Bambam7

Ok, this I don't understand....
I have a 90 GXL, and to check the engine codes you ground the "initial set" connector under the hood, then the check engine light flashes codes.
Also, you are supposed to ground the connector before setting the timing and a few other things (idle, ...)
OK, I was checking for codes becuase my car was running like crap, kindof rough. Anyways, I forgot to unplug the connector, and started the car and drove off. 2 seconds into driving I noticed a huge improvement in power and smoothness. All the roughness was gone. I also just had to drive for a few hours to a few different towns today.... and I noticed another startling difference- My MPG has more than DOUBLED!! Up untill today, I would get about 150 KM for 20$ (Can.) -half tank- of gas, pretty bad.... I have 190km so far and have burned slightly more than a 1/4 tank!!! The car feels brand new (except I blew a tire...)
Does anyone know how the initial set connector afects the ECU?? Does it put it into a failsafe mode that ignore sensor inputs?? (Which could be bad on my car... makes sense..)
Well, I'm leaving it hooked up, I don't car if my check engine light keeps flashing! (My ACV is gone so I always have a code 30 and 33)
Also- I have a code for my fuel pump relay.. where the hell is it and what could be wrong?
Later!

NathanRX7

Did you lose power?

Node

iTrader: (1)

I'd be careful if I were you
if you get double your fuel mileage
you're probly getting 1/2 as much fuel
which might be you leaning out for some reason
be careful until someone gives you an answer as to why

The Ace

You were running rich, and now you are running lean ? Maybe....or you were running rich ALL THE TIME, and now you are not ? Also maybe....

The fuel pump relay ? Must be the little thingie under the filter box (or is the one in the trunk, right above the tool-box ?). One of these two anyway...

Node

iTrader: (1)

lol fuel pump is in back of hatch so hmmmmmmmm, i dunno if the relay is at that end of the wires or not
oh well
GO DIGGGIN!!!

Rxmfn7

iTrader: (4)

Uhm, I think Ace was talking about a little yellow conector on the passenger side under the hood. If you bridge this with a wire it runs the fuel pump, it is like a bypass relay or something.

tesla042

Is there an equivilant for the 86-88's?

-Tesla

Bambam7

Update- I disconnected the wire, and my car is still running terrific. It feels more powerfull to. I guess I did loses a tiny bit of power with the wire grounded, but that is only compared with the way it is running now... before it was so bad with the roughness and stuttering that anything was an improvement. It felt like my secondaries were clicking on and off, a rough ride, aNd random stuttering w/inconsistant power above 4000 RPMS.
Also- I am getting a pressure sensor signal- I hooked the sensor right up to a main vacuum line because I removed my ACV valve... why would I be getting a code for that??
I have determined that everytime I reset my compter, It runs fantastic for a while.... then slowly goes downhill. I am at a loss why. I know I need a new TPS (spikey) but I guess I'll break out the manual and start testing EVERYHTING!
I love the mileage though.... 290 KM on a a good chunk less than half a tank.... literally more than doubled. Lets see if it stays that way after resetting the ECU and having the wrire off......

red7

Where is this wire located, the Hayes manual don't mention it. Also is it the same one for setting the timing and checking codes?

tesla042

I looked thru the FSM for my 88.. It mentions it, but it doesn't say how to use it.. It's up near the battery.. Right near the leading coil. I'm not sure if I directly short the wires, or if I put a resistor between them.. I'm hesitant to do either until someone mentions which to do..

go_speed_go

Every time you reset the ECU, it returns to the normal fuel/ignition maps. As the ECU detects error codes, it will make adjustments to compensate for the error in an effort to prevent engine damage. As you set off more codes, your car is bound to run worse.

10TH_ANNIV_T2

The 1988 FSM, Page 4B-7 explains the purpose of the Initial Set coupler, Page 4B-80 through 82 address Idle Speed and Mixture adjustments, showing when you use the Initial Set coupler. Page 4B-73 shows the location and testing procedure for the fuel pump resistor relay.

Yes, the set coupler bypass is effectively just a short, and it's use is short term. Maybe Six Rotors will respond, he appears to be a Mazda tech up in Canada-- a pretty helpful person to me.

I'm not able to send images of these pages now, but if anyone wants/needs them or the similar procedures from section 4A (non-turbo) just send me a PM. I'll try to get them out tonight.

Greg O.