Acceleration problems

[Jessestockler]

I have a 93 Ford Taurus SHO and it's having throttle problems. When I'm going down the interstate my car loses power and I have to pump the gas pedal to get it back. Also when I push the gas pedal I have to do it very slowly.I've changed a few things on it already like spark plugs and wires, valve gaskets, thermostat, and both O2 sensors, and fuel filter. Please help!

 

[rubydist]

first, pull the codes. there are instructions here, and all you have to be able to do is connect a paperclip to the right place and count to 9.

there are several possible causes for your symptoms, including bad mafs, tps, iat, etc. that is why you need to pull codes so you are not guessing.

 

[Jessestockler]

The codes I got were 172, 411, 225, 536 while the car was running, then I did it again and I got 172, and 536.

 

[Jessestockler]

The koeo test I got 121,172,176,181,189,214,542!!!!!! Really needing help experts!!! I got a 551 also.

 

[zoomlater]

http://web.archive.org/web/20090429123516/http://www.shophoenixproject.com/eec/code3.htm

Use this to see what the codes are showing. Next you can type the code number into the search function to see what they mean and how to fix them (or ignore them)
Looks like you have oxygen sensor codes, throttle position sensor code, and a cam position sensor code.

 

[rubydist]

121 says the tps is bad. that will cause symptoms you describe
172 is lean on right bank
176 is lean on left bank. the oxy sensor codes could be because the tps is bad and there is more air than the pcm thinks, or could be that the oxy sensors are bad. you need to fix the tps first, reset the codes and then see if these come back.
181 is adaptive fuel rich limit reached on right bank - that will go away after the above codes are resolved.
189 is adaptive fuel rich limit reached on left bank - ditto above.
214 is cid circuit failure - that is cam sensor circuit. does the tach work? is the car hard to get started? if no problems there, ignore for now.
542 is fuel pump secondary failure - that gets set every time the engine stalls and can be ignored.
551 is ias circuit failure - you should worry about the low number codes first and after they are all taken care of, see if this still appears and then deal with it.

 

[Mike Kelly]

I may have missed it. Did you clear the codes after changing the sensors and start fresh with the codes? Mike

 

[Jessestockler]

Actually I have not cleared any codes becuase I didn't know I needed to. Do it after every sensor change? Starts up perfect every time. The tps has already been changed and still problems, forgot to mention above. Tach? Sorry, greenhorn here. But thank you rubydist for the info, couldn't find it myself. And thank you mike I will reset codes when I get home. Easiest way? Thank again guys life savers!

 

[Mike Kelly]

I don't have the links on the cell others may have it handy. Disconnect the battery for a bit is one way.

 

[rubydist]

easiest way to reset codes is to disconnect your paperclip while the codes are still flashing.

tach = the rpm gauge

reset the codes and drive it a couple days, then pull codes again. there may be old codes in there confusing us all. (we are easily confused...)

 

[Jessestockler]

The rpm gauge works. I reset codes yesterday. I'm driving it now and still stalling about 10-15 mph often with cel turning on and off every 10-15 seconds.

 

[rubydist]

ok, so read and post codes tonight for us.

 

[Jessestockler]

Ok.

 

[Jessestockler]

So here's what I got. KOEO - 551, 172, 176. KOER - 172, 411, 536. Plz help!

 

[SHOdded]

http://web.archive.org/web/20090429123516/http://www.shophoenixproject.com/eec/code3.htm

 

[rubydist]

551 = ias circuit failure or (O) No power to PCM pin 1 or bad PCM (processor)
172 = lean on right bank
176 = lean on left bank
411 = cannot control rpm during low idle portion of test
536 = boo circuit failure

It is about 50-50 that the pcm is bad, or else the circuit to the idle air solenoid is bad.

Either you have a significant vacuum leak, or both oxy sensors are bad.

The boo fault may just have been that you did not press the brake pedal at the right time during the test.

 

[Jessestockler]

What should I look for on the circuit to the idle air seloniod? Should I just change the PCM? I'm sure I have a vacuum leak then because I have already changed my O2 sensors a couple weeks ago. Which hoses should I look at first? And also when should I have pressed the brake during the test?

 

[sperold]

Take a hand held propane torch and crack the valve to hear the hiss. Move the nozzle into all the areas that you think you have a leak for a very short period of time. If you have a vacuum leak, the engine will speed up immediately. Be precise in aiming your torch nozzle and allow time to pass between each "stab" into the zone you are interested in.

 

[rubydist]

look if there is power on pin 1 on the pcm or not.

the vacuum hoses are 20 years old, so they are all suspect.

there is a thread on here that tells you how to correctly run the koer test.