR issue. First check for supply vacuum to the control solenoid for the diverter valve. Those plastic lines crack all over the place, so run a new line if you have to. Also check for leaks in the hose from the solenoid to the valve also.
I hope you can get that thing passed, and feel free to follow up. Good luck. Shaun.
