ok, so finally went to check out my 91 RS 305 TBI Camaro..

Basically, i'm officially the 3rd owner of the car. the first owner kept up with it to the point of having logs that he meticulously filled out all the way up until the point of sale to the next person, who gave it to his daughter who kinda trashed it out..

the motor and transmission work and run strong, but there's a minor issue..

to give you a little bit of back story, my dad found the girl somewhere or another and she wanted to sell the car because "it wouldn't run anymore"..

she says she had someone change the intake gasket because it was leaking. (or so the mechanic told her)

now, if that means she ACTUALLY had it done or not, i don't know.

what it probably means is that it needed to be done and she didn't have the money.

anyway, my dad gave her the money for it and was going to yank the motor for another project and CRUSH THE CAR.. then decided not to, and had it sold to another guy for a significant profit, but for some reason kept it, then realized i needed a car (hadn't talked to him for a while due to life conflicts) and gave it to me this last week.

anyway, that's the back story.

He had it towed to his shop, tightened the battery terminals and the thing fired right up with no issues. the girl mentioned this (which i'll explain) when she sold it.... she said she was afraid of it dying on her in traffic with her kids in the car and all that.

Basically, what he found was that when it first starts, it will idle up, and run fine, then when it idles down, it will drop below idle and die if you don't keep your foot on the pedal and give it gas to keep it running... but once you get doing, it won't die...

and once it is thoroughly warm, it doesn't have the issue... we fired it up yesterday and it had the problem, then fired it up today and it didn't have the problem at all... the only thing that changed was that he put a can of Sea foam in it a few days ago that hadn't had a chance to work its way through the motor before letting it run for about 45 minutes between yesterday, a short test drive and firing it up today.

so.............


WHAT MAY BE CAUSING THIS?

i'll give my non-TBI expert opinion and say that:
1. either it NEEDS an intake gasket still
2. they didn't hook a vacuum line up / missed one (does this motor USE vacuum lines?)
3. They crossed an electrical plug somewhere (are there any plugs that could be confused with another that fit in the same plug style? i know for a while they weren't very good about giving everything it's own proprietary plug)
4. some kind of sensor SOMEWHERE... maybe the Throttle position sensor, or .....????????? what other sensors are on this motor? i know it doesn't have an MAF, but i have no idea what it DOES have...


what are your opinions???

i haven't hooked it to a scanner yet, no one i know has an OBD1 scanner.. one of his friend's does, but it will be a few days before we can take it by there, and i live about an hour away, so it's inconvenient for me to run back and forth...

I figure that someone here may have had the issue at some point and know what's causing it..

thx...

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it's actually difficult for me to thoroughly describe the issue because my main focus was to spend time with the family, not to work on the car, so my experience with the issue it has was limited to "look it starts"........ "see, that's what it's doing.. it idles up, then idles down and dies"....... "ok, close the hood, let's go for a ride real quick and burn some of the rubber off these old tires" (which we did... thoroughly... but i'm still not happy with the 170hp.... ) then we didn't mess with it except for starting it earlier this morning to move it over to the shop so we could start putting a window in it...

so, if you say "does the car have this? or .. "see if this wire is doing this?" i won't be able to tell you.. i'm nowhere near it and didn't look thoroughly under the hood to see what was what... but... i get the rims on wednesday, so i'll be up there getting the tires on them, and putting the wheels on the car / cleaning it out / finishing the window, and getting it ready to get inspected and bring home. goal is to have it here in the next week. Not going to spend another winter riding my motorcycle everywhere. i refuse to.

 

bump

forgot to mention... the RPM's read around 4000 HIGHER than they actually are at any given point on the gauge too.. not sure if it's related or helps the diagnosis...

still need the info though...

 

the basics are the basics and must be confirmed before one can continue

does all of this occur even after you have

replaced all of the spark plugs
replaced the cap and rotor
replaced the plug wires
replaced the fuel filter
replaced the air filter
replaced the pcv valve
replaced the breather
replaced the O2 sensor
set the timing

what were the symptoms before and after you replaced all of the above?