Hey my first time posting on this board. I just bought a 89 RS with the TBI 305 and 5 speed tranny. I cant pass emmisions at Idle. It passes just fine at 2500 RPM but at Idle the co's are 4% instead of the limit of 1.2% and the HC's are at 720 instead of the 110? what give what would make it do this Ive gone thru the routine of checking the PCV and EGR they are ok. and for a car that only has 37K on it I wouldnt think Id run into this problem. the car did sit for a month and a half but it passed with flying colors just prior to that. If ya have any ideas shoot em my way. Thanks

P.S. Would it be possible for me to send it out to one of you guys and have you rebuild it and put new rods and jets and all the good stuff in it so I get the max out of it but still pass emmisions ?

forgetting a ton of stuff, I live in utah, so if your in like colorado Idaho or somewhere close itd be great because I can send it over night along with the money and enough to send it over night back here. ok time to shut up see yall later

[This message has been edited by OldBlue (edited June 10, 2001).]

[This message has been edited by OldBlue (edited June 10, 2001).]

 

Well, TBI stands for "throttle body injection", which is not a carburetor. That means it operates via two injectors in a throttle body, controlled by the computer that decides how much fuel to inject based on throttle position, vacuum, atmospheric pressure, and oxygen content in the exhaust. It also means you do not have rods or jets, or float or needle & seat or most anything associates with carbs except throttle blades.

If you are failing idle but passing cruise, that sounds a lot like a leaking injector. I'd suggest a hefty dose of a fuel cleaner that is put into the gas tank. A fuel filter change either before or after the treatment is a good idea (if the fuel tank is especially dirty, you may have to change it more than once). It also cannot hurt to change plugs, wires, cap & rotor, and air filter. The O2 sensor may also be shakey, but I don't tend to think so since you passed cruise. However, they aren't that expensive or hard to replace, so it wouldn't be a bad idea to change it as well before you go to get sniffed again.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, LT MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/95.5 @ 5800' Bandimere.

 

Thanks, sure looks like a q-jet on there but it has 2 injectors sitting on top. Im new to this 3rd gen stuff but, im well versed in 2nd gen applications as I have 2 right now. sorry for my ignorance on the TBI/TPI systems.

 

Here's my two cents. You mentioned that the car was sitting for about a month and a half and passed with flying colors and now it is failing. My brother had a similar problem on his Mustang a while ago, sorry about using the 'M' word. He parked it for the winter and when he had to pass emissions he started it up and failed. He took it to the mechanic and both his O2 sensors were bad. The mechanic says that this often happens if you don't start your car up every once in a while. So that could be a possibility. Just an idea.

 

I found that overdriving my smog pump, using a small pulley and blocking off the dump valve, seems to work. Georgia doesn't have smog checks (except Atlanta) but I had my emissions checked at the local good ol' boy garage just to see if the theory worked.

I got that idea from a 1979 issue of Car Craft. Their project was to get their trick '78 Z28 to pass California emissions. The EGR was bogus, the cat hollowed out, but that overdriven smog pump was flushing so much air into the exhaust that it passed!

I wouldn't LEAVE the pump in that condition but it ought to get you past without too much expense.

 

Ill check it out thanks

 

moving to the TBI board...