Nissan 370Z Forum - UpRev ECU tune results for Semtex's Z

Nissan 370Z Forum (http://www.the370z.com/)

- Tuning (http://www.the370z.com/tuning/)

- - UpRev ECU tune results for Semtex's Z (http://www.the370z.com/tuning/10654-uprev-ecu-tune-results-semtexs-z.html)

Forrest that was so hard to read man, but that does sound a little weird, I wonder if its the same thing they are talking about.

Yes, I did postpone my tune until you guys get this figured out.

Quote:

Originally Posted by semtex (Post 259359)

Okay folks, all is not well. Two things are going on.

First, since getting the tune done, my car is doing something rather strange on cold starts. I start the car, wait my normal 30 seconds for everything to warm up, and when I slip it into 1st and tip the throttle in, there's like this weird dead spot. Gas pedal goes down a little, I start to feather the clutch in (same thing I've done a million times before), and nothing. The rpms just kinda don't go up, then all of a sudden, WHAM, the rpms jump up to where they ought to be and I go lurching forward like I've never driven stick before. But it only happens on cold starts, and goes away as soon as the car has warmed up a little more. Like by the time I get out of my neighborhood and make it to the first set of lights a half-mile from my subdivision, the problem is gone. I can launch as smoothly as always. No dead spot, no lag effect.

The first time this happened was yesterday morning when I left to go to the gym. I thought maybe it was my imagination or maybe it was human error on my part. But this morning, it did the same thing. It even did it when I was done with my workout and left the gym to come back home (car sat for about 2 hours). Something is f'd up. The driveability of my car has been compromised.

Okay, the second thing going on is this. I just got back from my DynoJet pulls. I have LOST approx. 15whp since my last DynoJet pull on the same DynoJet! Check it out. RunFiles 003 and 005 below are from today. RunFile 010 is from back in May.

http://i618.photobucket.com/albums/t...Jet_103009.jpg

I know, I know . . . different pulls on different days, months apart, right? But look at the run conditions:

http://i618.photobucket.com/albums/t...t_103009_b.jpg

The green and yellow lines are from today. The blue one is from May. It was cooler today than it was in May. Humidity is higher today than in May, but the correction factors should compensate for that.

Take these two things together -- the weird dead spot on cold start, plus the bizarre dyno results, and I think I'm being fair in saying that something ain't right!

I haven't been able to talk to Sharif yet, so I'm not sure what the next steps are. But right now, I'm about ready to have him flash my stock tune back in. This is not the desired result.

Ok well I haven't done a dyno pull on my original dyno but the same exact thing is happening with me as far as cold start drivability. I just had my done by uprev on Thurs. And I'm in Dallas right now and haven't contacted rich cause it's the weekend but I will be. Didn't drive my car again till last night and it did that along with this morning. A little upset but hopefully UpRev will make things right. I'm really curious about that horsepower loss, I have the opportunity to re-dyno my car on my original car possibly Monday but we'll see, might not have the funds.

Quote:

Originally Posted by B1nks (Post 260655)

We all know that Uprev will take care of the cold issue. But on Semtex's #10 dynojet run what the graph does at 4150rpm is kind of strange.

Had my car dyno tuned with Uprev on Thursday and have a similar problem. With a cold engine, when you push the gas pedal there is very little response then all of a sudden it just takes off. Operates normally after a few minutes.

Quote:

Originally Posted by Forrest (Post 260468)

Hope this helps you with the "cold starts" and having a tune.

I have no tune and zero mods.

Every now and again i start my car like normal and the mother beep LURCHES foward. Then with out the foot off the gas, the car starts racing foward like im pushing down hard so i have to shift it to second to get it to stop doing that.

Then a new thing happened, i lurched foward and started to race, then it totaly stops like it stop recieving gas, then apply alot of gas again jerk me foward, then stop applying gas and let it slow down, apply alot of gas and lurch me foward again. All while my foot was off the gas, clutch and break. If any of you was to watch me from outside the car it would look like a novice is just learning the clutch and pushing it in and out while foot on the gas.

This does not happen all the time, but i know to let the car sit for like 3-5 minutes before driving.

Hope this info helps those who are fearful the tune is causing the problem.

ps at like 33 degree's c, the z feels monsterously powerful.

What you're describing is NOT what is happening with my car. And what my car is doing started the morning after the tune. But we'll get to the bottom of it soon enough. What you're describing sounds kinda scary, to be honest.

After the tune on Wednesday at UpRev I noticed the same thing I have the AT but you push the throttle and it almost seems like your in neutral the the gear grabs and it takes off. Also the Vallet mode did not work they said they would work on a fix for it Theft mode did not seem to work either.

Holy moly. Premature product release, anyone?

Quote:

Originally Posted by semtex (Post 261275)

Holy moly. Premature product release, anyone?

Hey Semtex....mine is doing the same. Exactly as you described. Hmmm...when I talked to Sharif at the time I got my tune last week, he indicated the "bugs" were worked out. I think UpRev didn't catch this before releasing. I'm gonna talk to Sharif and see what his thoughts are.

Quote:

Originally Posted by myfirstz (Post 261278)

Thx Niko. It just so happened that I was on the phone talking to Sharif about this when I looked at your post, so I let him know that your car is doing this as well.

They're comin' out of the woodwork folks....hopefully it's something simple

Just run in stock tune folks till you get a updated map to fix your tunes from Jared.

and how are we supposed to do this ?^^ Don't even know if the extra option tunes that come with it work and since the valet and theft mode don't there is a doubt the others do too.. :-/

Quote:

Originally Posted by NIZMOZ (Post 261590)

Just run in stock tune folks till you get a updated map to fix your tunes from Jared.

I asked Sharif about this and he said it won't fix anything. What he explained to me is that, from the sounds of things, the issue is with the UpRev ROM, not any particular tune/map per se (which is why so many people are experiencing the same issue). When you get your car tuned, the first thing that happens is that they flash in the UpRev ROM over your car's stock ROM. All the maps are contained within that ROM. In other words, you don't switch between ROMs. You switch between maps within the ROM. So even if we switch to an alternate stock map, if the issue is within the ROM itself as Sharif suspects, the problem will still be there. Or to put it another way, the stock map is still an UpRev stock map, not the one that came with your car. The only thing we can do, per Sharif, is wait for UpRev to fix the bug.

Not really, you can take the map completely off and revert back to stock.

Quote:

Originally Posted by RCZ (Post 262320)

Not really, you can take the map completely off and revert back to stock.

You're assuming he made a backup of my stock ROM. He didn't. He said it would have taken an hour to do that via a ROM dump.