ECU problem??

97spyder · #1 03-29-2007, 04:16 PM

OK. so i've posted about this problem before but it took me forever to get to the car and test everything, and first off i would like to thank Mikdlb, SL3000qt, and gthompson97 for helping out earlier.

I have a 97 mitsu. eclipse spyder gst conv. 2.0 liter turbo, has a 5 speed manual and eveything is stock. I left the house and the car died abruptly, tried to start in and it turned over fine but no spark, pushed it back to the house, and so far i have checked all fuses, tested the coil packs, thanks to Mikelb I have tested the transistor pack, it all came back good. I also took out the ecu, opened it up checked both side of the board and everything looks ok, no bursted caps or burnt looking spots or anything. So as far as i know that is everything in the system? also the engine light is not on. so i'm basically lost. the mitsu dealer mechanic said after i test the transistor pack i should bring it in, he said there was a couple tests they could run even though the car wouldn't start??? but if it's the last part in the system why wouldn't i just go buy another?

Well anything will help, and i really appreciate any i get.

thanks,
97spyder

l_eclipse_l · #2 03-29-2007, 08:31 PM

So you are getting fuel or no? Can you hear the fuel pump at all when trying to start it? Do the plugs get wet? I'm assuming you have verified the battery is good, correct?

97spyder · #3 03-29-2007, 09:56 PM

Yeah, I can hear the fuel pump turn on. Plus the battery is good. Car was running perfect then just died.

spyderturbo007 · #4 03-30-2007, 08:44 AM

Have you verified that you are getting spark by pulling one of the plugs and checking? Also, did you notice an unusual smell from the ECU? Sometimes ECU problems aren't easily seen.

97spyder · #5 03-30-2007, 12:37 PM

Yes i have pulled the plugs out and checked for spark that way, still nothing. and i didn't notice any smells coming from the ecu. was wondering if one of the 2 relays under the stereo could be the problem? also the check engine light did not come on. was wondering if any sensors such as cam positon or anything like that could stop spark, but if so i would think a check engine light would come one. or do they not turn on if the car doesn't start?

spyderturbo007 · #6 03-30-2007, 03:23 PM

The check engine light should come on for about 5 seconds and then turn off if you turn the key to the "On" position. If the CEL remains on, there is a problem with the ECU if the key is in the "On" position.

Let me look around and see if I can find anything relating to the fact that your CEL doesn't come on at all. Did it used to come on, or is it possible that the bulb is just burned out?

Apparently, if your CEL never illuminates, that means that it's not "waking up". This is most likely your problem. I'm looking into what to check on a 2g, since I can only find information for a 1g.

Here is information (for a 1g) I found on tuners posted by the ECU Guru in the community, Steve!

The first thing you should do if your ECU doesn't power up (CEL on for about 5 seconds, the boost gauge displays 0) is check the two fusable links and the room fuse #19. Measure the fuses for continuity (0 ohms resistance) rather than look at them. Then check for battery voltage at the ECU and MPI relay pins. Remember that the ECU doesn't get power on pins 102 and 107 until the MPI relay is activated by turning the ignition key to RUN or START. If the MPI relay doesn't activate try grounding its pin 8 and check that power shows up on its pins 4 and 5. If that works then either the ECU isn't seeing the IG1 signal or the ECU is damaged.

If power is present on ECU pins 102 and 107, the ECU grounds are good and the ECU doesn't power up it's damaged.

97spyder · #7 03-30-2007, 03:45 PM

I'm sorry when i posted that the light didn't come on i meant and stay on like if something was out of whack, it does come when you first turn the key then turns off after a couple secs.

spyderturbo007 · #8 03-30-2007, 03:50 PM

I learned something new from trying to help with your problem, so no harm done.

Ok, back to the no spark issue. Did you check every single plug or just one of them? It will help to narrow things down if we know if it's a general problem, or just specific to certain plugs.

97spyder · #9 03-30-2007, 06:48 PM

yeah i checked a plug in every plug wire. i was also wondering how many parts could actually interfere with the spark, i only know of the coil packs, the transistor pack and the ecu.

spyderturbo007 · #10 03-31-2007, 10:16 PM

Here is the order I would check things in:

Fuses
Ignition wire connections
CAS (Cam Angle Sensor)
CPS (Crank Postion Sensor)
Power Transistor
ECU
MPI Relay

I suspect that your problem is either the CAS or the Power Transistor. It sounds like the ECU is good and the MPI powers both the injectors and the ECU, so if you have fuel, it's probably not the problem.

You can check your repair manual for the sensor testing procedures.

97spyder · #11 04-04-2007, 11:49 AM

ok, according to the book on the car in order to test the crank position sensor or the one for the cam it says i need a test harness, is there a way to test them without the harness? or is that something i have to look into buying or renting?

Mikelb · #12 04-04-2007, 05:00 PM

Make sure the CAS is correctly hooked up... that was why mine wouldn't start this weekend... it didn't even turn on my fuel pump...

97spyder · #13 04-04-2007, 09:39 PM

well if i want to test either sensor my book says i need a test harness. and i can't get 1 anywhere i know of so i called the mitsu dealer here and he said they do a whole diagnosis on the whole elec. system for 110.50 so i guess im gonna break down and try that. just gotta tow it down there, so thanks to everyone who has helped, i'll post again to let you know anything i find out from this.

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