I am stumped

[charlesw6954]

i first had a problem then pulled the codes and then replaced the o2 sensors because thats basically what the codes said they were (codes were 91 41 11).
the only thing that did was give the car more power, but didnt fix the problem. i then replaced the tps sensor today and that didnt help so what could be wrong.

the problem is when i am driving the engine is reving then stops then starts reving again.

on one of my o2 sensors i had to wire it because the female connecter is missing were the o2 sensor connects to. do you think i didnt wire it correctly. i belive i did but i could check.

 

[charlesw6954]

ok i went out and checked the wiring and saw that there was (on the left side) 2 black with green stripes. on the passenger side there is white, black with red stripe, then black with green stripe. what i did was switched the black wire from the sensor that was on one of the black with green stripes to the other black with green stripe. anyone get it?

 

[88stangmangt]

on my 87 lx i had long tube header's and i extended the o2 wires my self they came out all the time they caught everthing some times i rode for a day or so without o2 sensors never had jumping idle. i had that on my gt when i first bought it put in some fuel injector cleaner/gas treatment and some stp throttle body cleaner and rarely does it every do it anymore. (use to go from 1k to 500) if that doesnt work for you try to replace your plugs wires and coil. is it mass air?

 

[charlesw6954]

i have brand new plugs, wires, coil, and cap. i have good idle. its that the problem only happens when i step into the gas while im in gear it kinda sputters.

 

[charlesw6954]

i just called a fellow stang and he said in his dads ranger it had the same problem and went out and bought new plug wires and fixed the problem. well i got those cheap 20 dollar oreilly wires. so is that the problem?

 

[88stangmangt]

could be a nice set of wires wont hurt. how many miles on the car? dirty injectors and throttle body can cause bad fuel milage,loss of power,and hesitation.(do you have a aftermarket ignition?) ooh and bad idle i would start there and re-place the o2 sensors too. all these things have to be re-placed around 100,000 or so. this is what i would try first before i dig deeper (you would be surprised how much hp shot igniton wires,dirty injectors/throttle body and bad o2 sensors would cost you just my .02

 

[charlesw6954]

i have replaced the o2 sensors, replaced the tps sensor, but ill put some cleaner in for the injectors. ill also buy some tb cleaner. the engine has 140k. no about the aftermarket ignition.

 

[NKau]

Probably wouldn't hurt to replace the fuel filter while you're doing the other maintenance stuff. You'd be surprised how often those things cause trouble.

 

[jrichker]

Cheap and easy things to do...

1.) Remove the MAF element and spray it with electric contact cleaner or non flammable brake parts cleaner (same thing , just a bigger can and cheaper too).

2. Check the TPS voltage - should be .90-.97. Use a Digital voltmeter to measure the voltage. If the TPS has more than 150K miles on it, replace it.

Here’s a TPS tip I got from another stangnetter…

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better.

(copied from MustangMax, Glendale AZ)

1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.


NoGo50
Super Stanger

 

[charlesw6954]

i replaced the tps but ill check the voltage. this is the reason i say go carb'eds

 

[5.0Droptop]

91 (R, M) System running lean - Fuel control
41 (R) System lean - Fuel control
(M) System was lean for 15 seconds or more (no HO2S switching) - Fuel control

Looks like you are starving for fuel check your fuel press and see if its low maybe you fuel press reg has gone bad.