Air-Fuel mixture too rich problem
#1
Air-Fuel mixture too rich problem
Hi, I would like to ask if somebody could help.
The engine is shutting off due to the air-fuel mixture has been to rich. The car is Mazda 626.
Hoping for your kind response. Thanks.
The engine is shutting off due to the air-fuel mixture has been to rich. The car is Mazda 626.
Hoping for your kind response. Thanks.
#3
He has a "MAZDA 626, 1993, AUTO" based on his last post... 05-13-2007, 03:39 AM.
But yes, how was it determined that it is running too rich?
Might a wild and uninformed guess be the O2 sensor, hixx? WhaddoUthink? It being a '93 I'm guessing its never had a new one and the car probably has 200k+ miles on the clock.
#4
It could be but it depends on what he means when he says it runs so rich it causes it to quit running. It might cause it to die at idle but i would lean toward the MAF or torn intake boot. It being that old it could be tons of things. It might have jumped time or have a bad coil/distributor,plug wires etc. Possibly a restricted exhaust. Pretty much limitless on the possibilities without more info.
#5
Did the '93's have MAF sensors then?
I thought of the torn intake boot, but also thought that would tend to make it run lean?
Bad coil/bad wire. Good guesses.
And you're right!! That old and anything might be up with it.
#6
Did the '93's have MAF sensors then?
I thought of the torn intake boot, but also thought that would tend to make it run lean?
Bad coil/bad wire. Good guesses.
And you're right!! That old and anything might be up with it.
#8
Hi guys, yes it's still the same Mazda 626 Auto '93.
Regarding the too-rich observation, this is the what happened.
First symptom is hard starting. So I replaced following:
-throttle body (surplus)
-distributor assembly (surplus)
-spark plugs (brand new)
However, same results were observed.
I replaced then the fuel pump (brand new). After replacing the fuel pump, the car now starts easily and smoothly but after a few minutes (approx. 2-3 min.) you will notice that idle becomes rough until it shuts off. You can then smell the gasoline coming out of the muffler.
I tried to remove the spark plugs and noticed that it is wet with gas.
That is why I mentioned that it is too rich.
By the way, I consulted a mechanic, he said that the problem is the computer box. What do you think?
Hope this provides key information.
Thanks.
Regarding the too-rich observation, this is the what happened.
First symptom is hard starting. So I replaced following:
-throttle body (surplus)
-distributor assembly (surplus)
-spark plugs (brand new)
However, same results were observed.
I replaced then the fuel pump (brand new). After replacing the fuel pump, the car now starts easily and smoothly but after a few minutes (approx. 2-3 min.) you will notice that idle becomes rough until it shuts off. You can then smell the gasoline coming out of the muffler.
I tried to remove the spark plugs and noticed that it is wet with gas.
That is why I mentioned that it is too rich.
By the way, I consulted a mechanic, he said that the problem is the computer box. What do you think?
Hope this provides key information.
Thanks.