WOT operation?

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 4, 2010

#1

• Jan 4, 2010

• #1

I am trying to figure what the computer does when you push the pedal in (WOT). Car runs perfect under normal conditions but when in WOT the car seems bogged down til 3K. I would think even with the stall converter I should be able to smoke the tires. I get code 11 on both the koeo and koer.

 

1993SSP

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Sep 5, 2001

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Jan 5, 2010

#2

• Jan 5, 2010

• #2

I had the same problem, my TPS was toast. The car would run good with normal driving but when I was at WOT it would just bog down. Make sure you unhook the battery for at least 15 min while you change the tps, when you hook it back up make sure to set the voltage

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 5, 2010

#3

• Jan 5, 2010

• #3

I put a new tps on about a month ago and reset the voltage to 1.0 volts. I have an electrical short somewhere just I haven't had the time to find it so I disconnect the ground at night. I don't drive a lot just once or twice a week at 20 miles a day. If it stays hooked up for more than two day without me driving it will kill the battery, you can even charge it. The other thing I noticed when I was driving at last night was at about 2k I hear a whining sound by the glove box. I was going to check out the reserve tank and vacuum lines over there. I just replaced the major vacuum lines with silcone ones but haven't checked all of them.

 

HISSIN50

"How long does it take to get help in here?

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Nov 29, 1999

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Jan 5, 2010

#4

• Jan 5, 2010

• #4

At WOT, the EGR and AIR are not used and O2's are basically ignored.

 

8

885.0conv

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Phoenix, Az

Jan 6, 2010

#5

• Jan 6, 2010

• #5

When I checked the vacuum lines I found a leak in the line going to the vacuum reserve tank. I didn't get to test since it was late and my neighbors get mad when I start the car late. I also noticed when the car first start up the brakes take both feet stop the car and when the car warms up the brakes are fine. I was reading that be caused due to low vacuum by not having the reserve tank.

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 7, 2010

#6

• Jan 7, 2010

• #6

So after replacing the leaky line my brakes are better and my accerlation is better but still the lag at WOT. My TPS goes from 1.0 to 4.73 in a smooth curve. Does the computer tell the fuel pump to increase? Maybe I have a weak pump? I am not able to look at fuel pressure when driving. My sending unit is bad so I might just change the pump too.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jan 7, 2010

#7

• Jan 7, 2010

• #7

885.0conv said:

Does the computer tell the fuel pump to increase?

Click to expand...

The increase in FP is via a mechanical fuel pressure regulator (it uses a manifold vacuum signal to increase pressure).

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Jan 7, 2010

#8

• Jan 7, 2010

• #8

HISSIN50 said:

At WOT, the EGR and AIR are not used and O2's are basically ignored.

Click to expand...

I beleive the 02's are also ignored over 3K RPM as well

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 7, 2010

#9

• Jan 7, 2010

• #9

I was getting the code for both banks running lean so I replaced both o2 sensors about a month ago and the codes have not been back since. I do remember the car running fine til I went to do the oil pan gasket and timing cover gasket. Maybe I pulled a wire, is there a major thing that stands out in the wiring I can check.

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Jan 7, 2010

#10

• Jan 7, 2010

• #10

Make sure the O2 sensor harness is hooked up. The connection is under the airbox where the MAF would be.

If it is hooked up, just a hunch, but disconnect both o2's (from below the car) and take the car for a ride. If it runs better, then this is a common problem.

Not sure on the fix however as most guys who have had this issue just leave them disconnected instead of troubleshooting further. I wouldn't do that, but i have a hunch this is o2 related

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 7, 2010

#11

• Jan 7, 2010

• #11

Yes the connector is plugged in below the MAF. I disconnected the o2 sensors and there was a little better acceleration but nothing like smoking the tires. The other thing I though of is if the injectors are clogged would that cause the hesitation.

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 8, 2010

#12

• Jan 8, 2010

• #12

After reading the surging idle checklist something just hit when I bought the new TB I don't remember setting the idle screw. (Feel like a DUMASS now). I guess I was just so excited about get a new one I forgot. In the morning the car will start then almost die and then go high and then almost die then it come back to normal after it warms up. I bet this is my problem when I get a chance I will use the checklist to set the idle and let you know what happens.

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 9, 2010

#13

• Jan 9, 2010

• #13

Ok so I set the idle, it was at 800 with the IAC and SPOUT out so I adjusted it down to the 600 rpm mark. I then set the TPS and left the battery unhooked for 10-15 min to reset the computer. At 1/2 throttle the accerlation is really smooth now but at WOT it still seems like it gets bogged down. Now this only happen from a complete stop if I am crusing down the highway and floor it the tranny will down shift and take off. But when it downshift it is always about 3k. So from what I can see the TPS is working because the computer knows when I floor at crusing speeds just not at complete stop. Also there is slight whine coming from the glove box area at about 1500 no matter what gear the tranny is in. I also think something is going on with my ten pin connectors when I do the cylinder balance test I get different cylinders each time I do it. I had autozone check the TFI module and the said it was good. About the only thing left I haven't changed is the distributor. The other question is with this setup is it normal not to have any power under 3k and when you hit 3k you feel the power increase. If that is the case will going to 4.10 gears bring the power down to the 1k-1.5k range.

 

8

885.0conv

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Jan 9, 2008

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Phoenix, Az

Jan 11, 2010

#14

• Jan 11, 2010

• #14

I am 99.9% sure I have found the problem. I was reading some other post and saw that you are supposed to retorque the lower intake bolts to the heads. That is the first I have heard of that. So I took of the upper off and went to retorque, there were some bolts that weren't even at 5 ft/lbs. The worst thing thought one of the bolts spun on me. After taking the lower off, getting new gasket and getting a longer bolt I put the lower back on. I ran out of time today but tomorrow I need to set the dizzy and drive around.