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Anyone have any experience with Code 133? The truck flashed it to me twice during a KOEO test. That's the only test I can perform since the truck won't start. Haynes manual says 'Heated oxygen sensor slow response'.
Truck struggled to start, but still did about 2 weeks ago. Chugged, started, wanted to die, but stayed alive with the help of the gas pedal. Stayed alive and ran fine if you could get it thru the first minute.
PO133 is an obd II code. There is no 133 for Ford OBD 1. Regardless it sounds like you may have a failing fuel filter or fuel pressure regulator
Some 10 year old info does show a two digit 33 as this. "Continuous Memory Code 33 indicates that the EGR valve did not open with the engine stabilized and with EVR solenoid duty cycle present sometime during vehicle operation". I don't think this should not be applicable to your symptom and your truck has three digit codes I believe. Sandy
Edit if you read from the check engine light you may have had flashes like this: 1 111 1 111. That would mean all clear which would make more sense since you were in KOEO.
1. I've seen other posts where people say that code 133 doesn't exist. Attached picture is from the Haynes manual. Slightly confused.
2. Maybe I read the codes wrong, but if so, it was more like 1 111 111 1 111 111. There were definitely two distinct back to back groupings of three flashes. Idk.
3. Have been leaning toward a fuel delivery issue since the problem started. Car actually started up after my earlier post (likely aided by oddly warm weather), but it died despite my efforts on the gas pedal. Can hear the fuel pump when I turn the key to the on position. Based on the Haynes manual, seems like fuel pressure is the next thing to check?
I referred to my Haynes and it shows the 133 also like yours. Every other source I have shows no 133. Haynes and others are known to have mistakes.
You can rent the Pressure gauge but if you haven't replaced the filter lately I would do that also. If that works for you then you can remove the filter and try to blow through it. If stopped up and you have been hearing the fuel pump run for 1-2 seconds after key on, I think you can forget the pressure gauge and the hassle of renting and returning it. Another option is you can try to start the truck and if it runs and dies or doesn't run, pull the vacuum line off the FPR and if you see gas or smell it, it is probably bad.
" Based on the Haynes manual, seems like fuel pressure is the next thing to check?'"
Even if the Haynes is correct which I doubt because my other sources have been spot on in the past. The symptom they describe that causes the code would not apply to your symptoms. Sandy
Skip renting the pressure testing tool, and check the fuel filter instead? I should be able to pull it and tell if it's stopped up? They're pretty cheap. May just replace since I don't know if it's ever been done.
If the filter isn't the issue, pull the vacuum line off the fpr in an attempt to diagnose if the fpr is the problem?
Skip renting the pressure testing tool, and check the fuel filter instead? I should be able to pull it and tell if it's stopped up? They're pretty cheap. May just replace since I don't know if it's ever been done.
If the filter isn't the issue, pull the vacuum line off the fpr in an attempt to diagnose if the fpr is the problem?
Thanks
Not skip the pressure testing tool just do the others first. Since you should change the filter anyway if old, and it test bad you can skip the FPR test. If the filter is good you then check the FPR test on previous post. When you go to the parts store just get the filter for sure and if the FPR test bad you get it at the same time.
If both parts test good then get the filter and rent the pressure test tool. Bases covered. Sandy
So let's assume I do have some issue in the fuel system somewhere. Why would I not be getting any codes related to that? Can fuel system issues be diagnosed by the computer only when the car is running?
The 1994 F-series truck does not have a 133 code in KOEO, CM or KOER.
However if your truck has a 4.9L engine with a standard transmission then you should have two digit codes.
So let's assume I do have some issue in the fuel system somewhere. Why would I not be getting any codes related to that? Can fuel system issues be diagnosed by the computer only when the car is running?
The DTCs (Codes) are as follows. The KOEO are electrical codes that are checked with the engine not running and are not saved. They check to see if the circuits are open or closed and if the resistance value of items is what it should be for a warm engine.
The CM DTCs are codes that are stored for 80 engine startups and are from when the engine was running. These are stored in memory when you see the MIL (CEL) come on when you are driving or the truck is setting with the engine running. The CM codes are displayed after the KOEO codes are read out twice and then the CM DTCs are read out twice.
The KOER DTCs are actuator tests for moving items (solenoids, and veriable resisters).
Thanks for the background info. However, I still have questions about the potential fuel system issues discussed above. If for example the FPR were bad, should I expect to get a code for it? Please forgive my ignorance, learning as I go.
EDIT: Thought about it some more. Please correct me if I'm wrong. Filter and FPR aren't really electrical items (not items within a circuit, not electrically actuated, etc). So I guess I shouldn't expect any codes if they are clogged/faulty. Something like the fuel pump however, if it were bad (which I don't believe mine is/are), is something that might throw a code?
1994 F250. 5.0L w/ AT.
So should I be seeing two or three digit codes? If two digit, does Code 33 make sense?
The 1994 F250. 5.0L w/ AT would have three digit codes.
The fuel pump will throw a code, if there is an open or short in the pumps windings. The electrical circuit feeding the selected pump will also throw a code if open or shorted to ground.
Note that about 7 VDC with a high impedance meter is normal for the electrical circuit feeding the selected pump with the fuel pump relay open (not picked) or pulled out.
So this circuit should be checked with a loading test light (non LED) for power to the pump. Note also that power will only be on the circuit for one second each time the key is turned to the run position or the PCM receives a PIP pulse.
Note that in these trucks, OBD one and two, there is no device giving fuel pressure readings to the computer so the computer has no way of knowing there is too little or too much fuel pressure for any reason.
So the fact that you don't get a fuel pressure error code doesn't mean you don't have a fuel pressure problem. Only using a fuel pressure gauge will tell you that.
Working on these trucks requires a code reader and a fuel pressure gauge.
