camaro1185

Heres the back story:
Over the weekend i went to look at a 1988 all orig. 350 iroc with 75K miles. From what i could see, the rear end seems to have a very slight leak around the cover, it def. needs pain and the seats have seen better days. but there is no rust/rot at all, everything is orig. and everything on the car works.

My question is that when the car is started there is smoke that comes out of the exhaust, but im about 99% sure its not buring oil. i stuck my finger in the pipe and there is black soot build up, and no oil residue, so i think its running rich. Although after it was running for about 6 mins or so and after i had reved it, it didnt go away. The car was only run about 3K miles in the last 8 years so im sure there is a ton of carbon build up that needs to be cleaned out.
Do you think that the engine is in bad shape and that im gonna be getting myself into a big headache, or is getting the car to run a little more lean easy?
thanks for the help.

Jaydog143

iTrader: (1)

so what color was the smoke??? And a car like that that sits for so long is gona have bugs period. The car needs to be ran for a long time with fresh gas and all fluids changed.

camaro1185

Jaydog, thanks for the reply. if i remember correctly the color of the smoke is whiteish/grey. Am i right in assuming its not buring oil since the only residue i see when i stick my finger in the exhaust pipe is carbon and NO oil? I understand there are going to be bugs. Other than doing a full tune up, seafoaming it to get rid of the carbon, and changing all the fluids what else should i do to make sure its a safe vehicle?

Jaydog143

iTrader: (1)

Just because there is no oil on your fingers does not mean its not burning it.

First thing I would do is pull every single spark plug and look for wetness/oil on them. Get a multimeter and ohm test each fuel injector. When a car sits for that long no matter how many precautions you take somethings going to mess up. I have especially noticed with fuel injection the injectors like to stick and/or hang wide open when theve sat for so long. But like I said before, sometimes all it takes is driving the **** out of it to get it to come back to life and kinda "clear out" so to say.

Like with my car for instance, when I first got it it was a dog and I couldnt figure out why. It was an injector that tested fine but was not firing. So I took it out and literaly drove it like I stole it and all of a sudden that injector kicked in and my idle came back and the car ran great.

camaro1185

so whats the best way of draining the old gas? should i siphon it off? is there a way to check if the o2 sensor is the reason for the rich mixture?

Jaydog143

iTrader: (1)

Doubt its the o2 as these usually go bad with use, well this car hasnt been drivin much so......but I could be wrong.

If it doesnt have a whole lot of gas in it at the time just fill it up with some premium and run a few tanks through it. I would replace the fuel filter while your at it just because. If it has a full tank you could siphon a lot of it out and then fill it up again.

does the car throw a code "check engine light" ?

camaro1185

Good to know. i will drain the gas and run a few tanks through. if i run through like 2-3 full tanks of new gas and it still runs rich, will i be doing any damage.

As far as the CEL light, no it is not on. This is what got me baffled. its smoking out the exhaust, not a ton, but when its reved you can see it when sitting in the drivers seat. I couldnt figure out why the car would be running rich and no CEL light. Maybe then it just does need to be run and there is nothing wrong like the 02 sensor etc.

400z85

When an injector sticks closed if it's on the bank with the O2 sensor the computer will try and compensate by richening the fuel mixture because it thinks that all the injectors are firing.

camaro1185

i had mistaken the smoke as running rich. it was actually the valve seals leaking. for the time being, i put the oil additive in and it has completely stopped the smoking, but it still does run slightly rich (no smoke, but you can smell gas), is that something i should worry about, or do all camaro do that?

smart7final

Check the the valve guide seals. On mine which is the 305 before I bought it it had sat for 7 years, and mine were bad.for being only 83 bucks it worked and they arent hard to do with the right tools.

TORN

iTrader: (17)

Sounds like you bought the brother to my car lol 83k here. Mine ran rich too when I bought it and after fresh gas, filters, o2 sensor, plug wires, plugs, rotor + cap it ran better but still rich. Then I replaced my thermostat that was stuck open so the car would warm up and it leaned right out. damn computer was trying to warm the motor up lol. Good luck

TORN

iTrader: (17)

oh l also replaced my valve guild seals too now its starts up much much easier and my number 8 spark plug no longer fouls out from the oil.

omnipotentgoku

iTrader: (1)

I don't even know the right question to ask, I believe i may be having a similar problem, possibly a stuck injector, or a problem with the valve seals.

https://www.thirdgen.org/forums/tech...ml#post4278690

If it is the valve seals, how does one replace such a thing. I am a virgin to cracking open my engine. I think i've gone as far as the upper manifold, so I would not be to experienced in working on internals.... any updates on this situation or suggestions?

SoTexZ28

I just got a 88 IROC Z convertible, 305 TBI, it too is running rich. Of all the suggestions here, what would be the first thing one should check/replace?