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Turns over, wont stay alive, help!

stealthtt24

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May 24, 2005
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Orlando, FL
this post was taken from 4g61t.org while trying to fix my tach problem, this came up:

OK so now I have a bigger problem. Im going to go over the steps to see if you guys can help me solve this issue (should make another thread but this might be tied into the wiring)

Before the wiring, we started the car and checked base timing to make sure it was at 5 degrees. It was, and we assume the car was low on gas and ran out cause when I shut it off and tried turning it on later, it wouldnt turn over, I said oh well and got some gas and threw it in there, not trying to turn it on before we fucked with the wiring.

So fast-foward a few days when me and my friend tried to wire up the wideband to log on DSMLINK. We cut the wire coming out of pin 8 on the ecu, IAT, and ran a new wire to the wideband. Still we never tried to start it. Then today we started tackling the tach problem.

The white wire running from the tach filler to the PTR plug, we cut it and wired it so it ran from the tach filler to the dash plug. We found the white wire in the picture shown on the last page of this thread, and just vampire clipped it in there. So it was a "Y", the wire came out of the plug and one end going god-knows-where and the other split off going to the tach filler.

We then tried to start the car and it cranked but would not turn over, once in a while it would turn over and die. But then I noticed that big bronze box near the ecu (i think its the MPI fuse) was clicking like CRAZY. We undid the wiring and returned it all back to stock (wideband pin 8 wiring and tach filler wiring) and now it will turn over and start, but dies immediately!

It has good fuel pressure, and sprays good fuel out of the fuel rail when the fuel pressure regulator is disconnected! So dont think its the fuel pump! What could be wrong?

picture time!

this is the fuse that im talking about that wouldnt stop clicking, it has since stopped since the wiring is back to normal

DigiCampics1149.jpg


the green/orange wire is the stock wire for the intake air temp, pin 8. you can see where we had the red wire that goes to the wideband and how we put it back to stock as well

DigiCampics1148.jpg


that white wire that is butt connected is the dash plug wire, the one that lilevo says to splice in there, you can see the red wire was vampire connected before but now is back to stock!

DigiCampics1147.jpg


this white wire is the wire that leads to the tach filler, we had it cut and go straight from the tach filler to the white dash plug wire
 

BoostedAWD91

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Mar 1, 2007
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Danville,Pa
yeah thats the fuel pump relay, i would make sure there is power going to it or test the relay, i dont remember the specs for it though.
 

stealthtt24

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May 24, 2005
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Orlando, FL
wait are you saying that big bronze box is the fuel pump relay or your saying my problem is the fuel pump relay?
 
Last edited:

That bronze box is the fuelpump/MFI relay. When you hit the "START" position of the key, the ECU will use one half of the relay to activate the fuelpump. But, after you leave off the "START" position, the ECU needs to see CAS pulses coming in, or it will turn the relay off. I'm used to seeing this when there are ECU issues, especially with the "chattering" of the relay that you mentioned.
 

stealthtt24

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so i need to check this thing out and see if it works, how do i go about doing that? test light/multi meter?
 

Dialcaliper

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Jun 22, 2007
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Sounds like another ECU biting the dust.

Pull the ECU out from the passenger side and pop it open - check for funny smells, burn marks, toxic ooze, etc near the capacitors and elsewhere. "Chattering" relays and engine problems are pretty common with capacitor problems it seems.

A couple good references:
https://www.galantvr4.org/ubbthreads/showflat.php?Board=newbie&Number=34701&page=0&fpart=1
http://www.3si.org/wiki/index.php/How_to_Replace_the_Capacitors_in_a_1G_ECU%3F

My personal experience with pictures:
https://www.galantvr4.org/ubbthreads/showflat.php?Cat=&Board=UBB2&Number=497923

Even if the capacitors were already replaced, you should go back and look for any damaged traces on the board, or burn marks on any of the IC's


Quote:
That bronze box is the fuelpump/MFI relay. When you hit the "START" position of the key, the ECU will use one half of the relay to activate the fuelpump. But, after you leave off the "START" position, the ECU needs to see CAS pulses coming in, or it will turn the relay off. I'm used to seeing this when there are ECU issues, especially with the "chattering" of the relay that you mentioned.

 
Last edited:

stealthtt24

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Orlando, FL
we checked the mpi fuse/fuel pump relay and it works! so now onto the injectors and ecu
 

stealthtt24

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May 24, 2005
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Orlando, FL
the injectors arent pulsing or whatnot, my friend tested them with a test light, so basically my ecu crapped?

pics of my ecu i took 30 minutes ago

DigiCampics1153.jpg

DigiCampics1150.jpg

DigiCampics1151.jpg

DigiCampics1152.jpg
 

Actually, those pictures show a rather clean ECU, except for the fact that whoever replaced the caps didn't clean up the flux, but that shouldn't cause the issue you're having. What I don't like is the crappy EPROM socketing job I see. It looks like they used the wrong solder or tools to do it. That can also cause the "chattering relay" syndrome. I think you should send the ECU to someone experienced with repairing DSM ECU's and have it resocketed.
FYI: when you are looking for acid damage, you don't look at the bottom of the ECU. You want to focus in on that area where the caps are, in between the 2 vertical boards. From the one picture you posted it looks very clean, like someone replaced the caps before there was any leakage. But, you need to take a closeup of the righthand vertical board's pins, IC110. A lot of times acid will attack pin #1, and the trace from pin #1 to pin #110 on the rear of the ECU, which kills the MPI relay.
 

stealthtt24

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May 24, 2005
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Can I send it to you Jeff? I know you do awesome work, and you are close to me so it wouldnt take long to get their. I will take close-up pics in a few, thanks I really appreciate the advice.
 

stealthtt24

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May 24, 2005
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Orlando, FL
went out to try and log throtpos and the fuel pump relay was going crazy and would not stop clicking. and i couldnt log either, i have no idea whats going on, im getting a good ecu tomorrow to see
 

The fact that you can't log it confirms my socketing suspicion. The CPU is going nuts because of bad code.
Unfortunately, I fly out tomorrow morning and won't really be back home until 9/13. I'd recommend sending it to Steve P, Terry, or Dave Mertz for resocketing. The ECU otherwise looks very cherry. /ubbthreads/images//graemlins/cool.gif
 

Dialcaliper

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Jun 22, 2007
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Mountain View, CA
It looks like when it was socketed that whoever did it didn't clean back the conformal coating enough - when we did mine, I remember having a hard time getting a solid solder joint when the coating got in the way. Might be part of the problem?
 

I had the same problem and mine is intermittent however it has been solved for about 6 months by just grounding the ECU very well. I replaced the fp relay and that didnt help.
 

stealthtt24

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May 24, 2005
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Orlando, FL
well i put in a local dsm'ers good ecu, and the car fired up! so should i send off my ecu to get resocketed and capped or is my ecu done for???
 

14u2nV

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Jul 22, 2004
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Agency/St. Joe, MO
Ummmm, you did have a chip in that ecu when you were using it didn't you??? I don't see one in the pic.
 

Quote:
well i put in a local dsm'ers good ecu, and the car fired up! so should i send off my ecu to get resocketed and capped or is my ecu done for???



The ECU already has new caps, and looks MINT, so it is DEFINITELY worth saving! Just get it resocketed, PROPERLY. /ubbthreads/images//graemlins/wink.gif
 
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