VVT motor lean and die
06-01-2018, 03:03 AM
#21
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Shouldn't be battery. Are you using an NA alternator?
I would measure voltage at the battery and injectors to confirm it matches what the ecu is seeing.
Voltage differences can make a pretty significant change in fueling but AFAIK that shouldn't be an issue if the ecu is seeing the same voltage as the injectors and the injector dead times are set correctly.
I would measure voltage at the battery and injectors to confirm it matches what the ecu is seeing.
Voltage differences can make a pretty significant change in fueling but AFAIK that shouldn't be an issue if the ecu is seeing the same voltage as the injectors and the injector dead times are set correctly.
Is there any other weird reason the injectors wouldn't be getting the same voltage? I'm just assuming the dead times have been correct since it's not something that was changed since it started running poorly.
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06-01-2018, 03:30 AM
#23
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Eh bad news I guess? Injector dead time is the same across my tune and the MSPNP base map.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
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06-01-2018, 05:50 AM
#24
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Eh bad news I guess? Injector dead time is the same across my tune and the MSPNP base map.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
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06-01-2018, 12:13 PM
#26
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Eh bad news I guess? Injector dead time is the same across my tune and the MSPNP base map.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
I feel like the drop in voltage could definitely be affecting the injectors though. But I don't know what would cause that. I guess this is where my knowledge ends and I try to learn from you guys and more research.
I'm still pretty confident a totally flat deadtime curve will cause your issue. You still need to figure out why your voltage is sub 13 when running too.
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06-01-2018, 12:20 PM
#27
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That is not the deadtime curve I saw in the DIYAutotune basemap for 94-95. MegaSquirtPNP by DIYAutoTune.com
I'm still pretty confident a totally flat deadtime curve will cause your issue. You still need to figure out why your voltage is sub 13 when running too.
I'm still pretty confident a totally flat deadtime curve will cause your issue. You still need to figure out why your voltage is sub 13 when running too.
Could my alternator be going out? My battery is only a year old. I'll try and find more reasons I would suddenly have slightly lower voltage.
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06-01-2018, 12:27 PM
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It's very possible your alternator is bad. As I said before it shouldn't be a battery issue. Since it's an NA alternator it's internally regulated so there isn't really anything outside of it that would cause lower charging voltage. Measure voltage at the battery while running to make sure it matches what TS shows.
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06-01-2018, 12:37 PM
#30
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Yeah don't do that. Inputs and outputs are potentially different as the harnesses are different. AFAIK you should be using the 94-95 basemap and making changes to that in order to run the vvt engine.
It's very possible your alternator is bad. As I said before it shouldn't be a battery issue. Since it's an NA alternator it's internally regulated so there isn't really anything outside of it that would cause lower charging voltage. Measure voltage at the battery while running to make sure it matches what TS shows.
It's very possible your alternator is bad. As I said before it shouldn't be a battery issue. Since it's an NA alternator it's internally regulated so there isn't really anything outside of it that would cause lower charging voltage. Measure voltage at the battery while running to make sure it matches what TS shows.
I'll measure battery voltage while data logging today and see if they're the same.
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06-01-2018, 01:48 PM
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06-07-2018, 07:39 PM
#32
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Hey just wanted to update this thread in case someone else has this problem some day.
It did end up being the alternator. Got it replaced with an AC Delco reman and everything has been running much better.
Found out not only from you guys in the thread, but as I was looking over a couple other things, the battery was too low to start the car again. My roommate suggested jumping it for me to help me out. While the battery was connected to his, the car started and ran just like I wanted it to. Also when he parked it behind my car and shut the door, he habitually locked the door and left the keys in the ignition. So when the AAA guy showed up (because no spare key) my roommate asked if he could test my battery and alternator. Lo and behold, the alternator was NOT sufficiently charging the battery.
Thanks a lot for the help guys, especially Spartan for sticking around so long, lol.
As for using the base map appropriate for the motor and not the harness/chassis, I donno what to tell you guys. It started up really well the first time after the swap, and now my tune is built around it. Spark timing has been adjusted all over the map as well. I appreciate the notice though.
It did end up being the alternator. Got it replaced with an AC Delco reman and everything has been running much better.
Found out not only from you guys in the thread, but as I was looking over a couple other things, the battery was too low to start the car again. My roommate suggested jumping it for me to help me out. While the battery was connected to his, the car started and ran just like I wanted it to. Also when he parked it behind my car and shut the door, he habitually locked the door and left the keys in the ignition. So when the AAA guy showed up (because no spare key) my roommate asked if he could test my battery and alternator. Lo and behold, the alternator was NOT sufficiently charging the battery.
Thanks a lot for the help guys, especially Spartan for sticking around so long, lol.
As for using the base map appropriate for the motor and not the harness/chassis, I donno what to tell you guys. It started up really well the first time after the swap, and now my tune is built around it. Spark timing has been adjusted all over the map as well. I appreciate the notice though.
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06-07-2018, 08:46 PM
#33
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The potential problem with using the 01-05 basemap is that the inputs and outputs are set up differently. If everything is working correctly then don't worry about it.
You need to fix your injector deadtime curve. That part of the basemap is definitely messed up.
You need to fix your injector deadtime curve. That part of the basemap is definitely messed up.
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