Acceleration goes flat when secondaries open

[shojockey]

I have a 95 SHO ATX, I have replaced several sensors, TPS, IAC, EGR control,02 sensor bank 1, knock sensor. Up until replacing the knock sensor it was the only one kicking out a code, after replacing it it started kicking out the bank 1, 02 sensor again. The engine runs good under moderate exceleration, but as soon as you push it to the floor it fall on it's face.. I'm sure I'm not the first one to encounter this problem. Can anyone give some insight as to what to do? Any help is truly appreciated.

ShoJockey

 

[Slo-Sho]

Fuel filter/pump?

 

[shojockey]

Slow Exceleration

Hi Slo Sho,
The fuel pump and filter were some of the first things replaced when I got the car... Thanks,

ShoJockey

 

[40BelowSummer]

What Codes? Oil in the plug wells? Air leaks? Plugs/Wires?

need for info.

It wouldnt hurt to clean the MAF sensor either.

 

[shojockey]

Slow Exceleration

I just replaced the the valve cover, plug well and intake gaskets along with the knock sensor. Prior to this I't got new plugs and wires when I cleaned the intake and EGR tube.
What is involved with cleaning the MAF sensor?
Thanks,
ShoJockey

 

[betterman]

Yeah I had the same problem until I cleaned the MAF sensor. You'll either have to get a security torx head to get the screws out to get the MAF out of its housing or you you could cut a notch in the screws with a dremel and use a flat head screwdriver to screw them out. When you get the MAF out of its housing you will want to make sure that you don't wreck the small wire that runs between the two prongs. It is very fragile. What I did was spray some electrical contact cleaner on the wires (they are probably covered in black) and then used compressed air to blow the debris off the wires.

 

[sdpatt]

What, exactly, is the O2 sensor code that you are getting? If you have recently replaced the sensors and are still getting a code, the sensor is likely trying to tell you about a problem it is seeing. I'm going to guess that it is a lean code, but telling us the code number is more helpful.

If it is a lean code on one bank and the sensor is new, the problem is probably a vacuum leak. From the performance problems you are seeing, a rather substantial one at that. Bank 1 is the right or rear cylinder bank near the firewall. There are several vacuum connections from that side of the intake. Check them.

The largest is near the passenger side and is the primary vacuum tap for al of the vacuum driven accessories on the car. Near the center of the intake is the secondary runner control's vacuum accumulator tank and solenoid. On thedriver side on your 3.2L is the exhaust gas recirculation valve and flow path. If you had the intake off recently, you should check for each of these connections to be leak free.

 

[F-22 Raptor SHO]

Ditto scott's post, guess I would add one other item: can you verify that the secondaries are actually opening? rev it up under the hood and see if they open. Being you had the intake off, the hoses could be loose, or the electrical connector on the back tank could be disconnected. I have done this before.

 

[shojockey]

Slow Exceleration

Thank you Guys,

I will take the MAF off and clean it, and by the way the O2 sensor I replaced was the wrong one I was told by the fella at the parts store that the #1 bank was at the front side of the car.... talking with one of the mechanics at work, he said "Don the right side is the side closest to the fire wall, or right side if you were sitting behind the engine", Who knew....
Anyway, thanks again. I'm sure it will make a difference.

ShoJockey

 

[projectSHO89]

can you verify that the secondaries are actually opening? rev it up under the hood and see if they open. .

Can't do this on an ATX, the computer won't allow it....

Steve

 

[shojockey]

Slow Exceleration

Fellas,
Thankyou for all you help, as it turned out I had another bad O2 censor and the MAF had dirty wires in it. After taking care of that the car now runs terrific and the other issue I had with the trans shifting had going into 2nd gear has all but gone away.
Thanks Again,
ShoJockey

 

[stevemainian]

My ATX is the same. If you floor the pedal nothing really happens. I honestly think its all controlled by the computer. On the ATX, flooring the pedal seems to only make you go slower. So only depress it about 75% of the way and it seems much more effective for some odd reason.