You're a wonderful human being. Thank you.
Here's a link to the fault codes:
A problem with the throttle position sensor itself will not cause the engine to stall. Also, they have a very low failure rate. It is more likely the wires going to it have a problem, and some of those wires have other sensors in common that COULD cause a no-start. Also, just to point something out, there is always a long list of conditions that must be met to set any fault code, and one of them is that certain other codes can't already be set. That is because the Engine Computer compares the sensors to each other and various operating conditions. If a code is set for a sensor it uses for comparison, it knows it can't rely on that so it suspends some self-tests.
A perfect example is the coolant temperature sensor and the intake air temperature sensor. The computer knows those two had better be reading the same temperature after the engine has been off for more than six hours. When they read wildly different temperatures at engine start-up, it may be able to figure out which one is wrong. However, if either one is disconnected, there is a circuit that forces the signal voltage to go high or low enough to trigger a fault code. At that point, the computer can't use it as a reference for the second sensor, so a code will not be set for that one if it is just out of range. The second one can only set a code if it is unplugged too.
I wanted to mention that because sometimes those codes are all a mechanic has to go on when looking for the cause of intermittent problems, and once one is fixed and the code is erased, another code will suddenly appear. The computer is able to resume the self-tests and that's when the next code shows up.
The good news is the throttle position sensor circuit is real easy to diagnose. The hope is the fault is there all the time so it can be found. The computer will detect intermittent glitches too but those make the diagnosis more difficult.
The TPs has three wires. You must take the readings with the plug still connected. You can poke a pin through the rubber seals around each wire and use that with your voltmeter. Start with the middle wire. The ignition switch must be on. The voltage must be within approximately 0.5 to 4.5 volts. 0.5 volts is at idle / closed throttle. At wide-open-throttle you'll find around 4.2 to 4.5 volts. It's when that voltage goes outside that range that tells the computer to set a code. As you can see, the codes for '95 and older vehicles don't get real specific. Code 24 doesn't specify if the voltage is high or low, just that it's wrong. The voltage reading will tell you which.
If you do find around 0.5 volts at closed throttle, the other two wires have to be okay, and the sensor is working properly, at least at this moment. The other two wires are the 5.0 volt supply and the ground wire which will actually have 0.2 volts. If you find the full 5.0 volts on that signal wire, the ground wire is broken, (or the sensor is broken internally). If you find 0.2 volts, the 5.0 volt supply wire is broken, (or the sensor is broken internally).
Before we get too involved, measure that voltage, then we'll figure out where to go next. The 5.0 volt feed wire and the ground wire are in common with a few other sensors that CAN all set fault codes at the same time, and if either of those wires breaks, you'll have multiple codes at the same time. Since there aren't multiple codes, I'm betting the wires are okay.
Measure that voltage and holler back with what you find. Don't use a test light because it will load the circuit down resulting in a false reading.
Excuse me, madmike1735, for butting into the conversation with my first reply. As you can see, I type long replies, and I don't see when someone else has already posted a reply while I'm still typing.
Tuesday, October 1st, 2013 AT 10:57 PM