JS City Goblin - 2010 LS

JSATX

Goblin Guru
Yeah I can’t swap the MaP that would really make everything go crazy.

I did confirm my map was working correctly. I’m getting 15psi with engine off and about 5 at idle which is all normal.

I’m running the 1.0 tune from ZZP for a 2.2L on low boost. Confirmed they tuned it for my map. Which if they didn’t I wouldn’t be getting realistic MAP values.

I’m now getting a “too lean” code. It’s sensing something and slamming shut at low rpm.
 

JSATX

Goblin Guru
Too lean = not enough fuel. Could be pump, injectors, filter, duty cycle etc
Trying to focus on things that were changed. The tune, injectors, and MAP.

I know my fuel pressure is weird. But high is better than low I guess.

My deceleration fuel cutoff bounces all over the place at idle.

Car ran perfectly before. Just a matter of time and effort to get it back that way.
 

canyon bolieu

Well-Known Member
Tune must be off. Or did it work good then start doing the cut off? Could be going to rich then cutting fuel.

Do you have an afr gauge?
Boost reference fuel pressure system??

And HP tuners is well worth it! I have vcm pro
 

JSATX

Goblin Guru
Tune must be off. Or did it work good then start doing the cut off? Could be going to rich then cutting fuel.

Do you have an afr gauge?
Boost reference fuel pressure system??

And HP tuners is well worth it! I have vcm pro
These cars are supposed to have built in boost reference fuel pressure systems. They increase fuel pressure relative to MAP sensor output. Which is why it makes no sense that they said fuel pressure isn’t a tunable parameter.

I’m not sure if it was doing this during the first drive when I made my initial post-turbo post. I didn’t drive it long enough it was just around the block.

I’m sure HPT it’s worth it in the long run just can’t afford it right now.
 

TheNuker

Goblin Guru
These cars are supposed to have built in boost reference fuel pressure systems. They increase fuel pressure relative to MAP sensor output. Which is why it makes no sense that they said fuel pressure isn’t a tunable parameter.

I’m not sure if it was doing this during the first drive when I made my initial post-turbo post. I didn’t drive it long enough it was just around the block.

I’m sure HPT it’s worth it in the long run just can’t afford it right now.

Yeah the zzp BRFS says it allows fuel pressure regulation beyond the PCM, the way I read that is that the pcm can change the fuel pressure.
https://zzperformance.com/ecotec/boost-reference-fuel-pressure-system.html

Nuker
 

JSATX

Goblin Guru
Yeah the zzp BRFS says it allows fuel pressure regulation beyond the PCM, the way I read that is that the pcm can change the fuel pressure.
https://zzperformance.com/ecotec/boost-reference-fuel-pressure-system.html

Nuker
That’s interesting. But I have the later base model (64 bit computer after 2007) which can compensate for higher pressures. It’s the fuel pump itself that’s the limiting factor.

In that product discritption they do talk about the 60psi in tank regulator though. Hmmm
 

JSATX

Goblin Guru
HP tuners is on its way. Already spent a solid 6 hours watching tutorials so hopefully when it gets here I’ll be able to identify the problem quickly.
 

JSATX

Goblin Guru
Had another idea, just spit balling here...

The injector pulse width is calibrated for a certain fuel pressure. With my pressure so high it could be going to a very rich condition. A narrowband O2 sensor can actually sees a very rich condition as a very lean condition. At lower rpm there’s simply not enough air to burn the amount of fuel that’s getting dumped and Emergency limp mode is triggered. However when I carefully get it up over that ~3,000 rpm range there’s enough air flow to accommodate that extra fuel and it works correctly, still rich, just not rich enough to kill it.
 

JSATX

Goblin Guru
A small amount of good news. The over heating issue has been solved. Rerouted the turbo the same way that the Saab 9-3 does it instead of using the heater core plumbing and the temps are much much better. Maxing out around 185 instead of 220.

And the "too lean" code hasn't come back since the last DTC clear.
 
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JSATX

Goblin Guru
The software showed up today (thanks ZZP one day shipping!) and I can say with almost complete certainty that there is a major tune issue.

It confirms exactly what I felt. If you are under 3k rpm and give it throttle, as soon as there is positive pressure the car goes dead lean (18.5 AFR!!) spark advance goes to 50° and it shuts down.

If you are over 3k rpm and punch it I get nearly 10psi of boost and immediate, extreme acceleration at approximately 13AFR. One run I went from 12mph to 70 mph in 2.8 seconds!

So now it’s back and forth with ZZP until they get this thing straightened out
 

TheNuker

Goblin Guru
I’ll be watching for your zzp tuning feedback. It seems it’s either super positive or they make a couple changes things still don’t work great and they tell you to flip off... lol

Nuker
 

JSATX

Goblin Guru
this is the very first start before everything was even completely hooked up. I really like the sound of it.

 

JSATX

Goblin Guru
Progress report:

Its much better! ZZP found that my tune had not been setup for blow through MAF and it wasnt liking the positive pressure.

I am still having trouble when under high load, for example it still shuts down if I try and shift into 2nd too early. All of first gear is usable now.

I spun all the way through 2nd gear on a launch though. Almost ended up in a ditch.

Log shows 2.1 seconds from 9mph to 60mph! Honestly I dont know if I'll even try from stopped, Im scared I'll snap an axle!

Definitely getting there, slowly but surely.
 
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JSATX

Goblin Guru
It was rainy this weekend so I worked on small jobs that I’ve been putting off. Finished welding the intercooler bracket and painted it. Pretty happy with the way it came out.
77CB3180-7441-4851-BB07-33182525CECF.jpeg


I also wrapped the exhaust with PTP exhaust wrap. There is very little heat transfer between the exhaust pipe and intake.

And I did get it hot....
3F391728-2E5A-446B-8951-44833A555B1C.jpeg
 

JSATX

Goblin Guru
Well since getting the tuning software I have spent close to 5-6 hours a day trying to learn it. The tune is getting a little tiny bit better each day.

First gear is pretty much sorted out. Still a few issues with other gears while also in lower RPM. Over 3k is good in all gears.

Still not sure what the optimum AFR for this engine is...Once I get it street tuned I will definitely need a dyno for final tweaks. Its nuts how fast the speed limit sneaks up on you.

The factory waste gate is letting almost 14lbs of boost through...I hope I can adjust that down closer to about 8 or 9lbs.
 

JSATX

Goblin Guru
When your ready to Dyno let me know .I have Dyno Lonny used.Free to you. Dennis
That’s a really awesome offer, thank you.

I will definitely take you up on that. I still feel like I need to get it Street drivable before getting on a dyno...and at the rate I’m going that could be awhile.
 
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