Carbon fouled plugs, oil from breather, and high fuel consumption

[Balidio]

I just bought a 98 KIA Pride GTX with an automatic transmission. The engine is the original carbureted 8-valve SOHC B3 with approximately 180k kilometers (about 113k miles). Only parts loading the engine beside the tranny are the alternator of course, and the A/C compressor (IOW no power steering).

The previous owner knew nothing about automotive maintenance. All he did was put gas in it and drive. So basically, the poor thing has been completely neglected for years.

Here's what I've done so far: (as of September 25, 2009)
* Flushed engine with 3 litres of SAE 40 oil and .5 litres of flushing oil
* Replaced oil filter and filled with Castrol Magnatec 10w-40
* Flushed cooling system with Prestone Super Radiator Flush
* Filled cooling system with Prestone Antifreeze/Coolant
* Replaced fuel filter
* Filled tank with 93 RON (AKI 87 back home) unleaded gasoline and a bottle of STP Fuel Injector and Carburetor Treatment
* Adjusted distributer timing
* Adjusted both Throttle Idle Speed and Fast Idle Speed
* Replaced timing belt and tensioner bearing
* Replaced both alternator belt and A/C compressor belt
* Replaced accelerator shaft, CV joints, tie rods, and rack & pinion
* Replaced engine and transmission mounts

The symptoms that it's exhibiting are just as in the title. After topping off the oil and running about 600km, I had to add another 200ml. Also, it's only getting about 7-8 km/l (about 18 mpg). Now keep in mind that most driving here stays between 40-80 kph (25-50 mph) when there's no traffic. This holds true for about 80% of my driving here; the other 20% is bumper to bumper moving about a car's length every 30 seconds. Brand new, the car is supposed to be getting about 12-13 km/l (about 30 mpg) in these driving conditions. So I was expecting about 10-11 km/l (about 25 mpg).

Found that the automatic choke was stuck, so opened it permanently (cold starts are definitely not an issue here in the Philippines), but it still runs way too rich. Adjusted the air:fuel mixture as lean as possible, and advanced the timing as much as possible while keeping the idle smooth around 950rpm, but still running way too rich.

I thought my compression might be low due to worn rings, which would also explain the oil from the breather. However, if I was getting blowby due to worn rings, wouldn't my plugs be oil-fouled (wet-fouled) instead of carbon-fouled (dry-fouled)? I'll have a compression test done tomorrow to see if it might be the rings, and I'll try hitting the carb with some cleaner to see if it clears anything up.

BTW, I already checked my PCV valve, and it's still good. I also consulted a Bosch certified mechanic here to see if changing the rings would be my solution for the blowby. He told me the blowby is a common illness of Prides/Festivas. He said that changing the rings would eliminate the blowby for about a year, then I would experience oil from the breather again. How much truth is there to this?

Any relevant information and advice would be greatly appreciated.

:newb:

[WmWatt]

Would a clogged exhaust gas recirculation valve make the engine run rich? They are easy to remove and clean. I posted a description at
www.ag384bn.bravehost.com/Cars.htm.

[GenevaDirt]

blowby is not a common problem at all....these engines last forever, I am sure the issues stem from neglect and once fixed will be good for a LONG time if taken care of.

[Balidio]

Thanks, WmWatt. My understanding (correct me if I'm wrong) is that the EGR valve takes excess/unburnt gasses from your engine and recycles them into the intake to "re-burn them. I guess it could cause rich mix if you're recycling unburnt gasses back into an engine that is already not burning completely. But I doubt that would cause the incomplete burn or the excess fuel consumption. Anybody got any inputs on this?

[Balidio]

Thanks, GenevaDirt. I read that both the Festiva and the Pride were manufactured in Korea by KIA, but the 121 and 323 were manufactured in Japan by Mazda. All those cars used the same B3 engine in one model year or other. The mechanic I spoke with said that the oil from the breather is a common problem for the Prides, but the Mazdas don't have the same problem. The reason he gave was quality of parts (Japanese vs. Korean). Now I know that the US has much stricter quality control for imported vehicles than the Philippines, so I can see some possibe validity in what the mechanic said. Maybe KIA made the Festivas to a higher standard for export to the US than they did the Prides for export to the Philippines. Even American brand products manufactured here are made with a lower standard for domestic consumption than those made for the US market. Do you think there is some way validly to confirm or deny the mechanic's statements?

[GenevaDirt]

it is possible I guess....but no one from there or other places has complained about that problem that I know of. FestivaGTX is from the Philippines...maybe he can answer....there are a few others from there too.....hopefully they will chime in.

[WmWatt]

I think you can safely ignore my suggestion about the EGR valve. I looked up it's operation on Google. It lowers combustion temperature when the engine is running lean to reduce nitrogen gas.

[Balidio]

Hey, guys, thanks again for the feedback. We shot the carb with cleaner and did another tune-up (adjusted distributer timing, throttle idle, fast idle, & air:fuel mix) yesterday. I can't believe it myself, but we got the best results from retarding the distributer timing all the way and calibrating everything else to that. The engine idles smoother and stonger now than anywhere else in the distributer's adjustment range.

It's still burning a little oil (blueish-white exhaust when revving), but it's burning cleaner (significantly less carbon build-up on the plugs). I'm also still getting oil from the breather. I'm going to run it like this for a couple days and see if there's any change in my fuel consumption (my first concern).

As for the oil from the breather, we just put a hose on it that just hangs over the intake side of the engine and ends at about the bottom of the oil pan. At least this way it won't make a mess in my engine compartment.

The rings are probably worn to the point where there's enough blow-by to burn oil and build up more pressure in the crankcase than the PCV system can handle, hence the excessive oily smoke from the breather. This probably also means that I've lost enough compression to cause the incomplete burn, hence the carbon fouled plugs and higher fuel consumption.

I know the rings should be changed, and could very well relieve most of the symptoms. I'm more concerned that even after the rebuild, excessive oily smoke from the breather will recur in about a year like the mechanic told me, and I'm also concerned that it won't completely resolve the loss of fuel efficiency.

I could still use more relevant input and feedback from anybody with any better ideas. It's still going to take me a couple months to get the time and money to have the engine rebuilt, because my wife's expectancy date is in late November. So I can't afford to spend much or have the car not running right now; however, I can't keep spending money on wasting gas or have the car quit on us either.