dear babyhuey and support tech, i have read some of your replies to problems and it really sounds like you know alot and i was hoping you could help me out.
i have a 1988 Fuel injected 323 1.6 that i have driven to costa rica, my friend was driving it and it started to stall and run poorly and she took it to a mechanic and he supposdly cleaned the injectors along with replacing some vacuem hoses, it runs ok but now it is eating twice as much fuel,
the mechanic it was brought to said that it needs a new computer?
another says that whoever cleaned the injectors did a poor job and that the system could be bad.
tommorow i hope to locate a new oxygen sensor and start there.
what does it sound like to you???

 

I would first check to make sure that the engine is running at proper temperature. After running for a few minutes, does the temp gauge read about in the center or just a tick below? I ask this because if it is running cold it will give the engine extra fuel. Another place to check is the fuel pressure regulator. This is located on the nd of the fuel rail and has a vacuum hose connected to it. Pull the hose off and see if any fuel comes out of the regulator. Besides that how does it run? Is there black smoke coming from the exhaust?

 

hi bkey thanks for getting back to me.

it actually is running just a little cold just below were it usually does. the guage reads at about a quarter.
It wasnt me who brought the car into the mechanic and when i brought it back to ask him about the fuel consumption i remember him saying he flushed the radiator and maybe something else about the cooling system i dont remember. i beleive he said he changed the co2 sensor when i went to change it today it appears new.

also yes it is giving off black smoke.

and it runs good, has all its power it just eats gas. im barely getting 2.5 to 3 miles to the liter. its less than half of what it is normally.

you say to take a look at the fuel pressure regulator located at the end of the fuel rail?which is?
which i will look for. should some fuel come out of the regulator?

i dont want to get two far ahead of myself but i want to let you know a few other things.
it also appears that where there would be vaceum hoses coming out of the sides of the top of the injector housing there is only caps.
the vacuems that are capped is, on the left side one which is 1/4 inch,
and three on the right side 2x1/4 and 1x1/8inch.

i have an old chilton guide but there is very little in it on the 323, ive looked around a little online for a vacuem hose diagram, would you possibly have one that you could e-mail me or a place you could lead me online where i could view the diagram.

thanks so much for your help. jon

 

I would first install a new thermostat so the car runs at proper temp. If the thermostat is not operating properly or if it was removed with the coolant flush the engine computer will see that the engine is always cold and richen the fuel mixture.

The fuel pressure regulator has a diaphram and it controls fuel pressure and is controlled by engine vacuum. Sometimes the diaphram can rupture and allow un-metered fuel into the engine. There should be no fuel if the vacuum hose is removed. It is connected to the intake manifold with a short vacuum hose.

I added a vacuum diagram for your car too.

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thanks bkey,

i took the car in thismorning and the mechanic went through the checked the injection system and air flow meter, i have left it there and he is going to continue to check, he said that right now he is looking into the grounds for the fuel valves? that maybe one isnt grounded right and its keeping it from sending the correct message to the computer.

how does that sound to you?

im going to walk back over there and talk to him and i will ask him to change the thermostat also, would the message that it is running cold cause it to use that much fuel?

i will keep you posted, thanks

 

I think you're on the right track...Black smoke is excessive fuel being burned (Blue - oil, White - coolant) Your Chiltons should tell you what the proper pressure is in the fuel rail (at the engine), there should be a fitting that you can hook a fuel pressure gauge to get a reading.

If something wasn't grounded right, that function wouldn't work (so if the function is to regulate fuel pressure, it would not regulate.... and would either dump any fuel available into the motor, or stop sending fuel altogether.)

My $$$ is on the Fuel Pressure Reg.

 

thanks for all the info so far, and now i must wait...
ill keep you guys posted!

 

well my car has been at the mechanic for over a week while i have been away, and it is still not fixed and so it continues to eat fuel.

the mechanic has said he has checked everything related to the injectors and is going to
check the timing belt to see if it is a notch ahead or behind.???

after all that he has looked at could it really be this?
is it possible that it could be the ECU? this is what the first mechanic told me, and everyone after has said it isnt.

also when i was in the capital i went to the mazda dealership and asked about the cost for a new fuel presure regulator, and the parts dept told me that the year of my car predates the models that are equipped with this?

i dont want the ride im on going on for ever.

bkey71 and sstlaure
thanks for any info or suggestions
sincerely jhons mazda

 

might be possible that the oxygen sensor needs to be cleaned or replaced

 

A timing belt off by 1 tooth can not cause it to run rich...it just would not run correctly at all.

I do not see how an ECU can cause it to just start running rich either. An ECU just responds to it's inputs. It might not hurt trying to replace the coolant temp sensor. It is fairly inexpensive. It is located on the thermostat housing.

If your car is fuel injected, it must have a fuel pressure regualtor. It is located on the fuel injector rail and has a vacuum hose connected to it. Here is a LINK to see what it looks like.