David Fite

Just got my 92 over the weekend. PO said it was originally a 305 TBI, but was converted to carb and has 350 heads/intake.

1.I took the air cleaner off and see "TBI" and "305"... so do I have TBI or carb? or what? I talked to the guy that did the work and he's definitely not super-smart but the car runs so it's at least doing something.

I've done lots of little projects on other cars (brakes, etc..) but plan on redoing just about everything on this one and learning along the way.

2.my gas pedal sticks really hard, I was hoping to find 2 springs on the carb (so I could take one off and loosen the tension), but I see what I think is a TBI and there are no springs, so trying to figure out what's sticking. It's like you have to "break" it free when you first press it.

3.I hear a "whistle" while the engine is running. any idea what that is?

4.sounds like the a/c kicks on and off every few seconds if I turn it on. the fan comes on and runs solid, but I hear the compressor (maybe?) come on and off, and the engine changes as you hear it kick on and off

Thanks for the help in advance.

aliceempire

iTrader: (14)

1.It's TBI. The things that the red, blure, green, yellow wires are attached to are your injectors.
2. You could have a bent throttle shaft in the tb, gummed up butterfly valves (causing them to 'stick' when closed) or a bad throttle cable.
3.Vacuum leak? hard to say without hearing it.
4. A/C is supposed to cycle on and off. They all do. No sure why the fan stays on all the time though..been a long time since I've ran A/C on any of my vehicles so it's hard for me to remember when the fans turn on.

stegal

I had a sticky throttle pedal and just sprayed wd 40 on it and it went away.

David Fite

Thanks. I thought it was when I saw the TBI but wanted to make sure I didn't miss something dumb. So just by looking at the pics do you think the only thing I'm missing is the original air cleaner to put back to stock? I don't know if this is related but when I push the throttle, I can kind of hear something down in the front drivers corner doing something. Like maybe a cable goes down there and does something with the factory air system or something? Hopefully that makes sense.

Also, it's cold out but I have to start it 3-4 times and really rev it up to keep it going at first. It has new plug wires, but looks like the plugs are old and rusty. Should it start better than that? I thought any kind of fuel injection should keep it running better in cold weather.

Sorry, another question... does anyone have a checklist of things to look for to make sure I have everything TBI related still in place and working? I can take more pics if that helps.

David Fite

Where exactly did you spray?

stegal

I sprayed the throttle pedal pivot point under the dash. It took a while to work but it did get better. Mine was just like yours in that it was sticky at the start of depressing the pedal.

jharrison5

I had the same sticky throttle cable issue on my '93 suburban and I used liquid graphite for bicycle cables to fix the issue. The graphite won't attract dirt like an oil would.

However a new cable is around $20 online and isn't too hard to change.

antares57

iTrader: (8)

It looks as if your vacuum hose from the EGR solenoid to the EGR valve is missing. If the coolant fan switch wire is disconnected or the coolant fan switch is defective the fan will run all the time. Also, both of my TBI's were wired by the previous owner to run all the time.

David Fite

I'll look and see if I can find a picture of the EGR hose. Not sure what that is or where it goes. If anyone has a pic of it please post.

David Fite

Nailed it I think. The butterfly valves have some gunk in there and feels like that's what's "breaking free" when I mash on the pedal. Now the question is can I clean that quick and easy with some cleaner? Or do I need to remove the throttle body completely and buy a TBI tune up kit or what?

Damon

Spray some carb cleaner on it, let it soak a couple seconds and start the engine. Spray more while it's running- little bursts, not so you drown the engine out.

If that still doesn't get it done, open the idle speed screw JUST A SMIDGE. It's also possible the throttle plates are just closing so far they're wedging in their bores when you come back down to idle. The throttle arm is supposed to come down and stop on the idle speed screw, but if that's not catching it, the next thing that will prevent it from closing further is the throttle plates themselves wedging in their bores. And under vacuum (engien running) that can cause the nasty "tight spot" you feel when you first try to open the throttle.

aliceempire

iTrader: (14)

Agreed, Spoken like a true carb tuner.

antares57

iTrader: (8)

Hard vacuum line outlined in red seems to be missing.

David Fite

I think this was the problem. Took the whole thing off today and tried cleaning and scrubbing everything I could, but to no avail. Finally found the screw you were talking about and it wasn't even coming out at ALL, so it was closing the butterflies way too far. I turned the screw just enough until it stopped "catching". Seems to be much better now. Now I just need to get all my other problems fixed so I can drive it...

David Fite

I think I finally figured this out too. If you look at the pic I think I found the line that you're talking about. It's just dangling there not doing anything. I think I need to maybe re-route some stuff to get it physically able to hook back up.

What will this do or fix when I get it hooked back up?

antares57

iTrader: (8)

From autozone:

When not replaced (or connected), vehicles can experience poor engine performance, poor idle, high NOx emissions, failed emissions test, hesitation, engine surging, or CEL/MIL illumination (Code 32)

David Fite

Thanks antares57! I need new plugs, among other things, but that could explain why it's not the best starting/idling vehicle. Plus I have a check engine light. (could be the code32 but haven't checked it yet).

David Fite

Got some emissions line from advanced auto and cut a piece to fit. I noticed the "L" piece that goes into the module was backwards compared to your picture. I swapped it around and then realized the one line that's going from the TB to the module was actually capped off and inserted in with a rubber cap on it. So not sure if it's correct or not but in the end I basically made it match what you have in your picture. I don't know if the PO was trying to EGR delete or what.