jepherz
Staff member
If that's the case, I'd think you could unplug the booster house and plug up the port on the intake manifold, at least to get the car running right.
The Top Mitsubishi Galant VR-4 Resource
Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey. Login to browse without most ads.
My car won't idle :-(
- Thread starter chucklesas
- Start date
chucklesas
Well-known member
So that check valve is in the hose? I replaced the brake lines and system with one out of a donor car. I figured the check valve would have been built into the booster itself, sounds like I assumed wrong though. I'll plug this guy up and try to idle whe I get some time. Thanks for more tips guys.
jepherz
Staff member
Yes, as I recall, in the hose and easy to spot.
jepherz
Staff member
Was this the problem?
chucklesas
Well-known member
I didn't get around to checking it out. I'll stop by Autozone on the way home from work today and pick up a universal check valve and see if that at least fixes the idle issue. I tried to get the car to warm up to operating temp so I could get the low fuel trim to move around and tell me if I have a good deadtime set for my injectors, but then I noticed a strange squeeking sound from the belt area, so I'm going to have to pull my timing cover to see if I can pinpoint it. I've also developed a misfire on the number one cylinder. I noticed it when I started playing with deadtimes with the 880cc injectors. I could hear it on the 1000cc injectors for a little bit, but it would eventually go away. I'm starting to wonder if the head I put on is any good or if it's an issue with the injectors or spark plugs are getting fouled up again. So, a compression check might be in order as well.
I'm so close now, but I'm starting to lose interest in this car again.
I'm so close now, but I'm starting to lose interest in this car again.
Keep the faith.
chucklesas
Well-known member
I think I figured out part of the problem. The recirc tube that came with my ETS kit keeps ripping :-| I was checking to see if maybe I needed to set the GReddy BOV harder or something (like it was opening at idle) and saw that line was ripped. So I cut off the bad part and clamped it back down. Drove the car to the DMV for my VIN inspection and back (like 2 blocks away). It still seems to want to die when the revs drop too fast. I still have to gas it to get the car to even start. The tube ripped itself in half again though, so I'm not sure if that's why I have to give it gas or there are still some other issues that I need to work out.
Still missing on the #1 cylinder (disabling injector 1 doesn't change how it runs).
Weird squeek went away.
I bought a 1-way check valve from autozone for my brake booster. It only has 1/8" nipples on it and I'm running 5/16" or 3/8" line, so for now it's just attached with some nipple adapters. I'm going to have to order the correct part from Mitsu or JNZ.
Edit: I feel pretty dumb for not finding that sooner, but in my defense the rip occured right under my intake manifold right at the BOV. I checked out my log and I'm still high (122%) on my low fuel trim. So I guess I need to reduce deadtime? (currently set to 288)
Still missing on the #1 cylinder (disabling injector 1 doesn't change how it runs).
Weird squeek went away.
I bought a 1-way check valve from autozone for my brake booster. It only has 1/8" nipples on it and I'm running 5/16" or 3/8" line, so for now it's just attached with some nipple adapters. I'm going to have to order the correct part from Mitsu or JNZ.
Edit: I feel pretty dumb for not finding that sooner, but in my defense the rip occured right under my intake manifold right at the BOV. I checked out my log and I'm still high (122%) on my low fuel trim. So I guess I need to reduce deadtime? (currently set to 288)
Last edited by a moderator:
jepherz
Staff member
If your low fuel trim is > 100%, it means the ECU is adding fuel ASAIK. that would tell me you'd want to RAISE deadtime to result in a longer period the injectors are open. /ubbthreads/images/graemlins/dunno.gif
chucklesas
Well-known member
Hokay, so I flipped my UICP around and rerouted my recirc tube, so hopefully I won't run into problems of splitting the tube anymore.
Since the trims were within the ECU limits of being able to compensate I didn't bother to change them. Instead, I actually swapped out the 880s and tried putting the 1000cc injectors back in. For some reason I would lose the number one cylinder on the 880s. So I put the 1000cc in, this time I set my deadtime for 360uS. I guess the 450 value was wrong for these injectors. Low fuel trim is at 81%, so I could probably pull back a little more deadtime (1 or 2 hex), but it's within the limits of the ECU, so I'm happy with that for now. Although now I understand what octane reset does (at least I think I do). Each time I shut the car off and turn back on the fuel trims reset to 100%, so I either need to remove the octane reset or dial in the trims a little better.
The idle is better, but still temperamental. Most times I start it will want to die out: idles at 800rpm, and then slowly drops until it shuts off. Other times I'll start it and it will start to idle at 937rpm and then I get idle surge to about 1531rpm. The idle surge kind of leads me to believe I have an issue with a vacuum leak, but the fact that it's not consistent has me scratching my head. During the surging the ISC shows 0 counts on the logger, and I can turn the BISS all the way in, and still be surging from 1000 to 1500 rpm. If I adjust the CAS to be less than 5 deg BTDC the surging will go away.
Looking at the logs nothing really jumps out at me. ISC is 0 (for the most part) at idle, airflow seems to coincide with rpm, throttle position reads 9.02% closed up to 100% fully open. Noticed the injector pulsewidth goes to 0 at around 1500rpm and comes back on when it drops to about 1200rpm when surging.
I guess the next step for me is to replace the BISS and check for any other intake leaks. I guess I should get my downpipe fitted for a wideband O2 sensor as well. Is there anything else I should be looking for? BTW, I believe my throttlebody is from a 90 NT DSM, if that makes any difference to you guys. Coolant lines are hooked up.
Edit: I failed to mention, that when it won't even idle at 800rpm if I blip the throttle and let the rpms fall it will shut off. If it's surging and I blip the throttle it will actually catch before rpms fall too low and stay running. Also, the exhaust fumes make my eyes sting. /ubbthreads/images/graemlins/bawling.gif
Since the trims were within the ECU limits of being able to compensate I didn't bother to change them. Instead, I actually swapped out the 880s and tried putting the 1000cc injectors back in. For some reason I would lose the number one cylinder on the 880s. So I put the 1000cc in, this time I set my deadtime for 360uS. I guess the 450 value was wrong for these injectors. Low fuel trim is at 81%, so I could probably pull back a little more deadtime (1 or 2 hex), but it's within the limits of the ECU, so I'm happy with that for now. Although now I understand what octane reset does (at least I think I do). Each time I shut the car off and turn back on the fuel trims reset to 100%, so I either need to remove the octane reset or dial in the trims a little better.
The idle is better, but still temperamental. Most times I start it will want to die out: idles at 800rpm, and then slowly drops until it shuts off. Other times I'll start it and it will start to idle at 937rpm and then I get idle surge to about 1531rpm. The idle surge kind of leads me to believe I have an issue with a vacuum leak, but the fact that it's not consistent has me scratching my head. During the surging the ISC shows 0 counts on the logger, and I can turn the BISS all the way in, and still be surging from 1000 to 1500 rpm. If I adjust the CAS to be less than 5 deg BTDC the surging will go away.
Looking at the logs nothing really jumps out at me. ISC is 0 (for the most part) at idle, airflow seems to coincide with rpm, throttle position reads 9.02% closed up to 100% fully open. Noticed the injector pulsewidth goes to 0 at around 1500rpm and comes back on when it drops to about 1200rpm when surging.
I guess the next step for me is to replace the BISS and check for any other intake leaks. I guess I should get my downpipe fitted for a wideband O2 sensor as well. Is there anything else I should be looking for? BTW, I believe my throttlebody is from a 90 NT DSM, if that makes any difference to you guys. Coolant lines are hooked up.
Edit: I failed to mention, that when it won't even idle at 800rpm if I blip the throttle and let the rpms fall it will shut off. If it's surging and I blip the throttle it will actually catch before rpms fall too low and stay running. Also, the exhaust fumes make my eyes sting. /ubbthreads/images/graemlins/bawling.gif
Last edited by a moderator:
chucklesas
Well-known member
I guess I should check the coils on my ISC /ubbthreads/images/graemlins/uhh.gif I'll do that first when I get home.
Octane reset does not make your fueltrims reset. If the ECU is losing its memory everytime you shut down, that could also be adding to your idle issues, as the ECU learns the ISC settings also. Does your clock also reset? Is your dome light working?
chucklesas
Well-known member
Clock light and dome light are good to go. I just went out and idled the car for 15 minutes. The coolant never went above 175, so I couldn't get the trims to move around, but they were all reset to 100% again. So I guess I need to check that there's a constant +12 to one of the pins on the ECU? Which pin would I be looking for?
chucklesas
Well-known member
I have +12 on pin 103
AND ISC ohmed out good between 1-2, 2-3, 4-5, 5-6
AND ISC ohmed out good between 1-2, 2-3, 4-5, 5-6
Last edited by a moderator:
chucklesas
Well-known member
I don't know if these will help with the diagnosis, but here's the failed startup attempt without using the gas pedal:
Galant VR4 start fail
And the idle surging while screwing the BISS all the way in:
Galant VR4 idle surge
Galant VR4 start failAnd the idle surging while screwing the BISS all the way in:
Galant VR4 idle surgeIf you have good battery voltage on pin #103, then either:
1. you have a problem inside the ECU with that 12 volts keeping the RAM alive. There's a surfacemount tantulum cap right next to the CPU that stores the voltage, so you can check rather easily for +12 volts on it with the car shut down. Or,
2. You have something screwed up with your octane reset code, and it is resetting all of the RAM, not just the upper memory addresses. The fueltrims are addresses $0040 thru $0043. D0B4 is usually set to jump to D0E2 (command is 2B 2C) upon cold reboot, but we change it to 2B 28 to make it jump to D0DE instead, and also reset the octane value. I could see where if you would do a 2B 21 instead it would move you back 7 bytes, and cause it to always reset the fueltrims when you start the car. I'm really reaching here. /ubbthreads/images/graemlins/wink.gif
1. you have a problem inside the ECU with that 12 volts keeping the RAM alive. There's a surfacemount tantulum cap right next to the CPU that stores the voltage, so you can check rather easily for +12 volts on it with the car shut down. Or,
2. You have something screwed up with your octane reset code, and it is resetting all of the RAM, not just the upper memory addresses. The fueltrims are addresses $0040 thru $0043. D0B4 is usually set to jump to D0E2 (command is 2B 2C) upon cold reboot, but we change it to 2B 28 to make it jump to D0DE instead, and also reset the octane value. I could see where if you would do a 2B 21 instead it would move you back 7 bytes, and cause it to always reset the fueltrims when you start the car. I'm really reaching here. /ubbthreads/images/graemlins/wink.gif
chucklesas
Well-known member
Hmm, interesting. I looked at my code, and apparently I never actually put in the octane code. It's still set for 2C. So, I guess I'll check the ECU tomorrow afternoon and probably pull up another stock 931 bin and ONLY put in the injector and MAF compensation values and leave everything else alone. I thought I had a stock 943 chip, but I can't find it anywhere. Anyway, I'll post again tomorrow with updates. Maybe I'll remember to stop by AceHardware too and see if they have an O-ring for the BISS.
Mabye an obvious post, but what condition is your ecu in? My ecu was the source of all my idling problems (running supper rich to the point of stalling, barely idling, strange warm up issues)
chucklesas
Well-known member
it's been about 8 years since the ECU was rebuilt. I guess I could freshen it u with some new caps. Anyway, I haven't touched the car in about 2 or 3 weeks. I was cleaning up around the house today and decided I should start it since it's been sitting for that long. Took a bit of cranking to get it started, but once it was going I wasn't having any idle issues. I didn't leave it running long enough to see if it would start surging (only idled for about 5 minutes, not enough to warm up to 192*). I don't get it. Must be those darn gremlins at work.
chucklesas
Well-known member
I swapped in a blacktop cas and replaced the fouled plugs today (haven't started the care in a couple months). It seemed to idle and run better. Still not idling at 800rpm or 1000rpm or whatever I set the ECU to (I don't remember). More like 600rpm. I guess I'll try to ground everything and back the biss out, but just screwing around with the biss earlier biss didn't seem to do much for the idle rpm and the car dies when I try to ground the timing terminal. I'm thinking maybe I need to try a different throttle body with a known good FIAV and ISC. I don't think I was able to get the coolant up to 192* to see if I still have idle surge problems. Maybe I'll try to run it again tomorrow if it's warmer out.
85tr
Well-known member
Ive been battling almost the same issue with my brothers car for like 6 months, i have replaced everything and it still runs like a intercooler pipe is off the car. It will barley idle and if you try to drive the car it will buck and have no power ,then as soon as you let off the gas it dies.Did you ever get this problem totally fixed ?
