420A Eclipse GS 420a no spark in 1 and 4

[Dashracer95]

I have a 1998 Eclipse GS with a 420a. So far I've replaced the coil pack, plugs, wires, crank position sensor, cam position sensor, new alternator and new battery. She still has zero spark on cylinders 1 and 4. She also isn't charging the battery. Note: The PCM I currently have is out of a 1997 eagle talon, also with a 420a.

The connectors didn't go on easy. So here's my question, are the pinouts different from 97 to 98 to control the engine? Unfortunately I don't have the original PCM to compare. It was dead, so it got tossed. The engine easily starts and runs on cylinders 2 and 3.

 

[luv2rallye]

ECU pinout: https://www.dsmtuners.com/threads/2gnt-pcm-connector-views.283950/

Also try: https://www.2gnt.com/index.php?d=ECU_Pinout

 

[Dashracer95]

ECU pinout: https://www.dsmtuners.com/threads/2gnt-pcm-connector-views.283950/

Also try: https://www.2gnt.com/index.php?d=ECU_Pinout

So, with the fact that the two connectors on the 98 harness had a difficult time going on the 97 ECU, can I assume that ECU pinout is different or its not calibrated to run the 420a in my 98 eclipse?

 

[luv2rallye]

Sorry I can't answer that as I'm extremely knowledgeable on the Mitsubishi turbo engine but not the Chrysler 420a. You might try searching the 2gnt forum for the correct answer.

One thing I just found on this forum however was a mention of injector 3 and 4 may be swapped on the 97 ECU (https://www.dsmtuners.com/threads/2gnt-owners-look-here-ecu-pinout-diagrams.185600/post-1559509) so you might check into that as well although I don't see how that would effect spark even if it was true. Your best bet is the search the 2gnt forum or hope an 2gnt guy chimes in. Wisemen Doug99RS and Black'98DSM are NT guys - you might try messaging them. Or ask Ludachris (this site's creator) who all the NT guys are that could help.

 

[BLACK'98DSM]

The 1997 Eagle Talon ESI and the 1998 Mitsubishi Eclipse GS were both factory equipped with the same ECU and wiring. Nothing should differ in that aspect of the cars and you should be able to use that ECU with no issues.

However, it's very common for those 2 large connectors to break and corrode. I've seen some that fall off and with chalky oxidation on the pins. I would start with making sure you have clean and tight connections there.

Normally, when cylinders 1 and 4 lose spark, it's a faulty ignition coil. The 420A coil pack, of course, has two separate coils as one assembly. Coil A (cyl 1 & 4) Coil B (cyl 2 & 3). It sounds like an A failure, which I have seen before. I'd argue that an individual coil failure is more common than the entire coil assembly dying at once. You do say that you've replaced the ignition coil assembly. Were you having this same issue prior? And have you tested the new ignition coil?

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[Dashracer95]

The 1997 Eagle Talon ESI and the 1998 Mitsubishi Eclipse GS were both factory equipped with the same ECU and wiring. Nothing should differ in that aspect of the cars and you should be able to use that ECU with no issues.

However, it's very common for those 2 large connectors to break and corrode. I've seen some that fall off and with chalky oxidation on the pins. I would start with making sure you have clean and tight connections there.

Normally, when cylinders 1 and 4 lose spark, it's a faulty ignition coil. The 420A coil pack, of course, has two separate coils as one assembly. Coil A (cyl 1 & 4) Coil B (cyl 2 & 3). It sounds like an A failure, which I have seen before. I'd argue that an individual coil failure is more common than the entire coil assembly dying at once. You do say that you've replaced the ignition coil assembly. Were you having this same issue prior? And have you tested the new ignition coil?

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Three coil packs so far all check out with good numbers. Two used and one new. I'm still leaning towards the fact that I probably have the wrong ECU. Nobody has confirmed that the pinouts on a 97 are different than a 98 or if they are potentially calibrated differently from the two years.