Hey guys,

Ever since I've been supercharged at 7psi, every once in a while (like once every 3-4 weeks) the car would start to jerk and hesitate when I would start from a light. To fix it, I would just push in the clutch, wait a second, and start again.

I recently just got back from the tuner; I'm now at 12psi on a greddy EMU. The car pulls great but I swear every time the temperature changes 5 degrees the car starts going crazy every time I start from a standstill. It gets better as the day goes on. My wideband shows the car going crazy lean.

Now, I've done some research and lots of people seem to be pointing at the map sensor. Just for safe keeping I used a zip tie to hold it together and it seemed to fix it completely for the rest of the day. Now today it's about 10-12 degrees cooler and we're back to the way it was before.

Any thoughts?

-Nate

 

either the tuner sucks or you need a better management

could be both.

but if its running crazy lean then you 100% need a better tuner, even if your map sensor sucks...he should detect that while he's tuning the car.

 

Well, the thing is, after the map sensor adjusts it runs just fine. Like I said before it did it every so often when I was running the base vortech kit and FMU. Now it's just much more often.

When I picked up the car on Friday, it was 66 degrees and hesitated a couple times on the way home. When I drove it again that evening, it was just fine. Saturday it was 78 and ran perfect all day. Today it was 65 and hesitated 3-4 times on my way to get food, but only hesitated once when I was leaving the restaurant. The rest of the drive was fine.

I really think it's an issue with the map sensor, but who knows. I'm also going to check my filter and throttle body to make sure they're clean

 

go back to the tuner and tell him about this issue

 

I am no expert on this matter... but i am running 12.5 psi on a vortech supercharger on a fully stock motor. no headgasket etc,etc. i took my car to inline pro to be tuned and i origanaly had the emanage ultimate to go with the 12.5lb pulley but they said that was bad ju ju. so i bought the AEM EMS and the car runs beutiful. no problems at all. just thought i would put in my 2 cents

 

Most tuners in my area don't like to tune Greddy EMU's, not because they're bad tuners, but because they know how difficult it is to tune a piggyback system against a stubborn ECU like ours.

Yeah, in a WOT situation, the car runs beautifully, but when in cruising speeds, the 2 system end up fighting each other instead of working together, so it take a lot more time to get it tuned properly compare to a standalone system.

But I have seen a couple success stories on this site, try a search and PM the folks that had good luck with it, and see what they had to go through to get it working properly. Good luck!

 

I've definitely been searching and I'll probably start taking your advice and PM'ing those who got their car running smoothly.


I appreciate the advice guys!

Nate

 

Same set up but with stock pulley, AEM EMS, runs great. Even when it is 15 degrees outside.