What’s up everyone! Apologize ahead of time for what’s gonna be a somewhat long post but I’ve ran out of options

2002 S2000 full bolt on (minus header) and tuned on a LINK G4X by Evans tuning. The tune seems great aside from a major hesitation and bucking im getting at low speed (under 10 mph) and only when the car is up to temperature. Pretty much after about 30 mins of driving, if I’m crawling around a parking lot or inching up in traffic, the AFR will go super rich (like 9-10) and the car will buck all around until you give it more throttle. The AFR will then lean out and the car will drive normal.

I had a friend helping through email looking at logs and he seems to believe there is an issue with the AEM wideband and gauge I have installed. The connection between the wideband/gauge and ECU is probably not good which is throwing off my readings at low rpm.

I reached out to Jeff Evans about the issue and he couldn’t narrow it down either.

I have two options at this point. Option 1 is get rid of all the AEM stuff and install a LINK wideband with CAN gauge. Option 2 is throw the stock ECU back in the car and forget all this tuning shit lol.

For now, I have gone option 1 and purchased the LINK wideband and CAN gauge. However, what I have noticed is the wiring isnt long enough to reach from the wideband into the car to plug into the ECU. I probably need the CAN 2 meter long extension which I’ll buy.

the problem is, no one in central Florida that I can find tunes on LINK or can help install this stuff if I run into an issue. Last thing I want is to be mid installing this stuff and run into an issue and can’t get my car back together to drive it.

Everyone says LINK is the best ECU to have which is all good but it means nothing if I can’t find any professionals in my area to work on it

Any help is appreciated

 

I just got my 05 NA with link G4X tuned by evans also and I have the same exact issue although it’s not always happening. I have AEM X series wideband that I wired through CAN 1. I sometimes give it a little more gas taking off so it doesn’t bog and bounce around.

im currently having another issue that neither I, or evans, or the guy from LINK can figure out. The car cranks and doesn’t start I have fuel and spark. my trigger 2 (cam sensor) only gives 0.20 volts instead of 5 during cranking in the trigger scope test. And I can’t figure out why it but hopefully soon I will post a thread about it.

 

I also have an 05 with a link G4X and the link wideband tuned by Jeff and I have two consistent issues. The hesitation and jerking you described when at temp and starting slow when cold and so fast it sometimes stalls when hot.

These are kind of old posts, has anyone found a solution?

 

I was speaking to some friends that run this setup and a experienced installed stated to me that the LINK G4 setup - preferentially likes LINK Wideband O2's. I am not sure if that will help but maybe it is worth a shot if anyone wants to be a guinea pig...

 

I too have the same problem. Also on Link G4X. Also with AEM Uego via CAN. Also tuned by Jeff Evans. BUT, I had this same issue on the stock ecu. It is exactly as you have described. Low RPM, around 10mph and happens when the car is warmed up.
I have had my injectors cleaned, changed TPS, Changed MAP, Changed Cam position sensor and i ran an ohm test on crank sensor. Nothing has fixed it.

 

I'm also having this exact issue, it always happens after driving for a while and then hitting some stop and go traffic.
Self-tuned in open loop, it's not a closed loop fuel correction.
​​I had my injectors tested and cleaned, and fresh spark plugs and coil packs. No dice.

 

i need to do a state inspection, so ima swap in my stock ecu and O2 and will see if can get it to do it. will report back.

 

Sweet, please do
I ran the stock ECU up until the Link went in and have never had it happen with the stock one myself
Also, I do have the Link CAN wideband, but I'm still in open loop so it is not applying corrections.
It'll just randomly go super rich at low speed after driving for a bit and then sputter/jerk at low throttle exactly as the OP explained.

 

I havent had time to swap ecu yet, but i did call Link and speak with them. They said we can send an email with our map and datalog and they can investigate the issue.

 

Man I forgot I made this thread lol.

funny to see several others with the same setup, same tuner, and same issues!

I know plenty of people tuned on AEM ECU’s that don’t have these issues. I feel like it’s a problem with LINK which sucks since I do like the power the car has gotten since being tuned. The drivability issues are frustrating though and making me want to go back to stock ECU.

i read a post here that said LINK ECU likes to use the LINK wideband which I can see. I have purchased everything I need to connect a LINK wideband but my initial issue still remains…there is no one around me that messes with LINK that can run me through how to install the wideband and gauge. It isn’t as intuitive as you would think.

the AEM gauge is literally connect to ecu, ground, and go. The LINK wideband has like a sensor that you need to hook up somewhere and the wires don’t seem to be long enough to reach inside of the car so it’s confusing unless you already know what you’re doing.

probably will end up throwing the stock ecu in unfortunately and selling all this LINK stuff