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ECMlink ECU visual check [pics]

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turtlebain

10+ Year Contributor
447
27
May 16, 2012
Rochester, New_York
I'm having an issue keeping the car at idle, it wants to die almost immediatley when started up, Car was holding idle fine just about a week ago (and driving) but then lost fuel pressure from bad hose connection inside tank, fixed it, and then had start up issues.

New 6 bolt & Trans build, COP setup, 1G CAS from 90 wired direct into harness (no adapter harness made)

Test's done:
I have done a boost leak down test to about 20 PSI, running wastegate pressure now..
Tested Spark turning over engine by hand with grounded spark plug watching them fire 1 by 1
Tested fuel by taking the rail off tying injectors to rail with metal wire, applying battery voltage. Each is misting fuel about the same volume with good spray pattern.
Resistance at injectors They all fluctuated up when testing
4 - 2.6-2.8 ohm 3 - 2.6-2.8 ohm 2 - 2.6-2.7 ohm 1 - 2.6-2.8 ohm
Compression results all were done until compression tester was rising very slowly
4 - 150 PSI @ 12 cranks
3 - 145 PSI @ 13 cranks
2 - 100 PSI @ 12 cranks
1 - 150 PSI @ 12 cranks
* note on compression this motor is still breaking in and when attempting fuel injector test 1st time cyl 2 filled with gas and wiped oil off walls, before this car was running, compression test ed at 100 100 40 100 before ANY break in whatsoever. When applying oil in cyl 2 compression jumped to 135+ for that cylinder. So I'm seeing improvement there but still lower than others. break in is not complete at this point. Also note on the build my machinist fitted rings to 35+ PSI tolerance by Manley's specifications which I believe calls for them to be a bit looser to allow blow by with high boost. So I don't think this engine is going to achieve "normal" factory motor compression standards. I could be wrong here.
Tested CAS by turning it over and listening for injectors to fire.

Also not timed with a timing light, but the marks do line up on the cam wheels all the way across. I was going to take it somewhere to get that done as I don't have access to a timing light currently.

I'm looking into the possibility that the ECU has gone bad

Top side of ECU looks OK to me with no apparently blown capacitors , burns, you know, usual signs of circuitry malfunctions:
 
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Underside has a white tinge to it in parts, others are orange. Tried to get the best piics to display this.

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Thanks for the reply.

Problem is it starts, then comes down within a few seconds, struggles like it's gasping for air or fuel, then dies. I've experienced this before when there was a MAJOR boost leak. I checked and rechecked everything, even went out and got new t-bolt clamps so they are tight. The ones before looked to be at their limit so not getting as tight as they could.

Noticed a boost leak at about 20 PSI at the manual boost controller, tried tightening another zip tie on it and it seemed to help just slightly.

I was about to log then ECM link decided not to connect, was having some port issue (even though it connected just fine minutes before) then laptop battery died. So I took a break, was starting to get frustrated

What really boggles my mind is that it was running well about a week ago, fuel pressure dropped due to in-tank issue. I solved it, but now having other issued that seem to be unrelated! I had the fuel pup out, is it possible for the fuel to go bad in about a day being open to the environment?

MAF was reading 40 AirflowPerRev - Tried adjusting MAF comp, it didnt seem to make any difference at all but maybe this is due to connection issues.
O2 sensor was NOT cycling, but at which point is it supposed to cycle, a few days ago it was cycling, but at a slower frequency than I saw on ECMlink demo videos.
Timing jumping all over .. is that normal!? I tried pulling a 1G CAS from junkyard yesterday but couldn't find one.
I would is it possible to do a full reset on settings and does it sound like I should?
 
is this the car in your build? the 98 gsx? your build specs say its SD, but i see a 2g maf in the pics. which one are you on ?

also, attaching a log from cold start to rad fan on would be good to see, then we can help more.
 
I have everything for SD but haven't converted yet. 2G MAF.
 
I'll try log again and post back in a few min.
 
Here's the log.

I needed to keep blipping the throttle in order to keep it from shutting off.
 

Attachments

  • log.2015.05.30-01.elg
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You'll need to get out the timing light and sync the CAS with the mechanical timing ASAP.
The relationship between throttle and RPM seems very laggy.
Can you include the ISC/IAC steps in the log?
I assume the didn't use the 2G TPS. What TB are you using?
 
You'll need to get out the timing light and sync the CAS with the mechanical timing ASAP.
The relationship between throttle and RPM seems very laggy.
Can you include the ISC/IAC steps in the log?
I assume the didn't use the 2G TPS. What TB are you using?

OK Steve. I'll see if I can get my hands on a timing light and sync to 5 deg. I've never done this before so I'll have to read up on how to do it. It's also a 1G TPS / 1G throttle body and intake manifold. BISS screw temporarily set 2 full turns out until I can get idle under control and adjust with link. I sure can do a log with those things.

Thanks so much.
 
OK CAS was sync'd to 5 deg. BTDC and I added the ISCPosition to the log. Here it is. I was applying gas to keep it up for a bit, then let it die at the end.
 

Attachments

  • log.2015.05.31-01.elg
    35.6 KB · Views: 145
Are you sure your O2 sensors are working?
The ECU seems to be configured for a narrowband in the front which is reading low and a wideband in the rear which is largely pinned high.

The ECU thinks it's adjusting the ISC but I don't see much reaction to the changes.
 
Update: After revving up the engine for a little while to about 2.5-3k RPM I was able to get the idle to stick around 1,100 RPM, less and it wanted to die. I'm wondering if the idle is being affected by low voltage. I'm seeing a big drop when I turn on lights, wiper motor, etc.

CombinedFT, Timing, & RPM seem to be very jumpy.

It's a stock O2 sensor in front, AEM Uego Wideband in rear. I was starting to see Front O2 Cycle when I adjusted deadtime to try bringing down CombinedFT - I'm not sure and was considering replacing O2 sensor in front. The rear was pretty close to the readout on the gauge display it seems to be working properly.
MAF seems to be reading OK although I don't know what AirflowPerRev I should see at 1,100 RPM

I'm getting the car aligned right now, so I wouldn't be able to do another log until later tonight.
 
Hey guys, guess what? The timing light I bought has a "timing advance" dial on the back that they somehow thought would be good to make really really ridiculously easy to move.. So today I was going to put it back away , but noticed it was on 20 deg. advance. I knew I had set it to 0 to start when dialing it in before but just for kicks I gave it a check. Sure enough. It was right about 20 advanced. Dialed it back to 5 this time taping the dial so it couldn't move. and doesn't die anymore!! Thanks everyone for the help. Steve, very very helpful!!

Still is having some idle issues. Following link demos, I tried setting idle to 900 RPM. It will get there for a few seconds then jump back up, sometimes all the way to 1200. I reset MAF settings after tried dialing AirflowPerRev to 25 around 900 RPM. Then tried dialing in injector dead time to get rid of CombinedFT adjusted all the way to 680! Concerned it's too high. I was seeing O2 cycle and then it would stop.

Also noticed some loose connections at ECU. I have not touched these yet but I think it may be a source for problems so going to solder them and get back to you guys with results.

I think I'm on the right track. Oil leak on back side of the motor is concerning too. Trying to deal with both of those things and get it inspected tomorrow.
 
I would go grab another idle log right now but I already pissed off the neighbors today :dsm::argue:
 
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