The best place to start when diagnosing a no start is checking for spark, then fuel. No spark on some cylinders = coil pack, No spark on all cylinders most likely CAS, but it could be other things like the MPI relay, or MPI fuse if you also dont have fuel(injectors not firing). Since you have fuel pressure I would say it is safe to say your pump in most likely good.
The Top Mitsubishi Galant VR-4 Resource
Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.
- Software Upgraded - Reset Your Password to Login
In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.
I was mistaken about the fuel pump turning on, its not.
What could be causing it not to turn on? Or is it just dead?
What could be causing it not to turn on? Or is it just dead?
About the mpi relay. It looks fine, not broken like a fuse would be. Can these be tested? My multi meter shows no resistance...
mitsuturbo
Well-known member
Are you sure you found the MPI relay? I'm not sure why you're comparing it to a "fuse" since it's a metal box with like 8 contacts and corresponding plug.
There's also some relay near the factory battery location. I'm not sure what it's for, but it had been moved a bit on one of my cars. I once had that get wet after a heavy rain and the car would not start.
Also, Try this.. turn the key all the way on. Mark where the CAS is set. Remove it. Spin it with your finger, and listen for injectors firing, and fuel running. Also, while doing this, unplug the plugwires from the coilpack, and watch for spark there. This will tell you of the CAS is working. Also, if you have a known good spare CAS, just plug it in instead, and spin it. If you're not hearing injectors, fuel, or both.. it might be the CAS, or it might be the CAS is not getting proper power/signal, at which time you'd want to get out the volt meter and verify that. If you hear fuel, but no injectors firing, check your connection at the resistor pack.
Double check all connections at the ECU as well. Triple check ALL fuses, both under the hood, and under the dash.
One more thing.. is the CEL coming on when you have the key all the way on?
There's also some relay near the factory battery location. I'm not sure what it's for, but it had been moved a bit on one of my cars. I once had that get wet after a heavy rain and the car would not start.
Also, Try this.. turn the key all the way on. Mark where the CAS is set. Remove it. Spin it with your finger, and listen for injectors firing, and fuel running. Also, while doing this, unplug the plugwires from the coilpack, and watch for spark there. This will tell you of the CAS is working. Also, if you have a known good spare CAS, just plug it in instead, and spin it. If you're not hearing injectors, fuel, or both.. it might be the CAS, or it might be the CAS is not getting proper power/signal, at which time you'd want to get out the volt meter and verify that. If you hear fuel, but no injectors firing, check your connection at the resistor pack.
Double check all connections at the ECU as well. Triple check ALL fuses, both under the hood, and under the dash.
One more thing.. is the CEL coming on when you have the key all the way on?
Last edited:
