timing and power

9

95 stang v6

New Member

Oct 11, 2009

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0

Jan 4, 2011

#1

• Jan 4, 2011

• #1

i just recently did a v6 to a v8 swap. the motor is fully rebuilt and has many aftermarket accesories. i dont have o2 sensors or egr. it runs and idles but it just doesnt have the power that it should have. the intake will pop and backfire through the exhaust when laying into it. ive messed with the timing multiple times. it was a tooth off and is doing better. but still wont get the power. could this problem be with having no 02 sensors or could it be that the vaccum is messed up. any suggestions i need power. should i buy a tuner and just tune the computer to run without the o2 and egr or does that not have anything to do with the problem.. help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

HISSIN50

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

15 Year Member

Nov 29, 1999

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Jan 4, 2011

#2

• Jan 4, 2011

• #2

Why doesn't it have O2's?

I'd pull codes and install some O2's and see what happens.

You don't list the mods so no one will know if a tune is really needed. Forcing a constant open loop is not too desirable.

Good luck.

 

9

95 stang v6

New Member

Oct 11, 2009

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0

Jan 4, 2011

#3

• Jan 4, 2011

• #3

o2s arent hooked because there isnt a spot in the down pipes. but it has gt 40p heads and upper and lower bbk headers no cats. 70 mm throttle body with spacer, cai underdrive. flat top pistons roller cam lifters. egr delete fogered internals double roller timing chain. etcc....

 

HISSIN50

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

15 Year Member

Nov 29, 1999

31,179

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Jan 4, 2011

#4

• Jan 4, 2011

• #4

Do you run 24's with a stock MAF and stock GT tune?

 

9

95 stang v6

New Member

Oct 11, 2009

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Jan 4, 2011

#5

• Jan 4, 2011

• #5

24's?

 

HISSIN50

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

15 Year Member

Nov 29, 1999

31,179

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Jan 4, 2011

#6

• Jan 4, 2011

• #6

24 pound injectors. They're the commonly used injector with a Cobra (Gt40 style) intake.

If you have a Cobra EEC, it expects 24's to be used. If you have a GT EEC, it expects 19's.

 

9

95 stang v6

New Member

Oct 11, 2009

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Jan 4, 2011

#7

• Jan 4, 2011

• #7

im running 19's still

 

toyman

10 Year Member

Jul 19, 2007

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Vernon BC

Jan 4, 2011

#8

• Jan 4, 2011

• #8

I would be inclined to weld bungs into the mid pipe and install the O2 sensors. The PCM is programmed to read the O2 sensor voltage output in order to manage many operating parameters. Without that feedback the PCM is operating blind so to speak and may well have defaulted to limp mode. Pulling fault codes is really a must do for any computer controlled system. Otherwise, like the computer you are operating blind as well.

 

revhead347

Apparently my ex-husband made that mistake.

20+ Year Stangneter

Jun 14, 2004

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Acworth, GA

Jan 6, 2011

#9

• Jan 6, 2011

• #9

Always start with what you know is wrong. The computer is designed to run with O2s, so fix that problem first. The timing can't be a tooth off. I'd set your base timing around 10 for starters.

Kurt

 

95opal

5 Year Member

Nov 16, 2004

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Jan 6, 2011

#10

• Jan 6, 2011

• #10

revhead347 said:

Always start with what you know is wrong. The computer is designed to run with O2s, so fix that problem first. The timing can't be a tooth off. I'd set your base timing around 10 for starters.

Kurt

Click to expand...

agreed