i just got my 454 throttle body on, but i am having a few problems.

1 - the idle is a little high. sometimes its higher than other times, but its almost always well over 1,000 rpm.

2 - it sounds likethe "choke" is open all the time. either that, or there is a vacuum leak, but i can't find a leak. (by the choke i mean the "whooshing air" sound that the car is supposed to make at start up, that usually goes away after like 10-20 seconds)

i am not getting any codes for the IAC. could it be an IAC related problem, but not throwing any codes? i just cant figure out why it is acting like this.

now before you guys jump all over me about this, NO i dont have a custom chip. and, NO this dopesnt have to do with that. i had the original 305 and the holley throttle bodies on without problems. (well..without these problems) so i know that this has something to do with the 454 tb, and i just have a feeling that the sound and high idle is because the IAC not functioning correctly.

any suggestions?

thanks guys..

-brian

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1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
10 bolt - SLP zexel torsen differential, GM 3.42s
z28boy.fbody.com
z28boy@twcny.rr.com
AIM - "Z28 Boy"

1998 Pontiac Grand Prix GT - 2 door, black

[This message has been edited by Z28 Boy (edited April 15, 2001).]

 

Are you sure you have the IAC hooked up right? There is a constant ground and power lead. If those aren't wired up right the IAC could be stuck open. That would be my first guess. Then I'd look at the idle screw but I bet you already did that. I have a strong feeling that the IAC isn't wired up right.

------------------
, Jon (350 TBI! getting 23mpg highway)
91 Red RS w/grey int, sq stereo (Alpine v12, kicker solo, MB quart premium etc)AIM: JPrevost

• Holley 670 TB unit w/ 1/2" spacer/adapter
• Edelbrock RPM vortec intake
• 350ho 330hp vortec crate motor
• 8" harm. balancer
• Stewart stage 2 water pump w/160 thermo
• SLP tri-y headers to full 3"
• Rebuilt trans w/ SLP shift kit
• Centerline 16x8's all around
• 36/24 mm sway bars
• Full poly bushings, even motor mounts
• SLP LCA and panhard
• Alston SFCs
• Edelbrock 3 point STB
• Global west steering brace aka wonderbar
• Eibach pro kit springs
• Bilstien high perf. struts and shocks
• All this and I still have AC

My websiteAny questions?

 

hmm..i just took the a,b,c,d from teh old one and matched it up to the new one. i will check it out to see if i shouldnt have done it that way..thanks.

-brian

------------------
1991 Camaro RS - ultra blue metallic, t-tops
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
10 bolt - SLP zexel torsen differential, GM 3.42s
z28boy.fbody.com
z28boy@twcny.rr.com
AIM - "Z28 Boy"

1998 Pontiac Grand Prix GT - 2 door, black

 

Definately sounds like a vacuum leak.. keep looking, probably one of the ports on the throttle body, or, the gasket



[This message has been edited by Pablo (edited April 16, 2001).]

 

btw which injectors are in the throttle body

 

if its an ecu and chip for a 305, the iac wires need to be changed. Is this the case?

i know you have a 350, but i dont know what ecu you have.

i know you covered the tps, and its ok. the linkage you said was correct.

try to watch the iac, and see if it moves in and out correctly.

when i had my 454 on, my engine would make the hissing (shshshshshshshs) noise at startup for a couple minutes, but after driving around for a couple, it went away after warming up.

another option... put the holley back on and sell the 454 to fastbroker, he really really wants one.

[This message has been edited by snflupigus (edited April 16, 2001).]