Hello i`m new. love the site. ok here goes very wierd pronlem, i just put long tube headman headers on my 89 firebird and today i just put my new taylor 8mm spark plug wires on it. heres the odd part when i went to start it. it fires up idles great i try to rev it a bit to hear them open headers and the rpms goto 2,000 on the tach but it wont go back down! so i figures it was a vacum hose on my air cleaner. i reatached the air cleaner and all the hoses and it still does it. anybody know?

 

One question right off the bat. IIRC, and I could be wrong, the full length hedmans do not have a oxygen sensor bung on them. Did you have one installed, so that you could run your O2 sensor?

 

no i gotta get one but i`m waitin on a tuned port to come that i ordered off ebay

 

I don't know for sure what the effects will be of running without an O2 sensor, but both TBI and TPI need one on there to run properly.

 

do you mean the tach doesnt drop? or the engine just stays at 2 k

 

see how it works when you get the o2 hooked up properly. The ecm wont like not having that sensor. Probably also a good idea to consider getting a heated O2 for your LTs. Not absolutly necessary but it would help fuel economy and emmisions.

 

The 02 wouldnt have anything to do with the car not revving over 2,000. All it will do is cause him to stay in open loop and waste fuel, but he should still be able to rev past 2,000.

 

just a thought, maybe the linkage is messed up , or hitting the air cleaner? i thought he ment it reved to 2 k and never dropped back from 2 k

 

yeap, I read it wrong Sounds like a vaccum leak to me or could be the linkage like you said.

 

i have no clue what vaccum leak would make a car not rev back down. im thinking its a kink in the throttle linkage or somewhere within the springon the tbi linkage, theres a problem, that or your idle screw got turned, ALOT, or yout timing is seriously jacked up.

 

i have the o2 sensor plug in it just hang off the sway bar.

 

The eninge stays at what ever rpms i put it to.

 

Definitely a kinked throttle cable! DO NOT DRIVE IT LIKE THAT!

 

lol no way i`m puttin it in drive lol,i`m kinda thinkin somehow the cruise control is stuck on or something stupid like that. its drivin me nuts though, i`m gonna tear the cruise control off tomarrow morning.

 

The cruise control works off of mph, not rpm. Check and make sure you dont have the throttle cable caught on anything or bent at all.

 

will do. hopin to get the bird doin 13`s by next summer gonna load up a tpi full of slp goodies.

 

Sounds like the return spring is not doing the job! Does your TBI have a return spring like a carb? I it does it sounds like it came unhooked.

 

nah the throttle return spring is made into the linkage, ..but that very well may have broken.

like i said before, its prolly the throttle cable kinked. or your linkage spring broke. spray it down with some carb cleaner.

stupid question but, did you forget to put the lil metal retainer clips on the throttle cable AND the cruise control cable?

i did that once, and hit the road, car stuck at wide open throttle, in the rain, with a car going super slow infront of me. that sucked. i managed to not hit them or tear up my car though....thank *** for neutral and a key lol....

maybe your TPS is binding, and not letting your throttle drop.

and yes, your cruise control will only engage at 40 mph. i know, i use mine enough. check the entire linkage assembly though. i suspect the problem lies there.

 

You still need to fix that ASAP.

 

i second that, unless you plan on throwing the tbi and ecm away, if thats the case, drag that dirty bastard down the road like that til sparks fly, ...o2 sensors **** me off, ....make it take one for the team! heh

 

Dear lord tell me you're kidding. This will tell the car that you're super lean and will dump your whole gas tank into the little 305...

 

i`ve checked all that u guys mentioned today, i pushed the throttle with the engine off and it returns.i have no ideas left lol about to say screw the tbi and throw the tpi on when it comes in.

 

man if you think you have problems now, wait til you do the tpi swap. sure itll work, but i heard it was a bitch to do. i wouldnt know for sure though seeing how ive never done it. maybe your pedal is getting caught on the carpet?? lol i dunno.....check the idle air control as well.

 

check teh throttle with the engine running. The forces from the vacuum on the butterflies will sometimes cause binding that doesnt happen with the engine off.

 

lol theres no carpet. i`m doin a resto kinda tempted to leave out the interior. but actually in my tbi`s butterflies even with the motor off there has always been a weird bindint sound coming from it like a chirp.

 

sounds like the tbi casting is badly worn around the throttleshaft if it makes squeaking noises. Tahts probably the butterflies hanging on the walls of the barrels. To be sure, firmly grasp the throttle shaft and move it around with the throttle open partway. If there is play, then its time to replace the tbi or have it rebushed.

 

u maybe right it has 160k orginal miles with a semi fresh rebuild on it. the guy i got it from had it rebuilt probably thing were wearin out on him.he replaced alot of things.

 

I went from a carb to TPI in my 1988 Monte Carlo SS and it wasn't too hard of a swap, I used an external fuel pump and ran a 5/16" steel (I used brake line) line for a return. The wiring harness comes out pretty easy and the new computer hook-up was a snap.
I had to have a custom chip burned tho 'cuz I am using Speed Density, a T-56 6-speed, 406 c.i.d., the TPI builds incredible torque!

Tony is right about that 02 sensor, you MUST have that hooked up and functioning properly!!!! The computer will indeed see the A/F ratio as SUPER LEAN and 'try' to get it right by telling the injectors to richen it up!

 

lol, my friend has almost the same exact setup in his monte except he has a vette L98 350 and not a 406.