Throttle body

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#1

• Jan 8, 2006

• #1

Hey I'm trying to install a Edelbrock 70 mm throttlebody on my 87 gt. Its mostly stock with gt40 heads, flowmasters, and 24s injectors. I know 24s are a little much for my setup but I needed injectors and I gottem cheap. Anyways, my question is how do I setup the tps and idle screw? Right now its surging. It comes and goes. Sometimes I can hear some hissing like its got a vac leak someplace but I can't locate it. Its only done that since i put this other throttle body on. Sprayed oil around the area with no effect. Maybe it just breathes differently. I've adjusted the tps from .90 up to 1.10. Anyone got some ideas?

 

2

2002BLGT

Well-Known Member

Dec 18, 2003

2,945

4

59

Bedford VA

Jan 8, 2006

#2

• Jan 8, 2006

• #2

stang0f87 said:

Hey I'm trying to install a Edelbrock 70 mm throttlebody on my 87 gt. Its mostly stock with gt40 heads, flowmasters, and 24s injectors. I know 24s are a little much for my setup but I needed injectors and I gottem cheap. Anyways, my question is how do I setup the tps and idle screw? Right now its surging. It comes and goes. Sometimes I can hear some hissing like its got a vac leak someplace but I can't locate it. Its only done that since i put this other throttle body on. Sprayed oil around the area with no effect. Maybe it just breathes differently. I've adjusted the tps from .90 up to 1.10. Anyone got some ideas?

Click to expand...

you need to take the injectors out and put the 19s back in and set the TPS between .92-.99

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#3

• Jan 8, 2006

• #3

Might could try that. Injectors shouldn't be a problem though should it. I've got a c&f meter thats calibrated for 24s. What bout the idle screw? Any ideas would be most welcome.

 

bock

Founding Member

Jan 7, 2002

648

2

19

Montreal,Qc

Jan 8, 2006

#4

• Jan 8, 2006

• #4

well the idle should be around 750rpm. adjust the screw with the engine running and hot.

for the surgin idle, maybe clean de maf, with a q-tip and alcool.

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#5

• Jan 8, 2006

• #5

haven't done that in a while. i'll try that. i've read that brake clean works good for that too. has anyone tried putting a bigger throttle body on a basically stock setup?

 

1

1SLO306

My 97 GTP owns you ALL!

Mar 31, 2005

904

1

17

Muhlenberg, ky

Jan 8, 2006

#6

• Jan 8, 2006

• #6

wont help u much until u get the other supporting mods

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#7

• Jan 8, 2006

• #7

well i was gonna wait till i build my 347 to do it but my stocker is going bad. butterfly is sticking. just wore out i guess due to wear. hate to pay for a stock throttle body when i've got this brand new 70 mm edelbrock just sitting in my garage. would really like to make this work for now. any more thoughts?

 

bock

Founding Member

Jan 7, 2002

648

2

19

Montreal,Qc

Jan 8, 2006

#8

• Jan 8, 2006

• #8

install the 70mm... you wont have any trouble.you wont have any gain.maybe a lost in power.... but not much...

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#9

• Jan 8, 2006

• #9

i checked the plugs and they actually looked ok. it would have been simpler if they were extremelly lean or rich. that would at least give me a clue. i'll clean the maf. perhaps i'll try dropping the tps down a little. i've heard whats supposed to happen is adjust idle screw till it makes contact. then use 10/1000s feeler gauge plus quarter turn. then adjust tps from .95-1.05 i'm thinkin. thats what i originally tried anyways.

 

Black1987Stang

Active Member

Aug 22, 2004

1,422

0

37

Jersey Shore

Jan 8, 2006

#10

• Jan 8, 2006

• #10

Did u take the intake off to change the throttle body, if so one of the vacuum lines are probably leaking. If you have a vacuum leak THAT could be causing your surging problem, the tps should be set at .98 volts a little under is ok but def. dont go over 1 volt. Try pulling some codes, BTW when my maf was bad it was surging really bad like i had a huge cam in it

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#11

• Jan 8, 2006

• #11

no i left the intake on when i installed it. thats the part that kind of confused me. as best i can see, all the hoses are accounted for so i'm totally unsure where the hissing comes from. it seems to be intermitent too which is weird.

 

P

PRO50SC

New Member

Dec 28, 2003

1,012

1

0

Olney, Maryland

Jan 8, 2006

#12

• Jan 8, 2006

• #12

If you can hear hissing, most likely there is a vacum leak which in turn can cause an idle problem. Unless it's the new t/b making the noise. You need to try and determine the location of the noise/leak.


Good luck.

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#13

• Jan 8, 2006

• #13

sounds like its coming from the throttle body area. maybe it just breathes different with the stock setup. i sprayed oil in the area but that didn't change the idle

 

P

PRO50SC

New Member

Dec 28, 2003

1,012

1

0

Olney, Maryland

Jan 8, 2006

#14

• Jan 8, 2006

• #14

Why would you be spraying oil on the areas? Use carb cleaner spray. The oil just makes a mess.

 

S

stang0f87

Member

Aug 16, 2004

102

0

16

Fort Smith, AR

Jan 8, 2006

#15

• Jan 8, 2006

• #15

true but its not flammable. i don't mind the mess

 

P

PRO50SC

New Member

Dec 28, 2003

1,012

1

0

Olney, Maryland

Jan 8, 2006

#16

• Jan 8, 2006

• #16

stang0f87 said:

true but its not flammable. i don't mind the mess

Click to expand...

 

Black1987Stang

Active Member

Aug 22, 2004

1,422

0

37

Jersey Shore

Jan 8, 2006

#17

• Jan 8, 2006

• #17

is it just me or is that Clown ad up top really pissing you off too

 

vristang

15 Year Member

Mar 31, 2005

4,933

101

124

Seattle

Jan 9, 2006

#18

• Jan 9, 2006

• #18

The reason Starting Fluid works for finding vac leaks is that it is Flammable. unless you spray directly on the headers, or allow large pools to gather on the lower intake, this is not a big risk. Using oil is useless.

The larger/aftermarket TBs are notorious for the whistling that you describe.

I always use brake cleaner when cleaning the maf. First reason, it dries with NO residue. Second, I do not have to make contact with the delicate wires with a Q-tip.

With the couple of vac leaks I have had, I have yet to experience surging idle. I have had the idle surge due to a bad tps, dirty maf, and dirty iac. My vac leaks have always produced a high idle (but consistent), and very poor fuel economy.

just my experiences
jason