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420A Help 2g eclipse no spark

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Daniel b

Proven Member
71
6
Sep 15, 2021
Middletown, Rhode_Island
So I bought a 1999 Mitsubishi Eclipse gs 420a engine, it cranks but won’t start and has no spark, I have changed crank sensor and coil pack. Any ideas?
 
the scanner wasnt working I’m going to try a older one today and I’ll let you know maybe the ecu went bad.
 
If check engine light won't come on or scan tool won't communicate with the ECM, might just be bad "engine fuse/relay"
 
If the check engine light doesn't "bulb check" when you turn the key to the on position. You have a problem with your "reference voltage" circuit.
This isn't nearly as bad as you think it will be as you read this. I've done it at least 4 times and is the first thing I do when I buy a 2.0 Neon. It takes about 4 hours the first time. Now I can re-wrap every wire and re-instal it in about 2 hours.
From my experience with this engine from the Neon world... If the harnesses are in any way similar, my guess is they're VERY closely related I would take the engine harness off, un-loom it, look for, separate and wrap the the burnt wires with electrical tape, follow them to the sensor they go to CKP, CMP, o2, coolant temp sensor ect. Check the electrical connectors for melted, loose, corroded or otherwise abnormal conditions and replace the connectors as needed. My advice is to solder the "reference voltage" wires and use very secure connections on the ground and 12v wires.

I did forget to say "Check the fuses". There is a fuse before the ECU that blows if there is a short in the reference circuit.
In the 6, 1g Neons I've owned. One had a bad computer. It's not a common issue, but a very commonly misdiagnosed issue. The most I paid for them was $800. That was for an Expresso coupe. I paid $200 for the one with the bad ECU. If these ECUs are bad, most of the time, the alternator won't work but the check engine light will come on.
Even if it is an ECU, go to the junk yard yard and pick one up. $50 at most, they aren't VIN specific and one from an automatic SOHC will work in a 5 speed DOHC. Just make sure the ECU plugs are correct.
 
Okay yeah I know check engine light is on from the aftermarket exhaust and wiring is a bit hacked but almost everything works except running.
 
You would still have spark if the timing was off. It would just be sparking at the wrong time. Have you pulled each plug to see if they're all sparking? All you need to do is touch it against one of the bolts as a ground while somebody turn the engine over and look for the spark.
 
Okay yeah I know check engine light is on from the aftermarket exhaust and wiring is a bit hacked but almost everything works except running.
What am I missing here? If the check engine light is on AND the scan tool isn't communicating, you have a one of a kind problem that shouldn't exist outside of extremely rare instances.
Did you check your fuses, specifically number 13?
 
You can do key dance, 10times on and 10times off and it will MIorse codes for you, my RS had weird problem when I could communicate with the scan tool, I took dashboard off and while it was off I took off the cobra alarm system, I didn't find anything wrong with the wiring and put it back together and my srs light came on cuz I forgot to connect the srs connector, I hook up MUT III tester and suddenly obd port worked just fine and I was able to read codes with any scan tool I had
 
What am I missing here? If the check engine light is on AND the scan tool isn't communicating, you have a one of a kind problem that shouldn't exist outside of extremely rare instances.
Did you check your fuses, specifically number 13?
He could just have a lose connection at the OBD port. It's actually not rare at all, I had the same issue. My scanner wasn't communicating but the light was on, all I had to do was wiggle the connector a bit and hold it at the right angle and then the scanner started communicating.
 
Agreed. That is one of the very rare circumstances I'm speaking of. I've been in the auto repair industry for some 15+ish years in an emissions zone. I've seen that particular issue at most, 3 times.
I'm really just trying to see if the OP is going to fix the car. They seem defeated at this point and fishing for a part to launch at the car, instead of taking the time to diagnose and fix the electrical issue they're having.... properly.
 
What am I missing here? If the check engine light is on AND the scan tool isn't communicating, you have a one of a kind problem that shouldn't exist outside of extremely rare instances.
Did you check your fuses, specifically number 13?
No sorry check engine light just no spark I’ll send a video.https://www.youtube.com/watch?v=psguD3lE1ho

No sorry check engine light just no spark I’ll send a video.https://www.youtube.com/watch?v=psguD3lE1ho
and scanner might not be connecting because of how new it is I’m going to have my friend try with his older one

Agreed. That is one of the very rare circumstances I'm speaking of. I've been in the auto repair industry for some 15+ish years in an emissions zone. I've seen that particular issue at most, 3 times.
I'm really just trying to see if the OP is going to fix the car. They seem defeated at this point and fishing for a part to launch at the car, instead of taking the time to diagnose and fix the electrical issue they're having.... properly.
What am I missing here? If the check engine light is on AND the scan tool isn't communicating, you have a one of a kind problem that shouldn't exist outside of extremely rare instances.
Did you check your fuses, specifically number 13?
sorry check engine light isn’t on here is video
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is your coil pack MSD? if it is, try OEM, people had a lot of problems with MSD coil packs
I tried the original it came with as well still no spark
 
I’m going rotate because I heard about people only getting spark when it’s rotated 180degrees
The connector is supposed to be facing downward (towards the ground). If it happens to start working when you flip it, then it needs to be replaced.
 
I’m going rotate because I heard about people only getting spark when it’s rotated 180degrees
yea, connector is supposed to face down, and make sure you have everything plugged in, I know how it is when you're unplugging and testing out stuff, it's easy to forget to plug tyhem back, wouldn't hurt to spray some connector spray in the connectors, or wd40, these are old cars so corrosion on connector pins can also cause electrics to fail
 
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