Throttle Trouble

[xxblamedxx]

2013 Ford Mustang GT
LT Headers, cat delete, Roush CAI, FRP 47Lb injectors, upgraded fuel pump, on pump E85. In our area I have measured the E for years at 68-70% Alcohol. Everything else stock.

I am having an issue that has me completely baffled. I am not an expert tuner on these Mustang, but I have done several and not seen this behavior.

I logged on the dyno look at pedal % vs TB CMD vs Actual. It stays in sync until about 30* throttle and 30% pedal. Then the pedal keeps increase, but the TB CMD stays constant until later in the run then the TB jumps up suddenly. I have tried a dozen different things in the tune. I should not be having this issue on a stock TB.

On the street it shows up as a surging. I did not log pedal, but you can see the saw tooth pattern in all the other parameters. I put a new TB and MAF and it still does it.

Also, the guy cam in with a BAMA E85 tune. When I put that tune on it at around 30% pedal the TB jumps straight to WOT. On the BAMA tune it is very twitchy. HPTuners will not read the BAMA tune so I can not compare.

The guys is not happy with his BAMA tune, says it starts hard. I am tuning it for nitrous, but I am trying to get the E85 part of my tune dialed in before I put the nitrous on it.

Throttle Pic.PNG
surge while driving.hpl
8-15-2020 Rev2.hpt
Sudden jump to 80 THROTTLe.hpl
BAMA Tune Log.hpl

[small tuner]

this tune for E85 or pump gas ?

[xxblamedxx]

The posted tune is for pump E85 (~69% alcohol)

[small tuner]

Then you need to adjust Fuel stoich ratio or enable flex fuel and calibrate related tables.

[xxblamedxx]

I need help with the TB not opening. The E85 part of the tune works fine. No trouble with fueling.

I have tried adjusting the slope, the WOT count, the RPM vs angle, ETC predictive angle, etc... Everything I try makes it worse. TO the point it triggers the wrench light.

[nicks1031]

The tune file you posted looks all kind of messed up. MAF data is astronomically off for an NA car. TB model is all hacked up if this is a stock TB. My advice, start over with a stock file and keep it simple.
Utilize the flex fuel logic, its not terribly complicated and works really well.

[Witt]

I agree with the guys who posted above. The fueling side is really hacked and the error would have to be baked into the airflow side. A Roush CAI uses a stock MAF transfer, this isn't anywhere close. Stoich is set incorrectly, injector data doesn't look right to me. I'm honestly surprised it even starts. No way would you get any kind of expected throttle response.

I would definitely start over from stock.

[xxblamedxx]

The injector data is copy pasted from the ford racing site.

The MAF is adjusted for the fueling on E85. When I enabled Flex fuel I could not get the AFR where I wanted it.

I will start over with the same injector data but enable flex and set stoich to 10.7 for ~68% alcohol.

[Witt]

The injector data is copy pasted from the ford racing site.

Use the data from an 11-14 roush tune.

The MAF is adjusted for the fueling on E85. When I enabled Flex fuel I could not get the AFR where I wanted it.

Don't do that. You may get away with it on GMs, it will not work on Fords. This is the source of your throttle problems.

I will start over with the same injector data but enable flex and set stoich to 10.7 for ~68% alcohol.

Leave flex disabled. Set the stoich to the correct value for the fuel you are using. Only enable flex after you have finished dialing in the rest of the tune.

[xxblamedxx]

Did what I said and it stopped surging. Everything seems to be working not. Had the stuck in "cold start" copied the gas tables in and it started working. I also started hitting the pre-ignition timing table during pulls. I have no idea why. This is my first E85 tune on a Ford so it does strange things in my opinion.

Witt can you be more specific about dialing in the rest of the tune? It is more or less stock so there is not much to dial in.

Now the trouble is that I can not get it to shift where I want it to. Disabled shift anticipation and it made it better but it still shift really early. I am going to post in another thread about that problem.