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My car won't idle :-(

chucklesas

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So I can barely get the car to start and when I do I have to hold the throttle at about 25% to keep it running (very rough running). I tried to play with the CAS to maybe adjust the timing some, that seems to help only slightly (seems I have to have it set just right to get it to start). I backed the BISS out almost all the way... also helps a little. Even after all this the car still won't idle well (I killed the battery twice already trying to restart it over and over).

So, some relavent issues that I think would relate to this poor idle, or lack-there-of:
1. I'm running a COP setup and haven't been able to set base timing (not that I could get the car to idle for long enough to do it anyway)
2. I'm using some PTE 1000cc Injectors. I have my ecu set up to run 940cc injectors; I read on a couple sites that this is the true rating for the PTE 1000cc injectors. I added 450 uS to the deadtime; I'm not sure what this should be set for. I've seen some people say 330-360 (since the 880s run at that), but I've also seen 450 uS called out on some websites. I may try to swap in some 880s and change my ECU settings to see if that helps any.
3. I have NGK BPR8ES spark plugs installed. I decided to yank the COP and swap in a coil-pack I have laying around. Once I got the COP out I went ahead and pulled the spark plugs and they are super-black (fouled). They smell pretty aweful as well. I'm not sure if I'm running super rich, or if this was caused by me going 100% throttle while trying to get the car and keep the car idling. I have an extra set of plugs, but I don't want to put them in if I'm just going to foul them up, too (I was just going to take some sandpaper to the electrodes and try to clean them up a bit. I'm also thinking maybe I should go grab some BPR7ES plugs instead.
4. I'm running a 482 MAF, this sensor was sitting in the car when I had the engine fire, I was thinking it would probably still be okay since it was away from the main heat source, but I may swap in a 1G MAF and change my code back to rule that out, too.

So right now I'm thinking my way forward will be to swap in a new set of injectors (maybe even borrow some 440s from someone), 1G MAF, a stock coil-pack, and standard chip.

Any other thoughts?
 
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chucklesas

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By the way, I'm pretty sure I'm doing it right, but I guess I should verify: for injector compensation I want to use the equation =dec2hex(440/(injector size) * 74) ?
 

iLLeffeKt vr-4

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I'm assuming you're running dsmlink? The global for those injectors should be -51% and deadtime 450 which you have right. When I had a COP setup on my galant I could set the timing just like I did when I had spark plug wires.
I would go with some bpr7es plugs or even the stock bpr6es until you figure this thing out. Is the tps set right? Did you ground the timing when you set the biss screw?
 

prove_it

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Don't use sandpaper to clean your plugs. It will damage them, instead use a torch to heat up the electrodes til they are red hot. That will clean them way way better than sandpaper.
 

chucklesas

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Dayton, OH
Quoting iLLeffeKt vr-4:
I'm assuming you're running dsmlink? The global for those injectors should be -51% and deadtime 450 which you have right. When I had a COP setup on my galant I could set the timing just like I did when I had spark plug wires.
I would go with some bpr7es plugs or even the stock bpr6es until you figure this thing out. Is the tps set right? Did you ground the timing when you set the biss screw?



No DSM Link, I'm just editing the bin file for my EPROM. My timing light won't work with my COP, I tried to use it the one time I was able to get the car to idle. I have a feeling the issue is with these injectors.

Also, I have a '90 N/T throttle body installed. I noticed on the TMO logger that when the throttle is fully closed the closed switch says "off", but shows "on" when the throttle plate is open. This seems reversed to me.

I did not ground timing when I set my BISS since I just adjusted the screw with the engine off. I can't get the car to idle long enough to make any adjustments.
 

Do you have a way to log the MAS Hz, to make sure you are getting a good airflow signal at idle? What base fuel pressure are you running? What fuelpump? AFPR? For stock 37psi base fuel pressure, I use 24h for Global Fuel and 312uS deadtime.
 

chucklesas

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I have the Hz count cut in half, but if I remember correctly I was seeing values around 40-50hz which would put me at 80-100hz (actual), I'll double check the log when I get home.

...255lph Walbro fuel pump with an Aeromotive FPR. I tried to set the base fuel pressure at 37psi, but this was with the engine off and just the fuel pump running (I figured it would get me in the ballpark until I could warm up the engine to adjust it properly). I haven't had a chance to see what the number is while the car is running with the vacuum port out. I may try to adjust the ECU settings before swapping out injectors, since that's easier to do.

I'll let you guys know what happens from here.
 

chucklesas

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So I swapped out my 1000cc injectors with some 880s and made the necessary adjustments to my ECU Bin File (27 hex (840cc) vs. 23 hex (940cc)) and set the deadtime for 312uS. I'm not actually sure what brand this are, I bought them used off a board member on here a couple years ago. They say Python on the top, I remember searching at one point in time for them and came up with nothing.

Anyway, I ran into the same problem with starting it up. I have to gas it to get it going and keep on the throttle to keep it in idle. So I made this video, started it, tried to let it come down to idle, but right before it stalled I gased it again and tried to hold the revs until it smoothed out a bit, then I just went ahead and took it to the 5000rpm stutter.

After this run I plugged in my laptop logger and grounded the timing lead in the engine bay. This actually allowed the car to run on its own for a bit without me having to hold down the throttle. I was able to set the base timing, base fuel pressure to 37psi and screw the BISS in a bit to hold the idle at 1000rpm without trying to surge. However, as soon as I pull the ground off the timing lead the car just dies again. Maybe the extended timing maps are screwing me up?

Here's the video: I'll try to decipher my log info and get that info up shortly.
Galant VR4 start-up attempt with stutter

Edit: Video is not working for some reason, I may have to reload it.
 
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chucklesas

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Feb 14, 2003
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I finally got around to converting my logs.
Here's one where I had to keep the throttle over 10% just to keep the car running:




The Low Fuel Trim is not graphed, but it was at 140%. Mid and High were at 100%.

Also note that my MAF Hz is only being logged at 1/2 the actual value, so 100Hz chart value is actually 200Hz.

So what can you make of this log?
 
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chucklesas

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Dayton, OH
Well, I got off the phone with John (Toybreaker), he suggested a few things. He felt the symptoms described (pulling timing by grounding the timing lead to get idle) are classic-case mechanical timing misalignment. I'm going to go ahead and double check my timing marks tomorrow, but with the Jay racing timing tools I don't see how I could have screwed that one up. When assembling the engine I double checked all that stuff, spun the crank around a few times, checked again. Maybe my Fidanza gears aren't marked correctly, I'll verify by comparing them with a stock cam-sprocket.

Something else that didn't seem to make sense to him is that my ECU log is showing coolant temperature at 241 degrees. Which I guess isn't possible /ubbthreads/images/graemlins/dunno.gif I bought a 180 degree T-stat and new coolant temperature switch (signal feed for the gauge since I broke the tab off). Maybe I should trade in for a 192 degree T-stat and get a new coolant temperature sensor as well (ecu signal feed), then double check that I have the correct wires going to the correct sensors.

I'm really cutting it close now to be able to make the trip this weekend.
 

chucklesas

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Woops... I was using the wrong Hex value for my injectors. For some reason I was basing my calcs off 450cc instead of 440cc. Maybe that will help with that low fuel trim.
 

toybreaker

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Charles, sorry I couldn't be much help. /ubbthreads/images/graemlins/frown.gif

There's times I'll get to the end of a large project and some silly little thing I did at 3am the day before will keep me from lighting it up. Just having someone else eyeball things and ask some questions will jog something in my mind or they'll see something I didn't.

About the only suggestion I would have at this point is to light the car up with a stock set-up (450cc injectors/known good mas) to rule out an issue with the base set-up somewhere. I have a known good 1g and/or 2g mas, a cas, ignitor and socketed ecu and anything else you might need. You're welcome to borrow them if it'll help.

Quoting Charles:
I noticed on the TMO logger that when the throttle is fully closed the closed switch says "off", but shows "on" when the throttle plate is open. This seems reversed to me.



I would also look a little further into ^^this^^.

That's just weird. I've never used the tmo logger package. Can someone that runs it chime in with the low down on how it "sees" the closed throttle switch? I know the 90 model has a different, four pin harness that plugs in over on the firewall, so maybe something weird happened when the harness was reconstructed in that area. /ubbthreads/images/graemlins/dunno.gif

If you could just get the thing up and running and stabilised long enough to set up the timing, that would be a huge step in the right direction! That would rule out anything funky on the mechanical side, or in the wiring harness.

At any rate, you've covered most of the bases, and now it's time for an experts help...

Hopefully, Keydiver will come along and give his valuable imput. If there's one guy on this board that knows the code for these cars, it's him. /ubbthreads/images/graemlins/worthy.gif

[edit] I forgot to ask you about the fuel. Is it fresh, or has it been sitting for awhile?
 
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chucklesas

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It's been sitting for a while, I just couldn't figure out what to do with 8 gallons of 93 octane. If I can at least get it running well enough to get to the gas station and top off with some good fuel that will help me out a bit, too. I'm going to swap out all the thermostat housing bits (sensors, t-stat and double check the wiring... who's idea was it to run two yellow wires with green strip and two green wires with black strips to the same general area?).

I took the day off to work on this thing. So, off to the autoparts store I go.
 

toybreaker

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Quoting Charles:
who's idea was it to run two yellow wires with green strip and two green wires with black strips to the same general area?).



Bean counters, gotta love em. /ubbthreads/images/graemlins/tongue.gif

I've seen some creativity in those circuits during harness reassembly, so that's why I asked about it.

Since you have the factory manual, just ohm out the wires from the ect back to the specific ecu pin number, and repair as necessary.

Since you're already going to be there, might be a good idea to check the tps and closed throttle switch, as well as anything else you may think was changed during the harness recontruction/installation.

Good luck, and hope you get it up and running today!
 

chucklesas

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Getting closer. I replaced the gauge output sensor and ECU output sensor on the thermostat. I was seeing water temps of about 192 after I let the car idle for about 5 minutes with the timing lead grounded. Base timing has been set to about 5-7*. I swapped out my exhaust with the one that was 2 resonator pipes in line and replaced one of the gaskets, so no more exhaust leaks. I bled the brakes and finally got the car down on all 4 wheels.

I'm still having trouble to idle, but there are 2 more things I need to try to hopefully fix the problem. One is get to a gas station and get some good gas in the car. The second, and I think more importantly at this time is to figure out why I'm getting a Code 31 detonation sensor check engine code. I have a feeling it's because I had to splice in a new connector, because the originaly one on the harness was cracked. Anyway, I just found a non-melted connector from another harness that was similar and soldered it on there. Would this probably be why I'm getting the code? I guess the original wiring is shielded somehow, and since I spliced in this other connector and wiring I'm not fully shielded along the lenth of the wire? I thought it wouldn't matter, since the wire isn't shielded right at the connector anyway, but maybe I'm wrong, or I screwed something up if one of those wires really is a coax. Another thing, the knock sensor wires are black and red, I keep reading that they should be black and white. Maybe I have the wrong knock sensor?
 

iceman69510

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Don't worry about the color of the wires from the connector to the sensor, they can change. Only be concerned with the colors in the harness side.
 

chucklesas

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Argh, wrote up a bunch of stuff, but apparently I never hit add reply.

Code 31 is gone. I reset the ECU.
Python 880 injectors compensating for 840cc via ECU and 312 uS deadtime
Removed the Octane reset from my chip
Extended Maps
482 MAF

I double checked the mechanical timing marks. They appear to be close... the exhaust looks like it could be off (not quite 12 o'clock when at TDC). So I just retarded the cam about 2* using the adjustable gears. I don't really see how they could have been off though since I used the jay racing timing belt tools.

Anyway, I STILL can't get the car to idle at all. I'll check the plugs tomorrow. They are probably fouled up again.
I don't know what there is left to try.
 
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vr4play

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Are you sure you have your maf compensation correct in the chip. Are you sure you don't have a bad maf. I had that problem with a car I built. I umpluged the maf and the car ran just fine after it set the engine light and ran off the map in the ECU.
 

chucklesas

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I decreased dead time to about 216uS trying it out in 24uS increments from 330 down... the sweet spot seemed to be around 240-264. It helped a bit, but the car will still only idle when I lock the timing by grounding the timing lead. I drove it to the gas station and back. I thought I was going to die because I'd lose power brakes and power steering each time it stalled, and of course I hit every light between here and the gas station. Anyway, I've given up on trying to get it running for the Factory MOD event and will use my leave to go visit friends instead. I'll try to get another log in to view my low level fuel trim (should tell me if I need more or less deadtime), probably order some new injectors, find a new MAF, get a new Keydiver chip.

Time to garage this baby. Looks mean in black and white though.
 

toybreaker

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Quote:
I thought I was going to die because I'd lose power brakes and power steering each time it stalled,




If you lose vacuum assist as soon as the motor dies, there's something else going on...

As delivered from Mitsubishi, these cars had enough booster area for at least three applications of the brakes before enough vacuum is vented that you lose the power assist, (provided the vacuum is being preserved in the booster)

There is a vacuum check valve in the brake booster hose from the factory. It's role in lfe is to seal the vacuum in the booster, and when it fails (or is missing), you get the symptom you are describing.

Occaisoinally, the booster diaphragm can get a pin hole/other defect that allows the vacuum tbe vented, the spool valve can stick or some other defect can take away the power assist.

Best test for this is to pump the pedal, engine off at least ten times to relieve the vacuum.
With your foot on the pedal, Light the motor up.
The pedal shoud drop considerably.
Release the pedal, let it idle for a sec.
Turn the engine off and wait thirty secs or so.
Apply the pedal, and their shpu;d be full assist.
Release and then Apply the pedal again, shoukd be ~ full assist,
Repeat a few times...
About the third or fourth time, you'll notice the pedal getting harder.

I would recomeend you do this befre you go much further troubleshooting your other issues.

If you replaced the booster feed hose t might be as simple as a missing check valve. It could also bea torn/melted booster diaphragm that was collateral damage from the engine fire. /ubbthreads/images/graemlins/dunno.gif

Problems with vacuum systems will most definately affect your running issues .
 
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