Vetal

iTrader: (3)

Finally I've received the car I was wanting for a long time 98' Firebird, manual, bought from one of users of the forum.

However it has few engine problems. First, it doesn't idle without pressing gas pedal until engine is fully warmed up. Annoying, but not lethal.

Second, engine works bad under acceleration when not fully warmed up.
And what I don't like most, when standing still and revving, car shakes badly, although engine doesn't miss or smth. Especially at 2500rpm car is shaking really bad, vibration is terrible.
Car was said to have cams, it has headers and magnaflow.
Please tell me your opinions, where to start... This is my first american car and I'm a bit disappointed

Caribe

iTrader: (1)

I would start by checking all your plugs and wires. Make sure those wires are on properly especially the rear ones.

Vetal

iTrader: (3)

How to check them (yes I will do the search too ?

Also I forgot to add that the car was sitting for 2 months before I got it.

Sunset'01Z

iTrader: (10)

well dont be dissapointed because it's an american car. i've put 44k miles on mine and i have only had a handful of small problems, luckily i was able to fix them myself.

to the problem, is the car throwing any codes? if so, post up what they are. and if the light isnt on, check and see if it comes on when you first turn the key. all of the lights come on for a brief period when the key is turned.

Vetal

iTrader: (3)

Do you mean "Service engine soon"? It comes on when I turn on ignition, then comes off. I don't see any error codes on the panel

Vetal

iTrader: (3)

Small update - when first started, engine puts out clouds of smoke, probably oil smoke...

OldSchoolFormula

First it only has a single camshaft. Second, has it been tuned for the cam? The smoke your seeing is probably unburnt fuel. What color is it?

Vetal

iTrader: (3)

Grey color. I think it's oil, because:
a) looks like oil smoke
b) it goes away when the car is warmed up

Starion

iTrader: (5)

Does it do it on a cold start? hot start? or both?

OldSchoolFormula

Oil burns blue. Fuel burns blackish. It would also go away when the car enters closed loop and the car of course can idle on its own. You need a TUNE, man.

Sunset'01Z

iTrader: (10)

does the smoke puff when you first start the car or does it smoke evenly untill its warm?

Vetal

iTrader: (3)

It smokes on cold start (grey smoke with burnt oil smell), for ~2 minutes, gradually going away

Sunset'01Z

iTrader: (10)

that sounds like a tune issue. it's not burnt oil, the car doesnt know what to do with the cam so it runs too rich.

Vetal

iTrader: (3)

I still think that it is burnt oil smell that you can feel... It's not unburnt petrol. In a couple of weeks I'll put my wideband and see what is happening when cold starting.
Yes maybe it's a bad tune. Generally, what is changed in tune when installing cam to allow car to idle normally? ignition advance change? mixture change?

Black FormulaLs1

iTrader: (10)

call ron at vengeance Racing....best help i can give

keliente

iTrader: (22)

First give us a list of all the modifications...be specific about cam size, whether supporting mods were done with it (springs, chain etc) and all of the details.

Secondly has it been tuned?

Vetal

iTrader: (3)

Previous owner said it was tuned.
Here is one more piece of info from him:
"I have new valve seals coming...i get a little smoke on deceleration, but it was dead even at 140 across all 8 cylinders when i had a compression test done last month..."

I'll post cam spec a bit later

Sunset'01Z

iTrader: (10)

compression tests dont test valve seals. it's ok, valve seals arent that hard to do. goodluck.

Quickin

I think your valve seals are bad, allowing oil to drain onto your plugs after the engine is shut off. That oil takes time to burn off until the engine is warmed up. It will run shitty until the plugs get hot and the oil/crud burns off the plugs.

It also explains the puff of smoke on start-up.

Do a spark plug change and see if it starts and idles nice the first time.

When you cruise at say 45mph down the road, than you stomp the gas pedal to the floor, do you get a huge cloud of smoke, and than as you keep accelerating it clears up? Thats bad valve seals in the heads. I had this, I had the heads rebuilt and it was 100% cured.


.

Vetal

iTrader: (3)

Previous owner said it was always (since mods/tune) hard to warmup...
I'll do "at say 45mph down the road, than you stomp the gas pedal to the floor" thing