Cold Start Issues

[fixkick]

24s will limit horse power, ecu cant know speed so, its limited.
some ECU get more upset, for lack of vss.
the ecu has a starter pin, that tells the ECU that you are cranking, if that is missing the ECU cant know to compensate for low rpm cranking, and needs that.
it also opens the ISC up for more air cranking for the same reasons, low rpm.

the ECU has many pins that can be wrong, related to this.
16v list.
http://www.fixkick.com/IDLE-AIR/fastfix.html#ecu-hosed

[Malcolm]

Perfect. I suspected it still wasn't 100% right.

Just so I understand. Reading your ECM connector chart it shows crank signal as A2 and it appears it's a system voltage input. Does that mean I can just feed it off the same 12v that I feed to the starter solenoid? I just want to make sure I'm reading the language the right way so I don't fry the ECM.

Code 24 means I have hp left on the table then? I'll head down and pick up a VSS out of a sidekick. There appears to be a few write ups on this. I'll get that taken care of.

Thanks again

[fixkick]

a2 is the (the start/crank ) pin, this pin goes hot, cranking, from the spring loaded, cranking position of the key switch.
no, the table there is very simple.
to see who it real works , see my schematic page. see A2? (off schematics page)
http://www.fixkick.com/ECU/92-95MPI-eng-...e-huge.png

see a2, its 0v keyoff or on, then, 12vdc cranking, and 0v when you release the key, its the same wire and same color that goes to starter solenoid, (tiny lug)
sorry, the ECU runs off sensor inputs, to do spark advance and fuel rates.
the fuel rates are run at 02 sensed levels. . called STOICH. 14.7:1 air to fuel ration, at cruise. but...
the acceleration rates (the 02 drops off line) and the ecu uses MAF, RPM and load calculations.
there are tables (many other too) (computer tables i memory ) for load.
based one engine sizes, car body weight. and load is calculated by SPEED and air flow into engine (maf) the ECU injects fuel. by many factors.
The VSS does help the engine make more power, going fast and up hills.
the vss , is just reed switch clicker in the speedo. (magnetically tripped)
see speedometer sensor. next (its just a reed relay , seen here.) so many clicks per mile.

here it is , back side of SPEED head.
showing the vss , being slid out.

---

on new cars the Vss is a transmission tail shaft, hall sensor
on my car, the ecu steals speed from ABS sensors. ( no actual vss exists on my new 6 speed m/t car) wow....

summit racing sells them in kits at crazy prices.
or get the newer sammi head that had EFI. 1990 to 1998 (last ever)

---

in your car, new , long ago.
the a2 pin is the clutch , is depressed now, and cranking pin signal.
id bet your clutch switch is missing, so is now just a cranking signal.

[Malcolm]

In an effort to help those facing similar issues in the future and thank you for all of your guidance I'm happy to report that I've run 100 miles now with no error codes since installing a homemade VSS switch (using a reed switch) and all of my starting issues irregardless of the outside temperature have disappeared since I hooked up my crank (starting, not actual crank position sensor) signal wire. Thanks.

Here was the maiden voyage with my bother and his 1996 Tracker for Christmas trees this year..
   
   

I have noticed some occasional slight low speed hesitations since installing the VSS, does this seem normal? I know its being fed from a lower geared T-Case which along with slightly larger tires (not big enough to equalize one another) which should have an effect on true speed vs whats being reported to the ECU?

Thank you again for all the help and Merry Christmas!

[fixkick]

vss only adds power driving, id dont click parked, working or not.
if the speedo read ok,so does the licker, and odometer.
what crank sensor?
1994 ECU, has no crank sensor , and my guess is harness on car is 1994 !
cam sensors is in the base of the distributor.
vss is in cluster as you know know.

that is it for all rotory sensors.

x10 that Merry Chrismas !!!!