4A-F engine - Toyota Nation Forum : Toyota Car and Truck Forums

DV1VNU · 04-11-2010, 03:20 AM

Hi! The exhaust smoke coming from my 4A-F engine, when in acceleration is color white...and smells like unburned fuel...but the car runs fast. When in idle, the RPM fluctuates and there is a strong smell of unburned fuel in the exhaust. I just purchased the car recently.

Help! :-)

Rolla88 · 04-11-2010, 10:13 AM

When you get a change check your plugs, make sure they are not black, if they are it means that you are running very rich. Also when this happened to me it was because my valves were very dirty and they were not sealing right so fuel escaped unburned and it would cause the car to smoke. Start cheap, put some car cleaner in the carb and some fuel Lucas fuel treatment and if push comes to shove treated it with Seafoam. You might be able to clean it up without taking it to a mechanic. The car might have been mistreated b4 you got it.

Evo_lucian · 04-11-2010, 10:19 AM

White smoke is usually water or coolant issues.black or dark grey is usually fuel and blue is oil.

Lift oil cap and check for moisture or milky substance.

Rolla88 · 04-11-2010, 10:29 AM

If the valve seal are bad it would smoke white, it could be bad piston rings.

***REN69*** · 04-11-2010, 10:46 AM

4AF... sounds like the carb needs a good tune.

Evo_lucian · 04-11-2010, 11:05 AM

No it would be light blue. I have blown all too many gaskets,rings etc over the years. The op needs to describe the problem a lil better. Does the smoke appear at high or low vaccuum? Does it smoke at when you first start up and idle?

A leak down and compression test will help you figure if its bad rings or seals easy, but like I said idoubt its any of these if the smoke is white

Evo_lucian · 04-11-2010, 11:07 AM

Or what ren said

90 GP · 04-11-2010, 01:08 PM

Sounds like it is flooding due to a high float level. The carb has a float bowl level sight glass on the side of carb. The level should be in the middle of sight glass.

***SCT*** · 04-12-2010, 12:25 AM

I agree with the carb. I've been through several.

DV1VNU · 04-12-2010, 09:55 PM

The carb has been overhauled with the help of a carb repair kit. Still has white smoke when accelerating. No white smoke when in idle. But the presence of unburned air-fuel mixture is still there. I'll check the compression of the engine. The level of water/coolant in the radiator didn't go down since I got it(car).