Tuner F'ed Up..Big time. What do I do?
 

Well hello guys... title could be an exaggeration but... I found a slight problem..

Curious what you guys would do in my shoes....

When I went to my tuner on the day of my tune about 2 weeks ago. He asked me what the FSM said to set for fuel pressure. I checked the FSM and it was 51. He changed it to 51... and then he continued to tune.

Today I wanted to check what the Fuel Pressure was. I then proceeded to take off the vaccum hose on the fuel pressure regulator and discovered it was not even on... being held on by literally 1 thread and it was leaking air. I took it off, changed the FP to 50 (it was slightly higher maybe around 58) and tightened it...

Now, @ boost, I am running 13.5+ AFR... should I just crank it back up? :|

I think he tuned it with the vaccum hose loose.. :icon22:

ok, i think it's time to take it down to sam at gtm. Make like a 5 day trip to get everything sorted out (if he is willing to work on the car since it has had quite a few issues thus far) Good luck in the build since it is the same setup that I am running, and you are a local member. If everything works out down at worldone performance with me, they will be farmiliar with the build, and can help diagnose things for you, and get it sorted out.

Well theres nothing to diagnose with the car really it WAS running great.. seems like I just need another tune.

+ I dont have them time to take it down to GTM at the moment. Believe me I would love to.

with that afr, you should not be driving your car until the issue was sorted out. get it back to your installer and get it sorted out asap. this isnt the type of car i feel like you can start playing with fuel pressures on your own. unless you are a mechanic yourself. my .02

if you have big enough injectors, you can tune the car without a vacuum line going to it. i know MANY MANY pro tuners that will not tune a car with a vacuum line to the FPR. what injectors and what boost level are you running??

i am pretty sure he hasnt messed up but did a trick to keep the fuel pressure exactly the same.

you just dropped your base fuel pressure by about 15%.....it's gonna be lean by doing that.

58/51= 1.13726 take square root =1.066 or 6.6% more fuel flow with 58 vs 51

if it was tuned at 58 i would run it at 58

yes +1 and if it is an install problem, i mean jsut take it back to the tuner, sounds like a "simple" fix possible retune really no need to bring it 100000miles across to gtm jsut for that :rolleyes:

After seeing about 10 of your problem threads....it really is time for some experienced help. I am being serious...not joking. I just hope the next thread isnt...help!....my engine blew up!! Get that car over to someone that knows what they are doing, so they can fix any issues, and put a nice safe tune on that thing. :) Best of luck...GTM is not too far from you! Make a road trip!

With an FPR, the vaccum line should be attached whilst tuning. Otherwise, your 51psi of fuel pressure, is actually 41psi of fuel pressure, when it's pushing against 10psi of boost pressure. This is basic science...the engine is one big air pump, and you have to understand how pressure differentials work across all of the working surfaces, or you will be chasing your tail with tuning.

One thing that is odd, is that you are leaning out when you attached the line. That makes no sense. If he tuned the car without the vaccum reference, then when you apply the reference, your engine should richen significantly.

I'm curious as to why you are taking the square root? I must be missing something. 58 psi is 13.7% more pressure than 51 psi...... :confused:

seriously, just take the car to some seasoned pro's like GTM and get it done right the first time, or in your case, the second.

Take it back to the tuner? The one that couldn't figure out how to use the HKS EVC? :icon17: :icon17: :icon17: I'd rather schlep it across country (which is the not case here) to a proven tuner/installer then take it back to someone that doesn't know WTF they are doing. I didn't learn that lesson until my local tuner blew up my stock motor on the dyno right after my TT install.

Yep that tuner lol... I am running 650cc injectors at 7Ib.

tick tock, tick tock goes your engine.

seriously though people, haven't any of you figured out yet this guy will not be happy until he destroys his own car?

He has been told how many times to take it somewhere to have HIS install checked out and to have a PROFESSIONAL tune his car (not his friend and his lap top).

sorry to be blunt man, but you are either really cheap (which means you shouldn't be playing with FI) or you have ADD

In the shop's defense the new EVC, not sure about the older one, needs a detailed setup process which if not done or done properly wont work, then the instructions are not the best, I had to get a cheat sheet from HKS with a simplified procedure which once I saw I realized it was simple but if you go by the original instructions you may not get it set up properly.

That is the formula for calculating fuel flow differences. The square root of new fp over the old fp.

Jining, you said it was at 58 constant for the tune, and you set it to 50ish when you put the vacuum line back on. Assuming it is a 1:1 regulator, and you are running 8 or more psi of boost than it should be the same or even slightly richer - not leaner. At idle it should be running leaner though now with the reduced base FP and vacuum reference.

Something doesn't add up.

Understandable, but at least your shop took the time to get easier directions from HKS in order to figure it out and get it working.:thumbup2: I don't know what is worse, whether jining's tuner didn't know what he was doing or whether he didn't take the extra step to get it working.:icon22:

Good point, I am picky about knowing how things work and if they don't then trying to find out why, there is always an answer.

So if you remove the vacuum line from the FPR, fuel pressure will drop during boost and you will run leaner right? Ok, I've got this crazy idea...I'm running pretty rich at WOT with the Unichip, if I remove that vacuum line, that will lean out my A/F? How much of an increase in A/F would that cause?

Yea, I know...stupid azz idea, but I'm curious.