95 eclipse 420a no spark

Jayjay1985 · 08-05-2012, 06:31 PM

Need help. I got a 95 eclipse RS with the 420a to fix up for my wife. Got it with a blown timing belt. Repaired that and new head gasket tryed to start it and no spark. I replaced the plugs, cam position sensor, crank position sensor. The coil checks out good and I have tryed another one. At the coil plug I have 12 volts which pulses when the motor turns. In everything I have read it should have spark. I am going to try and swap the ECM tomorrow. Any suggestions?

iugrad92turbo · 08-05-2012, 06:34 PM

I would have checked the ecu first, and see what happens, let us know when you swap ecus.

AlbeUrDemise · 08-05-2012, 06:53 PM

If your getting 12 volts from the coil. You should be transfering power to the plugs... Did you replace the plug wires as well? Also check the Automatic Shutdown (ASD) relay. The Engine Computer turns the relay on when it gets pulses from the cam and crank sensors. So, check for voltage at the coil while a helper is cranking the engine again. You said you have voltage from the coil so if that is still correct, the Automatic Shutdown (ASD) relay is turning on, but if the crankshaft position sensor or the camshaft position sensor aren't working properly those signals are missing, the Engine Computer turns the ASD relay off and there will be no voltage to the coils, injectors, alternator field, and fuel pump. I hope this helps, but again check the ECU and let us know.

Jayjay1985 · 08-05-2012, 07:05 PM

The ASD relay is working and the plug wires are good. There are three wires going into the coil pack the center power wire has 12 volts which blinks on and off when turning the motor over. What do the outer two wires do?

AlbeUrDemise · 08-05-2012, 09:00 PM

I know the wires are set as 1/4trigger, 2/3trigger, and the common ground. I can't remember what colors are which though. I'm gonna look it up for you real fast.

Jayjay1985 · 08-06-2012, 03:46 PM

Tryed a different ECM still nothing

Could one one of the sensors short out and cause this? I have seen this on other posts. How would I check for a shorted sensor? I have tryed unplugging almost every sensor and trying it. I tryed grounding one of the outer wires on the coil plug and it sparks so I have come to the conclusion that it isn't getting the signal on these wires the 1/4 and 2/3 wires?

I'm about ready to smash this thing grrrrr

95TalonOwner · 08-07-2012, 09:51 AM

Double check the connection and connector at the speed sensor. Believe it or not, that is a common area that creates a no-spark condition. Also, make sure you didn't switch the coil/speed sensor plugs around when swapping things because they have the same connectors.

AlbeUrDemise · 08-07-2012, 09:54 AM

Quote:

Originally Posted by 95TalonOwner

Double check the connection and connector at the speed sensor. Believe it or not, that is a common area that creates a no-spark condition. Also, make sure you didn't switch the coil/speed sensor plugs around when swapping things because they have the same connectors.

I agree, double check your connectors. Sorry I haven't been able to post the specific wire colors I'm having trouble locating my book. Google tells me nothing so I'll keep looking for my book.

BoostedPhoenix · 08-07-2012, 10:30 AM

Quote:

Originally Posted by Jayjay1985

The ASD relay is working and the plug wires are good. There are three wires going into the coil pack the center power wire has 12 volts which blinks on and off when turning the motor over. What do the outer two wires do?

The 12v positive at the coil should not pulse when cranking, it should be constant 12v. The other two wires should pulse to ground while its cranking though.

Jayjay1985 · 08-07-2012, 11:37 AM

Ok I will check those plugs tonight, can they just be unplugged? My book says the 12v wire on the coil should pulse

Checked those plugs everything looks good. If it is one of the sensors will just unplugging it work or does It have to be jumppered out? I have a good ground on all my sensor plugs.

BoostedPhoenix · 08-07-2012, 02:12 PM

Then your book is very wrong, the middle pin should be constant 12v the ones on either side of it should pulse independently.

Unplug the coil, use a noid light to test between pin 1&2 then from pin 2&3 each should flash when cranking. But the middle should have 12v constant when testing to ground (engine or battery).

Jayjay1985 · 08-09-2012, 11:24 AM

Ok so I go the car running today. It's very strange. As a last resort I had read a post about a car that would only run with the cam switch upside down so I flipped my cam switch with the plug up and the car started right up and runs great. I have no idea y it works but it does. I rechecked my timing and cam sprockets thinking they were maby on backwards but they are not. Does anyone have any ideas y it would do this?

98talondb · 08-09-2012, 01:32 PM

Deff check you plug ins I've swapped my 420a plugs by accident and went to start and nothing also check Ecu

BoostedPhoenix · 08-09-2012, 04:29 PM

Although you flipped the cam sensor 180 degrees, it is still firing igniting in the same sequence, the only thing that would change is that the injectors are now firing in the wrong order, though it should still run like this. It sounds too me more like a bad connection in the wiring harness at that cam sensor, now you flipped it and are pulling those wires tight to plug it in. Pull back the wires in the harness, that is a hot spot to have things melted right by the EGR tube.