Whats my engine? / Other probs...

Hey all, I have a 1994 Geo Metro, I've had it for two years and love it!
I have done some basic maintenance to it, plugs, wires, tie rods, water pump, and a timing belt.

I am currently having problems with the EGR system. I have taken out the EGR Valve and cleaned it out. I had to literally dig out the carbon! I have got it back together now, but the error code still comes up with the EGR... (Yes, I have cleared the codes - Battery / tail light fuse)
You can see the EGR operate while applying throttle to the car... ??

Also I have lost quite abit of milage with the car lately... used to get about 40-41mpg but its dropped to about 32mpg now. How much will the EGR affect the milage?
And with the EGR being all carbon'd up, how will the O2 sensor be affected? (a carbon'd O2 sensor will reduce the mpg aswell?) The O2 sensor is not reporting an error.
Which leads me to my final question... This 1994 Geo has a different year engine in it, I thought it was a '93 after the timing belt blew on it, but the O2 sensor listed for a '93 engine is a single wire sensor. The sensor installed on the car has 4?! (2 blacks, a blue and a white)

Where can I find out the model of the engine? and when it comes to the O2 sensor, can a single wire O2 sensor be installed?
The cost of a single wire sensor is $45 and the 3 wire sensor is $165 (So where did the 4th wire come from?!)

Thanx for your time.
Mogal

Yours emission system is the upgraded one with the 4 wire O2 sensor they were built even in 93 but the 4 wire one was sold primarily in California with upgraded emission system, starting with 94 they were sold in all states.
The 4 wire O2 sensor is the preheated type that means it has a small heating resistor in it to heat it to the ideal temperature for O2 to work that was done to reduce the emmisions during cold engine start up.
The single wire is the simple version and was kicking in after the sensor was heated by the exaust gases till then the computer runs in a loop kind of geting what it needs from the other sensors.

Some good info, thanx!

So you think its still a '93 engine, ok.
I'll look into a '94 o2 sensor and see what they got...
where is the engine model number located? on the block?

Think the o2 sensor is worth it to change out? Its not reading an error, but the gas milage has really dropped lately... and if its a heated o2, its 165 bucks... (but that was a 3 wire one)

Cheers,
Mogal

OMG !!

I just got off the phone with the dealership (cuz there is no after market part) The 4 wire O2 sensor, which is a stricter California emission O2 sensor, is worth an OUTSTANDING PRICE OF $522.75 Plus taxes!!!!

So going on that, I need to put in the single wire...
or at the most the three wire ($165)

Is this possible?
if its just a heater in the O2 sensor, I should be able to bypass the heater wires right? will that affect the computer/performance/milage?

Oh, some one please help... for being a cheap car, its not quite so cheap! :(

Cheers,
Mogal

What the Hell is this business with New Metro Parts costing so
damned much?

When these dealership parts department guys tell you some
absolutely necessary sensor costs more than the car's current value,
I have the desire to reach over the counter and punch them in the face - HARD!

Is this a new thing, now?

Raise the parts costs to assinine levels so as to make folks junk
the older cars and buy new ones?

I had a discussion with a Schucks parts fellow about buying
used MAP Sensors. He swore I was foolish to buy "That Crap."

So I had him look up the cost of a new one on his computer.

$340......... I just stared at him. Jerk!

I would love to see a new manufacturer appear that supported
its products with parts at a really reasonable rate.

I would assume that such a manufacturer would outsell all its
competition eventually. Ya - right! I bought shares in the
Brooklyn Bridge last week, so maybe I should shut up....

BTW - have you ever added up all the costs of your vehicle
and seen just what percentage of your net take home pay you
spend on your automobile(s)?

I mean Upkeep, tires, repair, Gasoline, State & Local Taxes plus
Insurance - include payments if you don't own it. Testing fees?
Tollway & Bridge charges to get to work? Parking Fees & stickers?
I'll bet you'd dump in your pants!

Is it around 10-20%?! Do you have two or three cars?
Some States Tax the crap out of car ownership.
Just to get to work so you can pay for that Money Pit.......

'Don't worry - be happy!....tra la, tra la...."

DoctorBill

Yea, I fully agree with yea Doc.

I remember a news cast about 20 years ago that a $20,000 car would cost $100,000 if yea bought the parts individually from the dealer.
I'm sure that raitio still stands today, or is even worse.

On a happier note, I have managed to track down a new 4 wire O2 sensor for $138 !! WooHoo! from a smaller parts dealer around town here.
Dunno how these guys managed to pull off the price, but I have it on order, should be here in the next day or two. Still more then I wanted to pay, but better then the dealership.

I have the EGR working correctly now, and the engine light is out and hasn't come back on... yet! :) car seems to be running great...
I ended up soaking the EGR valve and the modulator in varsal overnight. Were shiney and new by morning!

I calculated the last tank of gas, and I got 37mpg on it. I'm hoping the new O2 will bring it back up to at least 45ish... ??

Damn, the engine light came back on! err...
I think its the EGR modulator... I'll post back later when I get some time.

Cheers,
Mogal

Dude just get a used 4 wire O2 sensor .
And yes you can use a single wire but hmmm I have to charge you for the trick..... :evillol:
But today I am in the giving mood Lol
Now I don t remember witch wires are for the heating resistor but you can find out from the Chilton manual.
The trick is to fool the ECM that you have a heating resistor if you don t and you will use a single wire the ECM will post a bad O2 code because will think that the heating resistor is burned out and will render the O2 useless.
Now after you find out witch 2 wires go to the heating element take an Ohmeter and measure the resistance value of the heating resistor, go to Radio Shack and buy a resistor of that value and medium wattage and connect the terminals to the wires witch come from the ECM.
After this is simple, one wire will go to the lead wire of the single wire O2 sensor the other one to the ground.
Take care hope I didn t forget anything.

Well, I guess the Modulator is/was shot.
I got a new one($90) I tried everything to get the old one working again, I think the spring is shot inside.
I also picked up a new O2 sensor, $135... but I haven't installed it yet.

I thought of the resister/single wire O2, or a used one, but no garenties with either setup... so for $135, its ok... beats the fricken dealer!

My milage has dropped drastically in the last couple of tanks... (around 30mpg now) used to be over 41+... these things are rated for 50+ right?

I've changed the plugs wires, air filter, set the timing (5 deg BTDP as per under the hood) New water pump, corrected tire psi... fuel injection cleaner (anyone ever find that when they use the injection cleaner, milage drops with that tank?) Fuel filter is a year old, points and cap are a year old... oh and I thru a bottle of carbon cleaner down its throat...

The car purrs pretty good, no hesitation, the power in the car seems good (lol... for a 3 banger!) There was/is alot of carbon build up, and thus why I want to change out the O2 sensor... Maybe the O2 (although reporting no error) maybe starting to fail.

Anything else I could check? I don't have a compression tester.

Cheers,
Mogal

P.S. I'm still not 100% sure what engine I have, could it be a suzuki engine?

All the engines are made by Suzuki.

err... error code 51 again...
After 2 days, and about 100kms...
(Still haven't changed the O2 seonsor yet)

You can see the EGR valve operate(car at idle, and you throttle the engine)
So the system 'seems' to work ok...

Hey Doc, do you have a picture of the coolant sensor and vacuum sensor?

I have found this most impressive PDF on the EGR system:
http://www.autoshop101.com/forms/h61.pdf
As per page 5 of that document, EGR Fault detection system, is there an exhaust gas temp sensor on this car? Doc? :p

Tomorrow at work, I'm going to put the EGR valve throu a sonic bath...

Any suggestions guys?

Thanx..
Mogal

Well, after lots of reading, and a little more poking around the car, I have finally fixed (for sure this time) the EGR problem!

There was a carbon build up deep inside the intake manifold. The exhaust return into the intake (the return port from the EGR valve)

I removed the EGR and used a can of carbon cleaner with some pipe cleaners... dug at the carbon, the sprayed the cleaner into the port to expell the loosed carbon. Worked well but took some time...
I ended up starting the engine with the EGR valve removed while diging and spraying the cleaner... the last little bit of carbon got sucked into the engine when the clog finally cleared... :eek:
So I sprayed a little more (ok, ALOT more) carbon cleaner into the port to help dissolve the carbon ASAP :rolleyes: had to operate the throttle while doing so because of the now broken vaccum....

Shut down the car, and sprayed a little more cleaner into the port before I bolted everything back together and reset the computer.

The car is running ALOT better then before... idles smoother now, has more power, better response and I'm sure I'll get better milage now...

Those of you who claim the EGR system is not worth fixing, I have to dissagree after my experiance... the EGR has made a huge difference now that its functioning properly again...

I will update again after a few tanks of gas...

P.S. still haven't changed out the O2 sensor... If the milage doesn't improve now that the EGR is working, I'll change it out.