1995 Ford 3.8L Sluggish when warm.

Quick question, what would cause my 1995 F.T 3.8L Automatic 96K miles to feel sluggish when warm? Not even like sluggish, because if you give 100% throttle, the car is fast, and acts 100% normal. When the car is cold, It runs great, and will run great for the whole trip 25+ miles one way, but it seems as when you turn off the car and restart it, then it runs sluggish right from there. Is there any sensors that i can clean/check/replace?

Give 100% throttle, and you can spin tires.

If you give 75% throttle, the car will rev high, and it feels as if i lost 4 cylinders.

Give it 50% throttle, and the car will almost be faster then giving 75%, then if you letup to 25%, The car then feels the fastest out of the 3..

Does not happen all the time, It is totally temperature dependent. 70F+, City driving makes it seem the worse.

Transmission is perfect, Just changed fluid and filter twice.

I use Pennzoil Platinum 5W30 and a Fl-400s Filter.

Ran cleaner with the gas.

Thanks!

When it's sluggish, is it still smooth or does the engine seem to be misfiring? Have you changed the plugs, wires, and fuel filter recently?

-Rod

When it's sluggish, is it still smooth or does the engine seem to be misfiring? Have you changed the plugs, wires, and fuel filter recently?

-Rod

It does not seem to be a misfire, or anything like that. The car still runs smooth. I have checked the plugs/wires, they seem pretty new..

It seems as when its pretty warm,(City driving) you have a extra 800 LBS that you are pulling. Then if you floor it, It flys, and is 100% normal, but only floored. As soon as you let even just a little bit off of the gas, you gain back the extra 800 LBS.

The first trip of the morning is the best. The car seems the most responsive, I do not need to give alot of gas to get up to 60 MPH, maybe like 35% max, and i am going 60 pretty quickly. This will last pretty much for the whole trip(30 miles), Then as soon as i shut the car off and restart it, then its like the 800 LBS is with you again. :banghead:
Thanks!

I'd probably start my troubleshooting at the Coolant Temperature Sensor. The CTS tells the Powertrain Control Module (PCM) what the temperature of the coolant is and the PCM adjusts air/fuel ratio and timing accordingly. That's one of the few sensors that I can understand causing significantly different results when cold than hot but still work fine at full throttle, as well as not acting like a misfire at low engine speeds. Keep in mind that the CTS is not the same as the Coolant Temperature Sender which is only used for the instrumentation.

If the CTS doesn't pan out, then I'd look at the oxygen sensors to see if they are responding properly.

-Rod

I'd probably start my troubleshooting at the Coolant Temperature Sensor. The CTS tells the Powertrain Control Module (PCM) what the temperature of the coolant is and the PCM adjusts air/fuel ratio and timing accordingly. That's one of the few sensors that I can understand causing significantly different results when cold than hot but still work fine at full throttle, as well as not acting like a misfire at low engine speeds. Keep in mind that the CTS is not the same as the Coolant Temperature Sender which is only used for the instrumentation.

If the CTS doesn't pan out, then I'd look at the oxygen sensors to see if they are responding properly.

-Rod

Thanks for the reply, I went and checked the CTS, (Should i replace it?) and it was fine. I just gave it a quick clean and put it back in. It was a Motorcraft part, so most likely OEM. The EGR, some one said that if i unplug it, and see if there is any difference, if there is, most likely the EGR valve is sticking open? Would that work? I dont want to ruin anything by running the engine with out the EGR valve. :)

The EGR valve on your Taurus is a vacuum operated, mechanical style. GMs and others use an electronic EGR that has an electrical connector on them, no such luck on Fords. If the EGR is stuck open, you'd have a rough idle because you'd essentially have a vacuum leak. You mentioned the engine idles smoothly.

The CTS is a thermistor, you can't look at it and determine if it is fine. You need to measure the resistance or voltage drop over a range of temperatures to determine if it is working properly. If you decide to just replace it, make sure to replace it with a high quality brass one. Some are now on the market that are mostly plastic and quite a few folks have said they don't last long.

-Rod

I was having the same problems with my 94. So today I replaced the coolant temp sensor and it has shown a great improvement. Sensor didn't look worn at all. However I did throw a code for the sensor.