Cranking problems

[Jeremywffrd]

Hey guys I wanted to see if yall could help me out. My ECU is not coming online. The car has been sitting for about 8 months and is now ready to crank with the exception of this problem. I took the ecu out looks fine. I dont know alot obout eclipses and I can not locate the mpi relay to check it. My car is a 1997 Eclipse GST. I am not getting spark, I smell gas but I have not checked to see if the injectors are pulsing. The crank sensor is brand new as is the cam angle, plugs and wires are new also. Any help would be greatly appreciated.

Thanks
Jeremy

[Schroeder]

Can you get a Wiring Diagram for your car? Check to see if your getting voltage on the power pin to the ECU. If the ECU isnt powering up more than likely your injectors will not pulse and you wont get spark.

[k3tsurui]

it's an eclipse...it's not suppose to get spark...lol just saying

it seems like you did alot of stuff. if you are not getting power to the ecu, then check for shorts or physical damage to any wiring (especially in all the places that you worked in), if nothing is visible then CAREFULLY power the ecu up manually just to see if it's not the ecu itself that is defective/damaged (if you do not know how to do this, then do not attempt it), then i would undo everything that you've done since it last started up (ie put the old plugs, wires, dizzy cap back etc) your problem is very broad, so the best approach is to do it step by step

[Jeremywffrd]

Yea your right. I am not getting spark either. Here is the thing I thought I found the MPI relay. I took it out and called Mitsu to get another one. The service guy told me it was a all metal relay, the one I found it two relays on a metal bracket. But it was located where I was told the MPI relay should be. It was on the passenger side side kick panel. That was where I was told the MPI should be. Any suggestions?

[Jeremywffrd]

You guys I really need some help. I have located the MPI relay but it does not look like what I have researched. I have posted pics of what I took off my car ( I found this on the passenger side, side kick panel.) It was held on with 2 10mm bolts and had two sets of wires each plug has four wires going into it. On each relay there is four prongs. The two prongs on the left say "COIL" the two on the right side of the relay says...One says "NO" and the other says "COM" bot relays say the same thing. I am at a loss. Mitsubishi told me what I found was not the MPI relay they told me this relay was found somewhere on the fire wall. Help me out you guys.

1997 Mitsubishi Eclipse GST all stock.


**The first pic is what it is suppose to look like from my research and understanding. Please let me know if I am wrong.

[Schroeder]

You guys I really need some help. I have located the MPI relay but it does not look like what I have researched. I have posted pics of what I took off my car ( I found this on the passenger side, side kick panel.) It was held on with 2 10mm bolts and had two sets of wires each plug has four wires going into it. On each relay there is four prongs. The two prongs on the left say "COIL" the two on the right side of the relay says...One says "NO" and the other says "COM" bot relays say the same thing. I am at a loss. Mitsubishi told me what I found was not the MPI relay they told me this relay was found somewhere on the fire wall. Help me out you guys.

1997 Mitsubishi Eclipse GST all stock.


**The first pic is what it is suppose to look like from my research and understanding. Please let me know if I am wrong.



Plug the relays back in and Put your hand on those relays and see if you can feel them actuate when you turn the key to On. Or see if you have 12V power between the X1 - X2 or "Coil" wires on them both when you turn the key to on, of course check for power with the relays removed. If not proceed with the following steps.





Do not do this if you don't feel comfortable!!!

I'm thinking the two terminals marked "Coil" are the X1 - X2 terminals which actuate the relay. Look and see if the two wires going to the "Coil" terminals on the plug side are smaller than the "No" and "Com" terminal wires. More than likely they are. If they are that means your "No" and "Com" terminals are the main power wire that the relay closes. Therefore to "bypass" or Jumper the relays you would just insert a paperclip or piece of wire in the the "No" terminal and jumper it to the "Com" terminal. This bypasses the relays. Do not allow the jumper to touch metal or "Ground" out or you can fry something or blow a fuse. And remember, don't let the smoke out of anything or it won't work anymore!

Good Luck!:goodjob:

[k3tsurui]

i am not a mitsu guy, but that does look like an mpi relay to me. And if it works how i think it does then one of the two coil wires should trace to a 80 or 100 amp fuse somewhere and connect to the alternator somehow. But I am only guessing....check the 100 amp fuse with a multimeter. these fuses are not the glass looking ones where you can see a connection. you have to set your dmm to the diode function as if checking for a short or bridge

[CaTcH22]

Look in your fuse box and see if there is an ASD relay. Auto Shutdown relay. Make sure is clicking. With the key on, check for power at pin 30 and 85. Then check for ground at 86. You can jump power to 87, with a fused wire, not a paper clip. It should send power to the ignition coil and injectors. Try to start it then.

[Jeremywffrd]

Okay so I went out and bought a volt meter. I checked the all four prongs on each relay on the MPI bracket. The 2 "coil" prongs read 0, the "COM" prong read 0, and the "NO" prong read 1.5volts. Now I have a ECU Pinout for a 2G eclipse turbo and it says that pin 12 and 25 are power supplies. Both of these read 1.5 Volts, as did the injector wires on the ecu. The battery itself reads almost 13 volts.

[Schroeder]

Okay so I went out and bought a volt meter. I checked the all four prongs on each relay on the MPI bracket. The 2 "coil" prongs read 0, the "COM" prong read 0, and the "NO" prong read 1.5volts.


Is that with the key in the on position? Even so I would believe you should get 12 vdc on one of the pins on each plug of each relay.

[Jeremywffrd]

yep thats with the key in the "on" position

[Jeremywffrd]

so with me only getting 1.5 do you think the relay is bad?

[CaTcH22]

If you dont have 12v at the injectors and 12v at the coil you need to see if the ASD is being ground by the ECU. The only thing im not sure of is the year. I know 98 has ASD, not 100% on the 97.
Edit: 97 uses two different relays instead of ASD.

[Jeremywffrd]

I just started looking things up about the asd but I cannot find where it is located on a 97 GST. Do you know where?

[CaTcH22]

Hey guys I wanted to see if yall could help me out. My ECU is not coming online.
How do you know your ECU is "not coming online"??

[Jeremywffrd]

Well there is only 1.5 volts running to it and when you turn the ignition to the "on" position the CEL does not come one at all. It used to come before. I blew my engine replaced it and now all this. Everything used to work before. I am not all that smart when it comes to these cars as I do not have a lot of knowledge about them but I thought the power supply for the ECU was suppose to be 12 volts.

Not to mention I was talking to Mike over at 4G and he was telling me that the ECU sounded like it wasnt coming on at all. He told me about the MPI relay to check it. I thought I would check the volts on everything

[CaTcH22]

Yeah 97 is different than 98. Those two relays work together. One is the fuel pump, one is the MPI. If the ECU isnt coming on, check the fuses that power it up.

[Schroeder]

Go back through everything and make sure everything is hooked up in the eng bay and you have good grounds.

[CaTcH22]

Check Fusible link #4, it goes to the MPI system.

[Jeremywffrd]

I have checked all the fuses and replaced them even though they didn t need it. I will go back tomorrow and re check all the grounds on the car.

[Jeremywffrd]

So I went back out and checked all the grounds ( The only ones I could find are the two under the hood. The one going from the battery to the bell housing and the one going from the fire wall onto the intake manifold.) Everything looks good. There is no paint or anything on these surfaces.

I also took my volt meter and out it on 6volts ( last night I had it on 12 Volts) With it being on 6 it read a littler higher than 6 volts on the power supply wire to the ecu but still nothing on one of the relays. The other relay read 10 volts on one of the "coil" prongs.