My Taurus Misses At Full Throttle

My 98' Taurus DOHC, The RPM drops at start up but then recovers, When I shift into in Reverse or Drive the idle drops almost about too stall. For about a second it recovers. I did a torque test, in Drive and Reverse. And the car starts too stumble or miss when under a load.

I also noticed that when i'm driving, and I want too pass somebody the car starts too lose power when I put it too the floor. I'm thinkin Clogged or restricted caylatic converters might be the problem.

I've changed:
Spark Plugs
Spark Plug Wires
New Intake Upper Plenum Gaskets
Fuel Filter

Thanks for your help,

Bill

I assume you were having this problem before you changed the plugs and wires? If not, then if you put Bosch plugs in then those could be bad, or the wires may not be installed properly.

I agree that the cats may be toast. Another possibility is a dying fuel pump or injector.

It sounds like you have taken the "shotgun" approach to car repair. Very likely you have replaced a lot of serviceable parts. When I have done this I learned that I was usually entirely WRONG. You getting any indications from the "check engine" light?

Since when are spark plugs, ignition wires, manifold gaskets, and fuel filters serviceable?

Check your vacuum lines

i have put in AUTOLITE spark plugs. Which i heard those were standard for Ford.

I don't have a check engine light. When i get her too the floor she misses for a second and then regains power.

Another thing, i know that my tranny is slowly dieing. She starts too slip when I try too pass on the highway.

Thanks for your help,

bill

i have put in AUTOLITE spark plugs. Which i heard those were standard for Ford.

I don't have a check engine light. When i get her too the floor she misses for a second and then regains power.

Another thing, i know that my tranny is slowly dieing. She starts too slip when I try too pass on the highway.

Thanks for your help,

bill

Motorcraft plugs are original equipment on the Taurus, not Autolite. But Autolites should be just fine.

Yeah slippage is a bad sign generally. All I can recommend is making sure you check your transmission fluid, make sure it's full and in good condition. Beyond that you're probably looking at having a significant repair done. Are you possibly mistaking the misfiring as slippage? Or vice versa?

BTW how many miles on the car?

i have 135,000 miles on my car. I know most all taurus tranny's start too go out past 100,000. The lucas transmission stop leak, seems too work. i do hear an internal hydrailic leak for the transaxle too.

i have 135,000 miles on my car. I know most all taurus tranny's start too go out past 100,000.
Whoa whoa, that's absolutely untrue. While they don't have much of a rep for absurdly long lives, they are nowhere near the worst of the automatic transmissions on the market over the past few years. Many people get well over 200K on their first Taurus transmission.

I will add, though, that in Gen 3 and Gen 4 Taurus (1996+) the majority of serious premature transmission problems seem to occur with your engine, the Duratec. The AX4N comes with all Duratecs and is built slightly better than the AX4S, which comes with almost all Vulcans, but it seems that with all the added torque of the Duratec, those AX4Ns just get a lot of strain.

thanks for your advice sfontain, last night i decided too work on my car. i cleaned the TP sensor, and the MAF sensor thinking that might help the problem, then i was checking the hoses for the fuel regulator and the EGR. everything looked like it was all hooked up. i also checked the connection on the EVAP as well. so i started up my car and i could hear this major leak from the intake. it turns out that the EVAP hose and the fuel regulator hose came together too this rubber connector on the back of the intake. the fuel regulator hose must have popped out. and i think that's why i was getting a "lean miss" at full throttle.

though i still should get my injectors cleaned, i had the fuel rail flushed at college about a year ago.

i also made a statement that my catlyatics coverter are possibly toast. but a friend told me about pre-cats? he told me that if i had them, i can take them out and have more horse power? i dunno if i have them on my taurus model.

i also made a statement that my catlyatics coverter are possibly toast. but a friend told me about pre-cats? he told me that if i had them, i can take them out and have more horse power? i dunno if i have them on my taurus model.
This is true: You can remove them and get more HP, but I believe your check engine light will also come on because of the O2 sensors after your cats generating unexpected inputs. There are ways to handle this but they cost money. Additionally, if your state has emissions testing then you are generally going to fail it.

i did a pressure check on the fuel pump. KOEO it was 30 psi. (but when the pump turned off, it didn't want too hold the pressure.) KOER it read about 35 psi. With the fuel regulator hose off, the pump maxed out at 40 psi. Is my fuel pump shot?

i took apart the upper intake mainfold last night. i quickly found out the the mainfold was full of oil. i think the PCV is sucking oil into the intake.

I don't know if what you mean by slip is the same with a standard transmission, but I thought there is always a momentary pause when you floor it in an automatic, becuase they have to hook up. If I floor mine, the rmps go up and you can hear the engine rev, but it takes a second to get the car going, because the transmission hadnt hooked up. I may have just misunderstood what you meant by slip though.

my first guess would have been a clogged fuel filter then a weak fuel pump. my 97's pump died on the hiway in rush hour, not good when in the middle lane. just died w/o warning.