i got a 94 eg coupe the problem is the car isnt getting any spark i have tested the icm ignition coil all the distribtor components crank sensor etc i cant track the problem is there a way of finding out if the ecu/ecm is bad i tried pulling the code the light comes on and will not come off somebody please help its my daily driver i also pulled the computer out and put it back in help please

 

Is the fuel pump priming?

Retrieve the CEL as detailed at the link in my signature.

Is the distributor getting battery power at the distributor connector when the ignition key is turned to ON (II)?

Check whether the important ground wire on the thermostat housing is connected and not corroded.

Check whether the ECU fuse #31 (15A) under the hood or the alternator/main relay fuse #24 (15A) under the dash is blown.

 

i checked all the fuses under the hood and under the dash they all check out and are getting signal the problem lies between the ignition input signal and the ecm im not sure what the voltage between the to is supposed to be do anybody know the voltage spec?

 

I think the input test is for continuity of the YEL/GRN wire (ECU to igniter) not voltage.

Test whether the CEL turns OFF when you disconnect the 3P connector of each sensor one at a time:
MAP sensor
EGR valve lift sensor
Throttle angle sensor


If not, could be bad wires between these sensors and the ECU or a bad ECU.

In addition to lacking spark, does the fuel pump also fail to prime?

 

It sounds like your ECU is responding normally. With the test wire off the CEL should come on and go off when you turn the key but don't crank. With the test wire on, it should come on and either blink out a code, or stay on steady if there are no codes stored. If the light does this the ECU is powering up and working to some degree.

Does the distributor rotor turn when you crank? Could have a stripped timing belt.

Testing coils with an ohmmeter gives a lot of false "good" results. Test for sparks at the output of the coil. Remove the cap and hold a grounded wire near the output spring and crank the engine. Sparks should jump 3/4 inch or more. If you get only small sparks the coil is bad. If you have no sparks at all make sure that power is reaching the distributor (small terminals on coil should both have 12 volts to ground) with the key on.

 

it doesnt get spark or fuel on its own i have to tap into the relay and put a switch on so i can manually turn the fuel pump on and the timing belts cool i checked all the components of the diributor with a meter they all tested according to spec

 

Common reasons for lack of both spark and fuel (not ruled out by your responses):

1) Disconnected or corroded ground wire on thermostat housing.

2) Malfunction in circuit between ECU and MAP sensor, due either to bad ECU or bad wire between ECU and MAP sensor. Be sure also to check whether disconnecting the MAP sensor (or TPS or EGR valve) causes the CEL to turn OFF.

 

So with the test wire off, the CEL comes on steady when you key on but don't crank? That is probably a bad ECU if it isn't the main relay. Make sure that all power and ground pins on the ECU are powered and grounded respectively.

I would think that if it didn't like the MAP sensor reading, it would blink a MAP code with the test wire on, not stay on steady.

Another test you can do is see if the ECU is feeding the 5 volt power to the MAP and TPS, if not it's a bad ECU or short in the sensor wiring.

 

the ground is good im gonna check the sensors and see how that goes

 

i finally figured it out i checked the senors and they were dead so i checked the main fuse box to ecm it wasnt distributing power to the ecm therefore making the main fusebox bad