got spark but engine wont run

[paintballer999]

I was having issues with the cas not receiving power, but i found out that if i hook the cas to a power source and not the harness it works and allows the coil pack to receive power and the spark plugs now spark. is there a test to see if there is a signal being sent back from the cas to the computer through the white and yellow wires? also, i did hook up the cas to the harness and i tapped into the wire to give it power. when i gave it power i heard a clicking from the top right of the engine. what could that be? as for the injectors, how can i test that fuel is running through them, or that they are truly spraying into the block. thanks in advance for the help

 

[steve]

Start by checking he ECU. It should have been turning on the power to the CAS via the MPI relay.

 

[obsidian]

I had this same issue. The plug the CAS goes into was my culprit, check the wires there and make sure everything is as tight as it can be.

 

[paintballer999]

i checked the cas wire to the harness, it is connected. but i replaced the mpi relay with a working one ( the little box by the computer) also there still seems to be no power to the cas. what might be the issue? is the computer the thing to blame?

 

[stars]

The CAS has 4 wires that feed voltage from the MPI relay on the Red wire (12 Volts) Pin #3. On the CAS there are 4 wires correct? Black (5volts) Pin#2 and White(5volts) Pin#1 these 2 feeds the ecu. Pin #4 is also Black but, it goes to GROUND. Check voltage when ignition key is "On". If you have no power there backtrack Red wire from the CAS all the way back to the MPI relay, check voltage on the Red wire, if No voltage, then go to ECU itself. The ECU is what supplies power to MPI relay. Pin #107 on the ECU should have 12 volts, if it does NOT then replace the ECU.

 

[98_gsx_]

Check fuel, and your ECU

 

[steve]

When you turn on the ignition does the CEL turn on for five seconds and then turn off?
Does the factory boost gauge move to zero?

 

[paintballer999]

ok, as for the info i know about the car and my speculations, it was bought by someone else with the intentions of taking a talon tsi and installing all of the pieces from one car to another. the tachometer does not include a boost gauge, so i installed one. i tapped into the fpr line from the intake. as for the CEL, it does not come on, or blink. i have never seen it. a yellow light on the dash that looks like a radiator is on, also a red light with an oil can is on. i know there is oil and coolant in the car because i built it from the bottom up. i bought the car as a project and i was at the end and wanted to see my work being complete when i turned the engine on. to my surprise, the engine turns over with no spark but the fuel rail does build up pressure, but i am not sure if the injectors are squirting. does the mpi relay send the signal to the injectors? so if my ECU is shot, would it prevent power from being sent to the CAS, injectors and spark plugs? sorry for the long response but now everything is truly oout there for anyone who has a thought to throw out there as a possible solution.

 

[steve]

The fuel pump is turned on one of two ways, by the starter circuit while cranking and when the ECU see CAS pulses. Since your CAS isn't getting power that rules out one.

The MPI relay is turned on by the ECU when it sees 12v from the ignition switch on ECU pin 110. To do so it needs the backup power on pin 103 to power the circuit watching the ignition. The ECU pulls pin 63 to ground to activate the MPI relay. The MPI relay gets it's power from the MPI fuse on the positive battery terminal on the big black/red wire to the relay. When it's active it feeds 12v to the ECU pins 102 and 107 and to the CAS, Injectors, solenoids, MAF, and ISC.

Since your cluster isn't for a turbo car it's hard to say at this point if the CEL not turning on is because of the ECU being bad, the MPI fuse being bad, the MPI relay being bad, or something else.
You'll need a voltmeter (and the FSM) for the rest of the tests.

 

[paintballer999]

ok, i think i have found the culprit. the ecu looks to be damaged after a closer look. it has a faint smell of capacitor acid so i will be sending it out to ecmtuning, or some company like that. i saw it in other posts from dsm wiseman and others of that sort so i assume it would be a reliable place to send it. thank you everyone who has posted , it has truly helped out a lot.