Very Bad MPG after tune
Very Bad MPG after tune New to HPT. I haven't flashed the ECU or done anything other than scan up to this point. Just alot of reading and videos. A very popular and well respected tuner tuned my car years ago and the car rips at WOT but I'm lucky to get 10 MPG (City) and maybe 20 (hwy) driving normally. The old tune I had before this one would hit 30 MPG on the highway and near 20 city.
Would anyone be willing to have a look at my tune and provide feedback on why they think I might be getting terrible fuel economy? Details in sig. I'm running the white GXP injectors FYI.
Would anyone be willing to have a look at my tune and provide feedback on why they think I might be getting terrible fuel economy? Details in sig. I'm running the white GXP injectors FYI.
Attached is a log from a couple of weeks ago. I just setup my analog wideband yesterday so I'll upload a new log with wideband data in the next couple of days. I had another tuner tell me that incorrect injector data was used on this tune however I'm not sure if that's true and if it is, perhaps it may be intentional?
Thanks in advance for the feedback.
Thanks in advance for the feedback.
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TECH Fanatic
Joined: Dec 2017
Posts: 1,470
Likes: 267
From: Bossier City, Louisiana
Its advisable for all of us here on the site to keep rigorous copies and backups of all of our tunes. Make your tuner provide you a copy of the old tune before he modifies it into something unrecognizable - tuner lock passwords also strictly forbidden.
Same for a backup copy of your tune that you have in use. Put them both on a thumb drive and then safely store it all away.
Rick
Same for a backup copy of your tune that you have in use. Put them both on a thumb drive and then safely store it all away.
Rick
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Yup, looks like you are in SD and the VE table needs some attention. Currently looks super fat in the cruising areas 12-24% off. Your WOT is a little on the lean side (some spark knock),but that can be debatable.
I'd start off with the right injector data first.
It's no where close compared to the white GTP injector data that's listed in the injector sticky.
The VE is way lower than what I would expect with a cam that size, my guess, and without more logs that's all it is, it's low because the injector data isn't right.
That timing curve is aggressive AF too.
It's no where close compared to the white GTP injector data that's listed in the injector sticky.
The VE is way lower than what I would expect with a cam that size, my guess, and without more logs that's all it is, it's low because the injector data isn't right.
That timing curve is aggressive AF too.
OK, this is useful feedback fellas. The car is tuned in SD, so no MAF data. The car runs well at part and full throttle but had a stalling issue (while coming to a stop) that we addressed a few times. It still stalls once every few drives. I think the tuner made some outside of the box maneuvers to combat the stalling. Would purposely modifying the injector data be used as a tuning technique?
I'll log again tomorrow and add the PIDS mentioned above. It's a 98' ECU if that means anything.
Thanks for the feedback.
I'll log again tomorrow and add the PIDS mentioned above. It's a 98' ECU if that means anything.
Thanks for the feedback.
Typically incorrect injector data ends up causing all sorts of other tuning problems.
It also has a lot more base running airflow than what I would expect to see too. All the idle adaptives are on too.
Id be interested to see what the IAC counts, STIT and LTIT are.
Speaking of LTIT, make sure you add that PID too. With the idle adaptives turned on, that needs to be logged too.
Everyone has a different way of doing things.
It also has a lot more base running airflow than what I would expect to see too. All the idle adaptives are on too.
Id be interested to see what the IAC counts, STIT and LTIT are.
Speaking of LTIT, make sure you add that PID too. With the idle adaptives turned on, that needs to be logged too.
Everyone has a different way of doing things.
Delete the MAF channels. I posted that channel list before I realized it was running in SD.
Other than that, it looks like you have everything you need, just make sure you add your WB.
Other than that, it looks like you have everything you need, just make sure you add your WB.
Sounds good. I'll add the WB and take it for a spin tomorrow and log. Another thing worth noting, I get ALOT of burble/pops on decel. I assume that is related to the excessive fuel consumption.
New log from this morning. Ambient temp was 36°. The more I learn, the more I think I'm going to need to build a completely new tune. Starting with the correct injector profile. I have a ton to learn before I even think about flashing the ECU.
Let me know what you guys think after reviewing the new log.
Let me know what you guys think after reviewing the new log.
I think that would be a good place to start.
If you use the histogram data to adjust the VE table., it's ridiculously low.
With it idling at 55kpa, IMO, there is no way the VE is right, which points to the injector data.
If you use the histogram data to adjust the VE table., it's ridiculously low.
With it idling at 55kpa, IMO, there is no way the VE is right, which points to the injector data.