94 tracker still won't fire

[wmpownell]

I have tried a new Module (ignitor), Coil, Distributor (Dizzy), and had my ECU repaired by digitalguy on ebay. What next???? No fire from coil. Digitalguy said to have Fuel injection relays tested. Nobody in my small town can test them.

[wmpownell]

It is a 1994 tracker--2 dr, convertible, 8 valve, automatic, 4 wheel drive

[jtgh]

new ecu, new ignitor.

fire, ? a are you testing with a test spark plug directly connected to the coil.
top High voltage tower terminal? (plug grounded ,no hands ok)

do you have a digital Multi meter, that can measure ohms.?

measure the coil ( unplugged) primary and secondary resistance.
primary: low ,like 10ohms ( i have spec) Brown/wht to blk/wht.
secondary : high like over 50,000 ohms. HV term to Blk./wht


on your car, the fuel pump relay can be removed and there WILL BE SPARK.
how ever ,the MAIN relay must be good.
it sits right next to FPrelay.
who to check that , that is easy. anyone can do it.
lets not try to test it, lets just see if it is doing its job. far easier.
see blue black wire there on the attached print.?
if you have 12vdc to any of those items listed, then the Relay is working.
check while cranking.

This proves you have full power. ( see dizzy power ,see a12 a13 on ecu)
btw , the fuel pump and relay get power from the MAIN relay.
so if the fule pump buzzes, you do have power. (cap off tank .listen)

if power is good
you then need to check both the CAS and the coil drive.

toss a coin.

there is only 3 ways to test this.
1: scope. ( you dont have it)
2: led and resistor .
3: throw parts and go broke. (sorry)

The CAS can be tested 3 ways:
scope, Meter VM and a LED/resistor.

it is possible to make spark with just a 3cent resistor in your hand.
one can unplug the ECU and place a resistor jumper and make spark.
just like in the old days of points dizzys

SPARK: (assuming power to ecu and associates)
CAS ,generate signal, goes to ECU , Ecu makes spark signal that drives the Ignitor which in turn drives the coil and spark happens.

its really just 4 parts, and some wire.
so when spark fails , the problem is the CAS (INPUT)
or the output of ECU is bad or the coil or ignitor are dead.

both sides can be tested and it only costs 10 cents if you have a DMM.

this problem can be diagnosed.

tell me more.

cheers

[wmpownell]

I am checking fire at coil with a dummy plug grounded to engine. The parts dept at GM dealership told me that my tracker doesn't have a CAS (CPS). Are they wrong or is what they are calling a stator in my dizzy really a CAS?

[jtgh]

hes is just playing word games.

all these 1.6L kicks 8v and 16v have real dizzy.

in the bottom of the dizzy is a CAS or cam angle sender.
in 89 this part is called CAS buy SUZ
later called CMP (95 manual calles it that, see DTC 42)
then ISO standards renamed it CAS.

this is a 1994 8v , it is called the camshaft position sensor in that year.

the stator is the metal star wheel that triggers the CMP.
the CMP is just a hall effect sender,.

I even have a full schematic of it. here.

http://carfix.stufftoread.com/IGN_ti...IZ-CAS1W86.jpg

it generates a 5v sqaure wave, it it is dead, there will never be spark.

it can be tested with a voltmeter ( and helper to crank) (fsm method)
or with an LED + 500-600 resistor .
or with a scope (or DSO)
it can be tested in or out of circuit.


It is possible too , to make the coil spark with the ECU unplugged.
both tests prove the outside of ECU parts are good and that the ECU is bad.

CMP:
using a back probe method
probe the signal out of dizzy.
as you crank it will toggle from 0v to 5v.

http://carfix.stufftoread.com/IGN_timing/CAS-91.jpg
actual scope view on a real 8v kick.


scope, led or meter, this one can be tested
but there is ONE trick,
you can not disconnect the DIZZY during the test.
the DIzzy needs power and ground to function and the output must have a pULL up
resistor ( the dizzy output only opens and closes and NEVER sources power)
this fools many people.
to test it on a bench,
connect power and ground to a 12vdc battery (any) and then connect the output
to a >>> plus lead(long) LED ,then LED to Neglead short> 500ohm resistor and then to +12vdc battery (same as battery pin +)
twist dizzy shaft,see LED blink.

the led test is close best because , simular current flows mimicing ECU.
but the scope is the best because its rubber meets road. No changes in circuit.

we can test it ,what you got for tools

cheers.

some later kicks use a fully integrated Dizzy , cap, coil ,cmp,ignitor. 96+ i think.
and yes, it can be tested the same way.

on the 8v ,it is just a TDC sender, to us humans.

[wmpownell]

I listened inside the gas tank for the fuel pump. No Noise. I checked with key on and cranking. No noise either position of key. Should I start by buying new relays.

I can borrow a digital multimeter, but don't know how to use it. I have a pretty complete set of mechanics tools otherwise.

[jtgh]

the main relay on side kicks.

how to test it .

location:
it is above your knees near the steering column and sits next to the green (91) socketed fuel pump relay.

it has 4 wire going to it:
i am making pin number here.

1- blu-white 12vdc key on
2- blue >>> ecu command to relay, 0v it must be key on.
3- blk-red >> 12vdc all the time
4- blu-black >>> 12 key on if not and above is correct then relay is bad or you have a grounded out main output bus, this can and does happen.

the main caps in the ECU can short out.


the Fuel pump or its feed can ground out. fuel pump do short out ! usually the ECU and main click like crazy.


now the meter:

it is best to have 1 meter and testleads normal and 1 set of aligator to aligator clip jumpers.

with the jumper you can clip on to the ground (ecu bracket and then use the red clip to hold a needle.)
i use a leather or upolstery needle

here are the steps.
meter , set it to 20volt range and attach leads to the banana jacks,
black to common, and red to the V/ohm + red jack. (not the 20 amp jack #3)

test the meter by testing a radio 9v dry cell, see 8.5 to 9.5 vdc. so now you are ready to test.

connect the ground to any shinny metal under the dash , the ecu mount there is a good spot.

find the Main relay there next the the fuel pump relay.
the FP relay has a green socket on mine and is next to the steering column. mid point.

how what ground attached, thru the key to on, and connect the needle so it is atteched to the red lead.
jam the needle into the back side of the main relay blue-white wire.

it must read 11.5 to 12.5v.
if not the relay is not closed.
next probe the other 3.
1= 12v
2= 0v
3- 12v
4- you just did it.


that is the whole test.

keep in mind you can have an open or a short in the system.

most common fail is chaffed wire.
#2 shorted fuel pump.
#3 some one wired some THING into the harness here and it is shorted, (aftermarket alarm?)\
#4 ecu has bad dried out capacitors and are shorted.

that is my help for this evening.
cheers.

[jtgh]

Fluke TP40 Automotive Back Probe Pins | Valuetronics

this are really cool, i dont have the but wish i did.

[wmpownell]

We have finally narrowed the problem down to the Fuel Injection Relay. I tore it apart and it is corroded and rusted inside. I resently pressure washed the inside of the tracker before I painted the floorboards. I must have gotten water in the relays (I'm an Idiot).

I want to thankyou for all your help and patience with me. I have never met anyone who is willing to help a perfect stranger as much as you have. You are a one of a kind. Your web site is very helpful. You are obviously very Knowledgeable about these Geo's. You are truely a good person.

[jtgh]

stick to dry matini's no water, no olives. and no pressure washing.

glad to help, i got to give back , life is good.