How much does correct MPH affect tune? Tuner quit on me

[dmax5o]

My car is currently being tuned and was hoping the experts on here could give me some insight. It is a Gen1 Coyote Crate motor with Ford Racing Control pack version A manual transmission. The car has been tuned NA for 7 years and has run flawlessly. I finally got around to adding a turbo I needed a new tune.

Issues my car was having with new tune.
-Stalling when coming to a stop

On Rev9 the tuner gave up and blamed my combo (which ran perfectly on previous tune with turbo installed and boost set at 0)

After he quit I figured out how to look at a DL myself and immediately noticed a MPH discrepancy. Logs showed my car at 0 mph until actually going 25mph and when at 7k rpm in 3rd showed 35mph in the log. Back in the early days of GEN 1 Coyote swaps stalling was a common issue. Ford Racing discovered it was the lack of a speed input so they would send you two pins to input speed to the ECM and the problem was solved. Knowing this but not wanting to ruffle feathers I asked the Tuner if the mph being off could be the cause of the stalling issue. The tuner quickly sent me a change so mph now matched. Lo and behold the car no longer stalled once mph was correct.

Now, I discovered this myself after Rev 9 and suspect all the changes that were made chasing issues were because of the MPH and are still in the current tune. I would expect that after the realization of the speed issue the tuner would have started over with a clean slate but I don't know exactly what would have been affected and if this would be necessary? I am wondering what changes may have been made, if they could be the cause of the current issue and what other areas would be affected.

The current issue is, after a cold start any throttle input around 1500-2000 rpm to normally accelerate results in lean popping and bucking. Timing goes below zero and STFT shows 35% fuel added with Lambda around 1.5. i.e. it's lean.

Thanks for any help.

[veeefour]

Hit me up, I never give up...never had to.

This could be multiple of things. Need to dig into the tune.

[dmax5o]

Okay, I'll keep you in mind. Tuner is back. After I removed the turbo and it still did it NA he started looking again. Only happens after a cold start. MAF was swapped, O2 were swapped. Car runs fine other than this one area so that's why I don't think it's hardware but changed the stuff anyway.

[edcmat-l1]

Awfully hard to answer questions with no tune file or data log to look at.

[Alex5.0]

I had a customer with a big name tuner with rev7-8-9 etc... that was running poorly .

[dmax5o]

Well the tuner wouldn't give out the tune file so that's not an option. I can attach a DL. I now know what is happening just not why. What is happening is as I tip in at low rpm load goes up to 1.1 so it pulls from the load vs rpm table a -8 of timing so of course it won't run. The question is why would load be so high. I don't think it is any hardware because a log with the old SCT tune shows load around .5 under the same conditions so it runs fine because timing is around +17.

Is there something that could be messed up in the tune file (which we won't be able to see) that could cause this load issue?

[veeefour]

Its a tune, probably hacked torque model or speed density.
Or turbo is spooling this way and tables are not ready for low rpm high load conditions

[dmax5o]

Thanks, that's what I was thinking. Here is a log of the issue. Check out the third peak of TPS as it just stuck there at 1200 rpm. Tuner says the car was making boost because air load was 1.14 but I log boost and this turbo doesn't make any boost until above 3500 rpm at WOT and this is happening just barely touching the throttle

[murfie]

MAF signal looks horrible. Probably why your tuner is struggling. It takes some real care to even get something like this to work, and it will never work well reading values jumping around like it is.

Your original post said its lean, but this log shows its pegged rich and can't pull enough fuel out to even correct all the error the sensor is seeing.

The MPH should definietly be corrected through gear ratios, final gear ratio, tire size, whatever is out that is causing that.

Stutter new plugs.png

[veeefour]

What Murf said its correct - MAF signal looks dirty but this is sometimes the case with turbos. Some IC and piping are just "turbulent" to say the least.

Another thing is your spark tables are just bad, you start with "negative timing" (and you really shouldn't) hence you go rich as fuel is not burned properly.

Overall like I said, this is 100% tune.

[dmax5o]

Thanks for the replies fellas. You're right, that DL attached does show rich. That was after we had tuned some more. Here's the earlier one I was referring to where it is rich at idle but as soon as the throttle starts opening it goes lean. Does the MAF look dirty all the time to you? I thought it might be a result of how the engine was running....a little rough and when I pressed the throttle it felt like a car with a distributor where the timing is way off. I attached a WOT DL as well. If the MAF signal is dirty how will that affect the load calculation?

I'm starting to think the load at low rpm is off. At WOT air load is pretty spot on to actual boost but down low I don't see how it can come up with a load greater than 1 with no boost and no backpressure showing on my EBC datalog. My understanding is load is a calculated value not a measured value and the torque tables can affect it. I found another area that makes me think this as well. Going 70 mph in 5th gear I slowly increased the throttle to put the car under load and I had 0.5 lbs of boost. Load however was below 1 and it didn't add any fuel but showed Lambda commanded being 1.0. My other cars that are boosted as soon as I start gradually pressing the throttle you can watch the AFR start getting richer. This is the 5th gear DL.