PLEASE HELP -- No Power

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Fatpolish

New Member

Oct 29, 2006

21

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Sep 25, 2007

#1

• Sep 25, 2007

• #1

Just replaced intake manifold with the one from summit racing. This is for a 98 mustang gt. The orginal one cracked (imagine that). We just got the replacement one with the aluminum front. While doing the swap, we changed plugs and wires. Everything was plugged in, double and triple checked, but now, we have no power when accelerating. It runs nice at a standstill, very responsive, and smooth. We hooked it up to a solas computer and it didn't pull any codes. Don't have a check engine light on. Cleaned MAF sensor.... Now... don't know what to do.. NO POWER!@$$#$! please help!!!
Thank you

Evan

 

04GTMustang

New Member

Feb 28, 2006

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Stafford

Sep 25, 2007

#2

• Sep 25, 2007

• #2

try disconnecting the battery to allow the computer to relearn everything faster. dunno if that will help but it might.

u also might have a slight vac leak somewhere to. u wont throw a code for a lil while either until the computer tries to add fuel to correct it then it throws a lean code. so a code could pop up after about 10 miles or so of driving. but check all vac. hoses.

 

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Fatpolish

New Member

Oct 29, 2006

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Sep 25, 2007

#3

• Sep 25, 2007

• #3

did that... even let it sit overnight. maybe i should use different plugs? I just used bosche plugs... nothing special... and kragen said they didn't need to be gapped.... i don't know... frustrated....

 

96GTstang46

New Member

Nov 20, 2006

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Seattle, Washington

Sep 25, 2007

#4

• Sep 25, 2007

• #4

Well i had the same issue. It was a FAT vacuum leak on mine thoe. It didnt sound just right, but i took some brake cleaner and lighty sprayed it on the motor while it was running, and the motor would rev up. Meaning vacuum leak. It it ran ok, but at WOT it was choke and it felt like a fat pig. (Or a stock Honda witch might be worse )

But just to cover everything, have you ever done a intake manifold before? But i would gap the plugs. .054 I think is correct. Please correct me if I am wrong.

I know you checked everything, but sometimes its the one thing that you know you checked but didnt see it the 1st time?!?! Also check for fuel. Maybe there was some way that not all the injectors are in the rail totally correctly..

Well i know this is a long write up, but just tryin to help. Please repost with any other info. Or better yet, you can post a few pics, to try and help?! good luck

 

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Fatpolish

New Member

Oct 29, 2006

21

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Sep 25, 2007

#5

• Sep 25, 2007

• #5

I'll try to get some pics on later. I'll chk the plug gap after work. And.. it does have a deeper sound... i don't know if that's because new intake or what.. but it does sound a bit more throuty (sp) lets see... hrm..... we've driven it about 30 miles... maybe more... it drives... smooth... it just doens't have any power. Like the computer doesn't know to give it air or fuel... weird.. doesn't bog down or anything, just.. when I go WOT at like 2500 rpm.. it doesn't throw you back in the seat like it use too. could plugs do that?!? and we double checked the injectors to make sure they were properlly set. where are some vac lines that i should check? And thank you for the help!

 

blkhorse

Founding Member

Oct 30, 1999

345

1

18

Sep 25, 2007

#6

• Sep 25, 2007

• #6

at work we have had lot's of running issues with modular ford's and bosch plugs,4.6l,5.4l and v-10's. try changing to a different plug. it got to be such a problem we will not install bosch in any of our fords( I am a mechanic for a large public utility)

 

smokin00GT

New Member

Mar 22, 2007

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United States

Sep 25, 2007

#7

• Sep 25, 2007

• #7

we always use motorcraft plugs in our stangs with no problems.

 

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Fatpolish

New Member

Oct 29, 2006

21

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Oct 25, 2007

#8

• Oct 25, 2007

• #8

So, the car has been to shop twice... changed plugs to autolites. Changed MAF, changed charge air temp sensor. All data being pulled from the computer is saying everything is working fine and the numbers are all correct. The car still has no power, espeicially over 3 grand. Next idea that I was thinking, could it be clogged cats? Maybe we got a lot of fluid and oil in the chamber, and when we started it up, it burned out or clogged up the cats. Any other ideas??

The shop checked for vac leaks and everything was fine. Also, the gas milage or horrible.. around 13 mpg. And, we have popped a hose off the EGR valve a couple times while driving it at WOT. PLEASE HELP!#$! Ford shop here is stumped also.....

 

blkhorse

Founding Member

Oct 30, 1999

345

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Oct 25, 2007

#9

• Oct 25, 2007

• #9

yes,clogged cats can cause that,I would have thought the shop checked the backpressure already....it's not hard to do.

 

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Fatpolish

New Member

Oct 29, 2006

21

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Oct 25, 2007

#10

• Oct 25, 2007

• #10

with clogged cats.... would it effect the performance even out of gear? For exmaple, when i'm stopped, and hold clutch in, I can rev the car and it seems to run fine. It only has no power when it's under load. Is that normal? I'm guessing that clogged cats would only make a huge difference under load. Any help would be useful.. Thank you once again!

 

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travelling frog

New Member

Feb 2, 2003

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Oxford, MA

Oct 25, 2007

#11

• Oct 25, 2007

• #11

When you say the numbers are correct, what is the Air/Fuel ratio doing? Couldn't horrible gas milage could mean it's running really rich.

 

blkhorse

Founding Member

Oct 30, 1999

345

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Oct 25, 2007

#12

• Oct 25, 2007

• #12

Fatpolish said:

with clogged cats.... would it effect the performance even out of gear? For exmaple, when i'm stopped, and hold clutch in, I can rev the car and it seems to run fine. It only has no power when it's under load. Is that normal? I'm guessing that clogged cats would only make a huge difference under load. Any help would be useful.. Thank you once again!

Click to expand...

dpending how bad they are plugged they can effect no load,but i have only seen them go that far A few times,I would for sure check your back pressure. this would be my next check

 

tomustang

Psychotic Member

Founding Member

Jun 8, 2000

3,434

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78

McLean Hospital

Oct 25, 2007

#13

• Oct 25, 2007

• #13

Fatpolish said:

but now, we have no power when accelerating.

Click to expand...

Can you elaborate Mr Fatpolish?

 

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Fatpolish

New Member

Oct 29, 2006

21

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Oct 26, 2007

#14

• Oct 26, 2007

• #14

tomustang said:

Can you elaborate Mr Fatpolish?

Click to expand...

Um.... very sluggish.... vveerrrryyyy ssllluuugggiiissshhhh it's a weird feeling slamming 4k rpm and not going very fast. What cats should i get? was looking at the BBK off of summitracing. Any other ideas? and we've got dual flow's on it already... and I'm in CA so i need the cats...

 

blkhorse

Founding Member

Oct 30, 1999

345

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Oct 26, 2007

#15

• Oct 26, 2007

• #15

check your back pressure first and if their plugged then replace them,no sense on just throwing parts at it if you don't have to

 

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Fatpolish

New Member

Oct 29, 2006

21

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Oct 26, 2007

#16

• Oct 26, 2007

• #16

ok... going to buy a gauge to do it. Also, if i were to get the catted BBK Extractor Series from summit racing... would I need the MIL Eliminator kit? any help would be great! Thanks! And I'll post my readings from my back pressure tests.

 

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Fatpolish

New Member

Oct 29, 2006

21

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Oct 27, 2007

#17

• Oct 27, 2007

• #17

So I went ahead and ordered the BBK x pipe with cats... hopefully this will help.... the back pressure test wasn't that helpful...
because it doesn't measure the engine under load.. any hints on the install of the x-pipe? anything i need to know?