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MerloZ

Help. what is wrong with this tune.

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Hello,

Can anyone smarter than me take a look at this tune and tell me what is wrong with it for my build.

I have a pretty much stock 82 l28et 

stock injectors

DIY wiring harness i put together.

iac sensor

240sx 65mm throttle body and tps

DIY trigger wheel

single coil

lc2 wideband (not wired to ms2)

walbro 255 lph inline fuel pump

no other sensors are connected to the MS2

Ive been messing around with some other peoples tunes and came up with this.

This started  the previously warm car yesterday and i set my timing on the car with this project. its set to around 19 btdc because it was running so rough. The car was running very rich and was backfiring with every change in throttle. i assume the ignition settings might be wrong and the fuel map is too rich. ive scaled down the fuel map and it didnt seem to change much at all. could their possibly be other more hidden settings that i also have to change. Today i tried to start it and it just kept flooding itself no matter what spark settings i change or if i scale down the fuel map. Im new to this type of stuff so any help is apreciated. ive been researching so much and tried so many things but nothing is working. thankyou.

 

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You have to attach a file for us to view or take tons of screen shots.

 

First the basics, what version megasquirt, MS2 v....

 

You don't have an intake air, coolant, o2, or TPS sensor connected?

 

Your off to a pretty bad start there. It sounds like you are trying to blunt force the ECU into controlling fuel without any closed loop logic involved and no external trim sensor inputs. Technically you could get the ECU to control for that, but at that point you might as well be running a driver box with dials.

 

First go to test mode and disable fuel or pull the fuel pump plug we don't want to flood the motor. 

 

Check the timing on the crank and the distributor then check the cam to make sure you aren't 180* out. Crank the car and check your timing mark on the crank. If I recall you can't install the wheel incorrectly on the distributor, but your distributor offset could be off or could be off with the drive gear. Double check the timing with a timing light. Find out the offset and input it into the setting.

 

Make sure to enter the correct settings for the optical wheel.

 

Hook up the other sensors. The ECU uses those to bias the fuel trim. You are going to have to find calibration curves or sit there and generate them with a thermometer and a multimeter.

 

Once you have confirmed you are getting signal from the sensors and the ECU can control the fuel and the spark, then get around to re-enabiling the fuel pump and start messing with the base settings.

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Is there a reason you are not using coolant temp sensor?

 

I'll check back for the tune file in the evening.

 

Unfortunately there are a lot of reasons why this can be happening. First things are to make sure we are on the correct baseline. Make sure timing is correct and firing in the correct spot, then test the injectors. Finally we look at the tune file and can mess around with that. If you have a file for a stock L28et and you mess around with the VE values you could be trying to tune out a physical problem electronically, like excess fuel pressure.

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Is there a reason you are not using coolant temp sensor?

 

I'll check back for the tune file in the evening.

 

Unfortunately there are a lot of reasons why this can be happening. First things are to make sure we are on the correct baseline. Make sure timing is correct and firing in the correct spot, then test the injectors. Finally we look at the tune file and can mess around with that. If you have a file for a stock L28et and you mess around with the VE values you could be trying to tune out a physical problem electronically, like excess fuel pressure.

No real reason i dont have a coolant sensor. i guess i didnt feel like tapping a 3/8 hole but today i realised how dumb im being so i went to NAPA and got one with a pigtail just a minuete ago. im going to connect that today. is it a bad or good idea to leave the lc2 seperate from the ms2 for now or should i connect it to the wiring harness. Right now its just going to the gauge. Also is it possible that my walbro 255 lph pump is making too much pressure even if the stock fpr is working? i was thinking that could be why its rich also. Here is the file.tune.zip

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You tap into the o2 signal so megasquirt gets a signal it should be a pink wire labeled o2 on the megasquirt harness.

 

Depends on the flow capacity of the lines and the FPR. If it can't bleed out the volume you aren't using it is just going to build excess pressure, the excess pressure only has one route which is through the injectors. A fuel pressure gauge would tell you if that is problematic.

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You tap into the o2 signal so megasquirt gets a signal it should be a pink wire labeled o2 on the megasquirt harness.

 

Depends on the flow capacity of the lines and the FPR. If it can't bleed out the volume you aren't using it is just going to build excess pressure, the excess pressure only has one route which is through the injectors. A fuel pressure gauge would tell you if that is problematic.

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Okay so i couldnt really test anything today. I was installing the gm coolant temp sensor and i cracked the friggin housing. I started to wire the piggy for it. When i get time i will also wire in the o2 sensor. Today was i had some time but now i wont have time till thursday or friday. Thankyou for the quick replies its very very apreciated and im super glad your helping me out. Did you look at the tune file.

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Nope at work won't be able to look at it till evening. 

 

Yea, chances are a japanese motor from 30 years ago isn't going to use american NPT. Probably needed an NPT to BSPT adapter as that seems to be what they used over there.

 

I can look over the settings, but really without a log file it will be hard to tell what the car is actually doing. A log file will be useless without an o2 reading so we need to get that input into it asap.

 

5mm is less then a quarter inch. If you are pumping 255lph, that is roughly 60-70 gallons per hour? Given a gallon/hr is usually good for about 10hp, you are flowing 600hp worth of fuel through, A: a very small line, and B: an even smaller return line. I think you should probably get a fuel pressure gauge installed to see if you are just over pressurizing your system. 

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That setting is correct to what my tune file says i saw that and it looked wrong and i know 269cc is the correct number but that file came from another person so i figured id better not mess with something that suposedly worked for someone else.

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That needs to be changed...It looks like it has a base value for the injectors to fire in ms, but that could be completely wrong. 

 

Depending on version sometimes those settings don't carry over correctly so the tune file is generally used just for the VE table and the ignition table. It is up to you the end user to go over the settings. In fact if you go back far enough you will actually find that the axis were inverted and copying directly over would be very problematic if it would even let you.

 

Go ahead and start looking up the actual information for the settings. 

 

Since you are going through the effort, might I suggest reporting back here with your findings for others?

 

Things you need to look up:

Engine size in CC (it won't be exactly 2800cc)

Injector size in CC 

Injector characteristics (dead time, etc I believe there is a chart somewhere in this forum)

Optical wheel settings (should be on DIY's page)

 

Once you have those settings entered, you would disable the fuel pump, then confirm your spark via a timing light and a physical inspection of the crank pulley to cam correlation when it is lighting off the correct cylinder.

 

Then you need to verify the fuel. The concern is, can the lines cope with what you are throwing at it? Looks like this is in a 260z (helpful information to include), and that fuel line size seems suspiciously like the stock lines. I think you need to look up how people do their fuel lines in these swaps it usually involves using the stock feed line as the return and installing an even larger line as the feed. A fuel pressure gauge will tell how well the system is coping with the fuel flow, I imagine not well.

 

Those are the basics to setting up megasquirt as well as hooking up all the sensors before even attempting to get to this stage. 

 

I do need to verify since there are no pictures or anything, you aren't doing anything silly like twist and tape are you? If so you are going to be fighting gremlins down the road. 

Edited by seattlejester

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Okay thankyou i well get working on all that tomorow. I did copy the tune file to my version but alot of stuff didnt work so. I physically copied every single setting. Is that okay?. Obviously some are wrong probably due to the axis being inverted and similar stuff like that, that just doesnt correspond with the new version. I used jb weld on my thermostat housing and looks like it is gonna do the trick. (For now at least). And no im not twisting the wires that would be a nightmare oh my god. Im using heat shrink crimps. I would solder them and heat shrink them but ive never gotten the hang of that. So tomorow if all goes well it will be wired up to all sensors. I will test fuel pressure. And possibly get a log file if i can get i to run again.

 

If i have time i will find all the proper specs and settings and post them here. I know most of them right now but ill wait till i have them all.

 

However the inletand outlet of the FPR are only like quarter inch line so how could adding a bigger pressure and return line create any difference until i switch FPR's. Also anyone know of good FPR's that wont out a hole in my pocket.

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This is just a few pics of my car/ engine.

74 late model 260z. Got it when i was 15 fully restored it in a little over a year aside from tranny and engien rebuilds. However now it obviously has a rebuilt engine. The engine swap was the winter project. The car was in terrible condition rust and body wise. I did about 90 percent of everything myself. But could have done i all i was just determined to drive it to a car show. And i did without brakes haha.

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post-53871-0-65755200-1492038247_thumb.jpg

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Thanks for that, you just never know what someone finds acceptable.

 

Copying over the settings should be fine as long as the person before isn't doing something like compensating for a physical problem as well. Really you should be going over each setting and seeing if that makes sense. For one it is a good exercise to see if you understand what the inputs are, and two it will be helpful if a friend goes megasquirt down the road as you will know what each setting does.

 

Excellent that should get us to see how the engine is running. Really though one of the first questions that will pop up if you have problems are fuel pressure and timing so getting those two parameters set will be very helpful. I'll keep looking through the file and see if I run into anything else odd that might be holding you up.

 

So for future reference you have an MS2 v3.0 an original B&G 2005 board that was assembled by DIY autotune. If I'm not mistaken it looks like it has the expansion board thingy? I'm not all too versed in the physical aspects of it, but that looks like what people call the expansion board on there. Don't see any wires in the proto area so probably no mystery drivers and such.

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Thanks for that, you just never know what someone finds acceptable.

 

Copying over the settings should be fine as long as the person before isn't doing something like compensating for a physical problem as well. Really you should be going over each setting and seeing if that makes sense. For one it is a good exercise to see if you understand what the inputs are, and two it will be helpful if a friend goes megasquirt down the road as you will know what each setting does.

 

Excellent that should get us to see how the engine is running. Really though one of the first questions that will pop up if you have problems are fuel pressure and timing so getting those two parameters set will be very helpful. I'll keep looking through the file and see if I run into anything else odd that might be holding you up.

 

So for future reference you have an MS2 v3.0 an original B&G 2005 board that was assembled by DIY autotune. If I'm not mistaken it looks like it has the expansion board thingy? I'm not all too versed in the physical aspects of it, but that looks like what people call the expansion board on there. Don't see any wires in the proto area so probably no mystery drivers and such.

Correct i have an Ms2 v3.0 but i assembled that myself. i ran into some trouble but its back to working order thanks to Matt at DIY. Yes the expansion board you are talking about i believe is the ms2 daughter card. there is no added on mystery drivers aside from the spark setup DIY told me i needed for the l28et dizzy.

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Here are the specs for my setup

engine-  2,753 cc 

stock l28et Injectors- 259cc

TunerStudio settings (Batch fire / wated spark or single coil)

  • Settings under Basic Setup -> Tach Input / Ignition Settings:
    • Spark mode: Toothed Wheel
    • Ignition input capture: Falling Edge
    • Spark output will depend on what output setup you’re using. BIP373s and QuadSparks both use Going High / Inverted.Getting this setting wrong can damage the ignition module and/or coils. If the ignition module or coils get hot with the key on and the engine off, turn the key off immediately and select the opposite output setting.
  • Settings under Basic Setup -> Trigger Wheel Settings:
    • Trigger wheel arrangement: Single wheel with missing tooth
    • Trigger wheel teeth: 12
    • Missing Teeth: 1
    • Tooth #1 angle: 345 (This varies slightly between individual engines. Check with a timing light and adjust as needed.)
    • Wheel speed: Crank wheel

Injector specs (found on this forum) noteven sure what they mean yet lol.- Topen(MS)-1.2 PWM current limit-30% PWM threshold(ms)- 1.5

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Too late to the party, but GM sells a temp sensor that is 12mm x1.5 thread pitch. Screws right into the stock L28 housing. Maybe pick up a new or used L28 lower stat housing and start over. I'll look up the part number a bit later. 

 

Edit: Standard Blue Streak part number for 12mm x 1.5 GM CTS is TX89. OEM GM part # is 15326388 or 15369305 . I would recommend ordering genuine GM sensor or AC Delco ( Delphi brand ) as the sensor calibrations are bang on with these. Aftermarket brands vary in specs quite a bit. 

 

Your LC2 wide band should be connected to your MS. Get that handles as Chris ( I think it's Chris??  ) mentioned. It will make tuning so much easier. 

 

Working on an improved Tune file for you that should be a safe running baseline. You will still have to set your Trigger offset properly and set timing. This should get you up and running but it is in no way a final tune. Log everything, especially AFR and do not raise boost above 5 psi, until Tune has been further refined. I take no responsibility for what this tune will do to your engine. Use at your own risk. But I've made it fairly conservative. Look it over for any glaring faults before using. Will edit post and upload tuning file later in the day.

 

BTW, what are you using for a boost controller? MS Boost controller, Auxiliary Electronic Controller or Manual Boost Valve?

Edited by Chickenman

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