I had just crossed 188K on the way to work and bucking started out of nowhere. I limped home and at times it seem to run fine then started bucking again. At lred lights it went dead but started right up but bucked and studdered out of the gate.

Ran codes and got '13' Pressure Senor. Seems odd that this would go out as I would think they'd last forever????

90' Vert MTX

 

Last forever? No. Nothing on a car lasts forever. Everything is susceptible to wear and tear, especially a pressure transducer. If I recall, it's a diaphragm attached to a potentiometer, so it does have moving parts. Along with that, because it's pretty much a variable resistor, so it can burn up just like anything else.

Check wiring, check voltages, determine whether it's actually the sensor, or if there's wiring at fault.

 

Ok, thanks. I'm not electrial oriented so I didnt know. I just thought if its that easy to get to it can't be broke. Everything that breaks on me ends up being in hard to get to places.

I'll try the troubleshooting in the FSM. It looks straight forward.

 

one of the fc's i owned would buck like crazy sometimes. turned out to be the tps. you might want to try unplugging the tps before you spend money on anything. just a thought...

 

Code showed '13' so I checked the Pressure Sensor and it seemed to check out. Does this look right on my procedure (I'm not electrical oriented so thats why I ask)?

1) Applied ~4 Hg-mm vacuum to hose connection using Mighty Vac
2) Probe on 'D' connector (Still plugged into press sensor) & ground to shock tower
3) Had Volt meter set on 20 Vdc
4) Turned ignition 'on' without starting car
5) 3.08V. So it looks good

Now in referring to TPS, are you saying 'Sticking' like binding intermittantly??? It seems to push in (plunger) realatively easy.

How common is it ECUs go bad??

 

You might also check the wiring from the pressure sensor to the ECU. If the sensor is ok, it may be that you have an intermittent open or short in the harness. Before you go buying parts, access the ECU (under the passenger's toes), find the pinouts in the FSM and check to see that you have the correct volatage on the pin at the input to the ECU.

Been there, done that.

 

I cant get to the ECU today, but when I do, what should I see when I probe the voltage. I assume I stick the red probe in the connecter where the wires go (each wire in connector I probe?) and ground the other end. Turn switch to 'on' but dont start. Is that the right process??

 

Doing the voltage checks might show a good sensor, but I have found more than a few wiring problems at the pressure sensor connector. With the engine at idle, start wiggling the wiring harness leading to the sensor a few inches at a time. Don't yank the damn thing, just wiggle. Most of the problems I encountered were at the sensor connector, requiring re-soldering or replacing the terminals. You can even narrow down to which wire it is by moving each wire gently with needlenose pliers and watch for engine stumble.

 

I did the wire wiggle, voltage checks and no indications to suggest a problem. But got the '13' code again so I bit the bullet and bought a new pressure sensor. Not 100% sure, but took it for a short drive and checked the codes and no codes. I'll go for a longer drive tomorrow.

I cut the old Pressure Sensor open. Anyone see anything that stands out on why it died?

 

my friends FD overboosts (18psi on the first turbo) and it occasionally throws a 13 code. i think pressure sensor is ok, it just doesnt read that high.