Negative Mid LTFT and more issues!
#16
Is there a way to check fuel pressure on the stock setup? I believe I have a feeling issue but I don't want to spend $250 on a AFPR setup just to find out is something else. Plus, all of the reading I've done indicates that a Walbro 255 shouldn't overrun the stock regulator like I'm seeing.
On a side note is anyone willing to take a look at my rom to see if it is something in the tune?
On a side note is anyone willing to take a look at my rom to see if it is something in the tune?
#17
EvoM Community Team Leader
How is the pump wired? If it has been bypassed and does not preserve the factory low voltage circuit it could be over running the regulator at low loads / idle. Also there are tables that control how much extra fuel is injected based on tps delta. Unfortunately there is no factory pressure sensor so you would have to install something.
#18
How is the pump wired? If it has been bypassed and does not preserve the factory low voltage circuit it could be over running the regulator at low loads / idle. Also there are tables that control how much extra fuel is injected based on tps delta. Unfortunately there is no factory pressure sensor so you would have to install something.
I don't think this could cause my problem but I'm not sure my IACV is working because when I removed it from the throttle body and turned the key I didn't hear it move or make any noise. To be fair I bought a cheap one and tested it and it didn't make any noise or move either. Also, both tested prefect on my volt meter (all right about .30 ohms).
Finally, my battery is low / weak. Could that be a contributing factor?
Thanks for the input and keep it coming!
#19
EvoM Community Team Leader
Low voltage will cause problems unless your tuner specifically tuned the car for those voltages. the ECU has a lookup table for the injector latency (dead time) based on voltage. So at different voltages it uses different dead times. If the dead time wasnt tuned for that specific voltage/injector it could be way off and throw everything outta whack. The alternator should be pumping out ~14.6 volts while running though, if you arent seeing around this voltage while the engine is running then you have some other electrical problems too.
#20
Low voltage will cause problems unless your tuner specifically tuned the car for those voltages. the ECU has a lookup table for the injector latency (dead time) based on voltage. So at different voltages it uses different dead times. If the dead time wasnt tuned for that specific voltage/injector it could be way off and throw everything outta whack. The alternator should be pumping out ~14.6 volts while running though, if you arent seeing around this voltage while the engine is running then you have some other electrical problems too.
Looking at the log I posted in my first post my battery voltage never even read higher than 13.8. I recently checked the voltage at the terminals and it read pretty low. I was shocked the car turns over. I'll check the voltage again tonight and see what it is.
Could my battery be the cause of my car running rich?
#22
Another thing to mention is that the latest tune I'm using does not go into closed loop. My tuner couldn't figure out why my car is running so rich so he set it to but run in closed loop. To be fair, at the time, I thought I still had a stock pump. I let him know recently that it turns out I have a Walbro but he hasn't responded and doesn't look like he's going to send me another tune. So that's why I'm trying to figure this out on my own.
#23
EvoM Community Team Leader
I would definitely replace the battery if its reading less then 12ish volts with the car off. with the car on and everything running the voltage at the terminals should read over 14 volts. I don't want to speculate too hard that this is your problem, but it is a problem. I would also suggest comparing your "Battery Voltage Latency Compensation" table values in your tune to what the suggested values are for your injectors (there is a mega thread with scalings/latency for most injectors). You might find some red flags there. 13.8 volts doesnt really set off a red flag to me as there is some voltage drop in automotive systems, but what you measure at the battery terminals will tell a more complete story. The ISCV doesn't really make noise, but you can log ISCV steps in evoscan to see what its doing and how thats effecting idle.
#24
EvoM Community Team Leader
sorry i just reread your first post, you are on stock injectors, so stock values should be used, and they should work well as they where determined by the OEM.
#25
I would definitely replace the battery if its reading less then 12ish volts with the car off. with the car on and everything running the voltage at the terminals should read over 14 volts. I don't want to speculate too hard that this is your problem, but it is a problem. I would also suggest comparing your "Battery Voltage Latency Compensation" table values in your tune to what the suggested values are for your injectors (there is a mega thread with scalings/latency for most injectors). You might find some red flags there. 13.8 volts doesnt really set off a red flag to me as there is some voltage drop in automotive systems, but what you measure at the battery terminals will tell a more complete story. The ISCV doesn't really make noise, but you can log ISCV steps in evoscan to see what its doing and how thats effecting idle.
I'm not sure where to go from here. Any other suggestions?
#26
EvoM Community Team Leader
Replace the spark plugs, make sure you gap them to the appropriate gap for your boost level. They are easy and cheap to do and you are running so rich i wouldn't be surprised if they are fouled pretty good. When you pull the battery it should reset the trims if you arent going into closed loop they shouldn't change after that. See what the AFR's are doing after resetting the trims, replacing the battery and new plugs. Based on your log i wouldn't really push to hard on the fuel pressure being a problem as your idle trims would be the most screwed up if that was the case, but they actually look pretty normal.
#27
EvoM Community Team Leader
I have never tuned SD on an evo but I know that SD is way more sensitive to tuning then MAF so getting a second opinion on the tune itself would also be high on my list, and after swapping the cams you probably need an actual retune and not just some adjustments not based on actual logging. I believe you said your tuner just sent you a rom that was suppose to adjust for the stock cams, but im assuming that it wasnt adjusted based on an actual tuning session?
#28
Replace the spark plugs, make sure you gap them to the appropriate gap for your boost level. They are easy and cheap to do and you are running so rich i wouldn't be surprised if they are fouled pretty good. When you pull the battery it should reset the trims if you arent going into closed loop they shouldn't change after that. See what the AFR's are doing after resetting the trims, replacing the battery and new plugs. Based on your log i wouldn't really push to hard on the fuel pressure being a problem as your idle trims would be the most screwed up if that was the case, but they actually look pretty normal.
#29
EvoM Community Team Leader
As far as i know and have experienced the trims will not adjust without the car going into closed loop. This is why its a pain to dial in injectors because you have to let it sit for a while before it will go into closed loop and begin adjusting the trims so you can see where you are at. The LTFT mid needs some highway cruising before it will go into closed loop and begin adjusting. Seems like the ball is definitely in your tuners court on this one. I would also strongly encourage you to read up and try your hand at fixing this yourself. Learning to tune is a lot of fun and very rewarding, and you aren't stuck relying on other people (as you have found yourself). I know its a deep rabbit hole and most people just wanna pay a "professional" to do it right (in theory anyway) but self reliance has its perks.
#30
As far as i know and have experienced the trims will not adjust without the car going into closed loop. This is why its a pain to dial in injectors because you have to let it sit for a while before it will go into closed loop and begin adjusting the trims so you can see where you are at. The LTFT mid needs some highway cruising before it will go into closed loop and begin adjusting. Seems like the ball is definitely in your tuners court on this one. I would also strongly encourage you to read up and try your hand at fixing this yourself. Learning to tune is a lot of fun and very rewarding, and you aren't stuck relying on other people (as you have found yourself). I know its a deep rabbit hole and most people just wanna pay a "professional" to do it right (in theory anyway) but self reliance has its perks.