today i decided to follow both the grounding DIY's in the archives, grounding the pressure (boost) sensor, trailing and leading coils, ecu with 10 gauge and two additional grounds with 2 gauge wire as prescribed in IRISHMAN's "super grounding" post, on my 89 GXL.

after i made sure all the connections were nice and snug, i tried starting it.....it turns over, but does not want to fire up. and this is where i am stuck - in the process, two sensors wires, the temp. sender gauge (beside the oil pressure sender) and the oil pressure condenser were torn by accident. although i do not think that would contribute to my no start

even after taking off all the grounds, it still doesnt start

what could be wrong? did i wreck my car?

 

As wayne has said many times dont ground the pressure sensor.
How did you ground the ecu?
Double check every connection, esp AFM, CAS, and any ecu connections you touched.

 

i grounded the ecu by soldering a 10 gauge wire to 3C on the ecu layout, which the service manual describes as constant ground, then attaching the other end to a ring connector, and securing it to the ecu cover plate

i'll check the connections again, but i didnt go anywhere else with the ecu wires except that one

thanks for the quick response, i hope i get this fixed tonight

 

Maybe Wayne should call MAZDA CORP and tell them to withdraw their factory service bulletin put out in 1987, to ground the boost/pressure sensor to the water filler neck. See ALLDATA.com for the service bulletin number. Only the early series four should need the extra grounding point.

Now describe the wire on the boost/pressure sensor that you grounded. What was the color of the wire?

 

it was brown with a black stripe, the only one out of 3 wires that had less than .3 volts with the key in the on position

the only thing i could think of in my situation is the sensors not reading, therefore not allowing the engine to start, or incorrect grounding, which is unlikely at this point

 

The car will run without the sensor connected. Go back and see if you have approx 5vdc onf the brown/white wire on that sensor. No approx 5vdc equals a car that ain't a gonna ever start.

And what was the color of the 3C wire??? Just fishing.

 

the 3c wire was black i believe, with red bands around it...

and the brown/white wire has 5vdc with the ignition on, the ground and the other wire do not have any voltage

would removing all the grounds start the car again?

 

No. The car should have started. But if you had grounded the brown/white wire at the boost/pressure sensor, that would have fried the dodad that puts out the reference voltage internal to the ECU and you would not get any spark a'tall.

Do the ole thing of putting a sparkplug wire near one of the left strut tower bolts/studs and cranking the engine and look for spark. Got sparK? Maybe its a fuel issue. I've no reason to think so though. Can you hear the fuel pump when the fuel pump check connector is jumpered and the key is to ON?

Or go take a look and see if your ENGINE FUSE is fried. It's inside the car. Left foot area.

Flooded????? Series five? Depress the pedal all the way and crank the engine til it starts.

 

s5, its not flooded, that's for sure
it was running fine before all i put these wires on, after that, wont start

i'm gonna go out and check the fuse, and everything else
maybe i can find something out of wack

EDIT: found a 20 fuse in the bottom left of the panel that was blown (EDIT: its the audio one....crap.)

 

re-checked everything, connections are all there

i guess i'll try replacing the sensors, maybe that might work...my engine doesnt like to be incomplete in anyway...my car wont start if any BAC/air pump/intake hoses are off the car

 

one more thing, does the oil pressure condensor and temp sender contribute to engine startup at all?

 

None whatsoever.

Check for spark. The fuse box fuses are shown in the FAQ thread at the very beginning of this site. The picture is about halfway down that FAQ thread.

If the plugs are on the ECU and no hose was left off, it should have started. Check for spark.

Also check the fuses in the ENGINE BAY. Make sure alll of them are good, especially the two most inboard. The EGI Inject and EGI COMP