Adam

I have an 88gxl . so yes i have an s4

Adam

Thanks hailer for taking the time to post that control unit/Monotor unit. That is exactly what i would like to use to check everything with out being under the hood checking everything sepratly... Now where can i find one of those. to rent or buy. cant be cheap.... and also are they for use with rx7's

Rx-7Doctor

iTrader: (13)

Soinds like you may have multiple problems. Correct about the coolant temp sensor
one of the most critical when it comes to fuel. EAsy test to do by back probing the
ecu for correct values. Recomend that you just buy multimeter they are inexpensive and effective. How is the idle? Has this problem been going on for awhile? If this has and your running rich, it is possible that the cat is plugged and
damaged. Any exhaust shop can check this (if you are running stock exhaust).
As far as the o'2 sensor goes, not much function on our cars until actual cruising but you would not notice a running problem. Check to make sure all the main fuses are in order and if you have a timing light make sure you have a good signal to both leading and trailing sides. rx7doctor There is alot more testing involved but this is the basics and dont forget a compression test on the power loss
problem also.

casio

that is from our FSM, so it would be rather misleading if it couldn't be used. it looks to be rather universal. it splices into the ecu (wiring harness) wires and gives voltage readings that the ecu is seeing.
as far as difficulty checking wires, that thing seems to be a tad more difficult in a sense. you have to splice into each ecu wire that has a voltage that you'd need to see. installing an safc is enough sitting and splicing for me. in order to do all those wires, i'd want the harness out of the car. unattaching the whole wiring harness would not be fun.
and you really shouldn't be "under the hood" all too much. you need to be testing at the ecu. if you're getting a bad (irregular) signal at the ecu, then you should be looking under the hood at possibly why you're getting a bad signal.
as cool as that device looks, i bet its a pain to hook up. great in the long run, though. in order to install it, my harness would be on a table, not in my car.

PS: the tester says "mazda" on it. still looks rather universal. all i see it does is shows a voltage from a selected pin.

HAILERS

OOOPs. Your misreading me. That outfit I jpg'd is not anymore useful than a digital meter from Radio Shack and shoving the meters probes up the aft side of the ECU plugs and taking a reading. It's just a meter with a switch. Turn the switch and the meter reads the output of a wire. Turn the switch again and it reads the next wire. It can't tell you if the reading is good/bad. That is left to the operator and his FSM. You can buy one from Mazda, but I'd think it would cost over a grand. No value for the money to be had there.

Mr Casio....I mislead you a touch. My breakout box is not built with the rotary switch. Just a set of three female plugs breaking out of my self made harness that sit next to the driver. I just stab my meter into which socket I'm interested in and read the meter.

Adam....should make himself that *code breaker* that is on this site for S4 cars. That's a begining, but not a final solution. As I might have said earlier, it will give you a code. Maybe you'll get a code that says *Pressure Sensor*. Now you have to see if the sensor is disconnected. Not disconnected? Then you now have to see if the Sensors output is getting to the ECU. You do this by backprobing the proper pin in the ECU plug. No output signal? Now you have to see if the Pressure Sensor is getting its 5v Ref voltage. Got that? Well does it have a good ground? Got that? How about the 12v that goes to it for the IC inside it?

Wayne....*the leaking EGR man*, wrote a thread about accessing the ECU plugs and using the FSM to determine if things were Good/Bad. You might read that.

More or less. looking for your fuel consumption problem? THE NZ mentioned one of the most likely suspects. Its on the back of the water pump housing. Green in color. The most likely in my opinion is .......lowwwwwww compression. Maybe scrogged up timing as the next. Emissions don't cause bad fuel milage unless the catalytic converter is old and clogged up.

Actually the Pressure Sensor could be a cause of bad milage. If the vac hose is off the secondaries will come online ANY TIME you exceed 3500rpm. Whereas usually they only come online when over 3500 AND the engine sees a load via the pressure sensor/afm/someother items.

If I were you....I'd visit RadioShack and buy a Digital Meter for around twenty-thirty bucks....download the Fuel section of the free online FSM....go to Control Unit in that section, and have a go at it. Don't use a meter much? Not a biggie. It's hard to destroy a digital meter and they have instructions. Gotta start somewhere/sometime. Like me and this STUPID new laptop. Hitting all the wrong keys........sensitive mouse beyond belief......has no serial port only those USB so I have to buy an adapter for $$$$$$$$. Got it incase I buy a PICO scope. Gotta have toys. He who has the most toys when he dies.....WINS! g
.

Adam

reply to rx7 doctor

The car runs fine at idle and cruise.. No missing at all.. Just a lack of power. and low miles to the gallon.. just in the summer i was getting 230-250 for a tank (16) or so gallons.. that fell al the way to 160 or less..all i did was change a thermostat. Didnt do much to it all all. ill get a muilty meter and check some stuff soon as i can. also had some problems with this green plug on the top near the thermostat. its a sensor that is at the top.. Not sure if its working or not.. the things sorta spins. Not sure if thats telling the ecu anything or not. what do they read at cold and warm. anyone know? thanks

Adam

Ok cool.. ill start with pulling codes...can there be codes there without the engine light on?

Adam

I read on how to get codes.. but still not sure of everything...is it saying to just put an LED light in DCC1 and one in DCC2.. thats it..or is there more to it.. I cant understand some of it

casio

i dont think i ever commented about the breakout box. i've never seen one and know nothing about them.
i'd thought about something similar to that box you posted the picture of, but a completely different setup. instead, my setup would consist of splicing into the wires like that picture showed, but going into a small box in the center console. it would have either buttons or a rotary dial to choose which wire (pin/sensor) i wanted to see the voltage of. i would prefer either round analog guages or digital. yes, plural. i would want at least two gauges so i could see 2 sensors' output. the reason i wouldnt want a rotary dial to choose the sensors is because that would mean i couldnt choose any two sensors at any time. i would have half to choose with one dial and half with the other.

casio

is it the plug thats under the alternator? on the back of the water pump housing? its the only green plug i can think of (on my S5 anyways). if its what i'm thinking of, its your water thermosensor; very vital. i believe it was already mentioned once in this thread. make sure its plugged in.

NZConvertible

The reader is a Mazda tool used for numerous Mazda ECU's. FYI, that reader was also used for the B2200, 323, 626 and 929 (I have the 1987 Mazda Special Service Tools manual ), so these cars must've used different versions of the same ECU.

It doesn't splice in, it plugs in. Splicing means to physically join the wires together.

As above, all you do is plug it inline with the ECU and it's harness, then flick the **** to the pin you wanted to read. Doesn't get much easier.

Adam, given that these ECU readers would be very difficult and probably very expensive to obtain (don't even consider hiring), using a cheap DMM is by far the quickest, cheapest and easiest way to read the ECU signals. In fact if you read the S5 FSM it tells you to do exactly that. No reader is used.

Adam

the gree n Plug? not the one behind the alt.. the one im talkin about is in the thermostat housing. on my (s4)..BTW i was over looking my gauges and i dont have an check engine light!!! anyone have an S4 with a check engine light?

casio

sorry, i completely ignored the fact that it had an adaptor harness. whoops!

HAILERS

If the Water Thermo Sensor shown in the jpg below spins.....it's broken and you NEED another.

The LED arrangement is shown in the jpg also. Cost is about four bucks. You join the two red wires together and put a spade connector on them. Then put a spade connector on each of the other two wires *yellow*. Then install them in the green, six socket connector near the Lead Coil assy on a series four non turbo.

About the install of the LED'S. Look directly into the six socket plug. Put one yellow wire in the top left socket. Put the other just below it. Put the red LED wire in the top row, second socket from your left.

Turn the key to ON. The two lights WILL come on for about three seconds, then go out if there are no codes. If the lights blink, read the article and determine what the code represents.

If no lights light up after coming on for three seconds.....then pull the electrical plug off the boost sensor. The lights should now blink a code. Or pull the plug off the tps. A code should result. Reinstall the plug and the code should disappear.

NZConvertible

That's what I said...

Only S5's have a CEL. You need to make a code reader like Hailer said.

Adam

great info... thanks.. and i will get back to you after i get any more news on the light readings.

Adam

LEDS Hooked up to ECU key turned on booth lights come on then they go back out? red is to the right of dcc1 the black is in dcc1 the other black is in dcc2.. i turn the key on and both lights light up.. then go out.. DO i not have any codes then???

Adam

Now im getting One Long Blink.. then a short blink..(s4). any idears

HAILERS

http://fc3spro.com/TECH/HOWTO/ERRORC...KI/zerror.html

Read that site. The codes are at the bottom. It depends which light is doing the blinking. DCC1 or DCC2.

Like the article says, the two lights will come on for about 3 seconds then go out when you first turn the key to ON.

If DCC1 is the blinker...it sounds like its indicating the TPS is out of range. Or disconnected. Or????????

Adam

ok that helps ill save that page this time...... yes it was Dcc1 blinkin.. I removed the plug too the tps to see if i got a reading on it sure enough...I plug it in.. reset the computer..And both lights come on. for three seconds then go out... so i guess there is nothing else wrong... Darn.. i was hopin to find somthing....these lights are hella handy..i think im going to wire them in to the cockpit long term so i can keep an eye on everything...thanks bro