Car runs great but surges/bucks in 5th at 1300-1500 RPMs

DogVomit

Member

Jun 9, 2005

192

1

19

Tampa, FL

Dec 29, 2005

#1

• Dec 29, 2005

• #1

I can't figure this one out. It runs fine at all RPM's and smooth as could be. But between 1300 RPM's and 1500 RPM's in 5th at a steady speed, it just bucks every now and then. I feel the power drop out for a sec., then it resumes steady running.

The reason the RPM's are low is because this is regular road driving and at 2000 to 2300 RPM's I move from 4th to 5th. My RPM's then drop down to that 1300 to 14/1500 range. Then I can feel it bucking, like it's losing power for a half a second, then resumning power.

Any ideas?

 

timeless2

Vi Veri Veni Versum Vicus Vici

Admin Dude

Nov 29, 1999

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Dec 29, 2005

#2

• Dec 29, 2005

• #2

When was the last time your fuel filter was changed? Your new setup might be thirstier than before.

 

DogVomit

Member

Jun 9, 2005

192

1

19

Tampa, FL

Dec 29, 2005

#3

• Dec 29, 2005

• #3

New filter and plugs about 2 months ago.

 

BaconBits

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Apr 4, 2005

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Dec 30, 2005

#4

• Dec 30, 2005

• #4

That is strange. I have a 2002 that was doing the EXACT same thing. I couldn't figure it out. And I was at that RPM a lot going 50-55 in fifth gear. I was frustrated as hell!!! But I recently put in 4.10's and I very rarely run at that RPM anymore, but I'm sure it's still there. I also am interested in what people have to say about it.
P.S. I changed my fuel filter, plugs, and checked ALL vacuum lines a 100 times and it still did it. My brother thought I should change out my PVC valve, but after I got gears I didn't bother. Maybe try that….

 

timeless2

Vi Veri Veni Versum Vicus Vici

Admin Dude

Nov 29, 1999

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Dec 30, 2005

#5

• Dec 30, 2005

• #5

DogVomit said:

New filter and plugs about 2 months ago.

Click to expand...

MAF cleaned?
Are the cops in good shape?

 

DogVomit

Member

Jun 9, 2005

192

1

19

Tampa, FL

Dec 30, 2005

#6

• Dec 30, 2005

• #6

Glad to know that someone else had a similar problem. Maybe it's not just me.
What gears did you put in? I'm supercharged so I don't want anything outrageous... I smoke the tires too easy as it is

But I'm interested in gears to throw the RPM's up to about 1500 - 1700 in 5th at 50-55. That should do it. Great idea and thanks.

I also haven't checked my MAF, since I'm sure it was done 2 moths ago during the Vortech install.

I'd rather not toss more cash (or plastic) at my stang for gears. But I don't know what else to try. Gears sound like an expensive alternative. But may suffice.

 

Marks5.0!

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Jan 27, 2000

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San Antonio, TX

Dec 30, 2005

#7

• Dec 30, 2005

• #7

prolly a tune issue, i had the same thing in 4th and 5th on 1 of my old tunes.
felt real bad in the 1300-1700 range just cruising. dunno exatecly what my tuner changed but my current tune fixed it and the car now drives better than it ever has

 

DogVomit

Member

Jun 9, 2005

192

1

19

Tampa, FL

Dec 30, 2005

#8

• Dec 30, 2005

• #8

Marks5.0! said:

prolly a tune issue, i had the same thing in 4th and 5th on 1 of my old tunes.
felt real bad in the 1300-1700 range just cruising. dunno exatecly what my tuner changed but my current tune fixed it and the car now drives better than it ever has

Click to expand...

Tunes count. I'm thinking that's the problem.
Looking for another shop for a good dyno-tune.