Jump to content

Very lean idle, stalling and more


Coolbeans007

Recommended Posts

Ok first things first, I am no engine tuner, I recently got my ecu with a new harness for my 4age 16v. After getting the guy who made it to tune it, life was good. After doing a few tweaks like connecting the brake booster to my vacuum manifold the idle just dropped, it went from 1200 to 500 and would stall on cold start. I disconnected it and plugged it but the problem remained. I called up the guy who made and we tweaked it a little. At the time I didnt have a wideband so we couldnt see the afr. Now I have the AEM x series gauge. Its pretty good, except, it flat out doesnt send the correct lambda signal to my ecu. The gauge is correct but the ecu reads 1.227 at idle, all the time, even when reving which sometimes stalls it. It sometimes tries to work and it will go down. For example when the car is not on, the lambda read the same on the gauge and on the ecu. The gauge's lambda is very lean on idle, it usually is in the high like 1.6. I am running on pump gas. When I rev up and it doesnt stall the lamda on the ecu is bouncing all over the place. Ive checked my connections for the analog output of the gauge and all the wires are correct. The only thing I can thing of is I made a extension to the power for the gauge and I didnt ground it to the battery. I am running itbs with cop aswell. 

Link to comment
Share on other sites

The Xseries gauges have a CAN bus output (labelled AEMNet), I would suggest you connect it to the ECU via CAN rather than mess around chasing analog ground offsets etc.  There is a set up guide for the xseries CAN bus in the help file under device specific CAN.

Link to comment
Share on other sites

On 3/20/2020 at 12:16 AM, Coolbeans007 said:

Ok first things first, I am no engine tuner, I recently got my ecu with a new harness for my 4age 16v. After getting the guy who made it to tune it, life was good. After doing a few tweaks like connecting the brake booster to my vacuum manifold the idle just dropped, it went from 1200 to 500 and would stall on cold start. I disconnected it and plugged it but the problem remained. I called up the guy who made and we tweaked it a little. At the time I didnt have a wideband so we couldnt see the afr. Now I have the AEM x series gauge. Its pretty good, except, it flat out doesnt send the correct lambda signal to my ecu. The gauge is correct but the ecu reads 1.227 at idle, all the time, even when reving which sometimes stalls it. It sometimes tries to work and it will go down. For example when the car is not on, the lambda read the same on the gauge and on the ecu. The gauge's lambda is very lean on idle, it usually is in the high like 1.6. I am running on pump gas. When I rev up and it doesnt stall the lamda on the ecu is bouncing all over the place. Ive checked my connections for the analog output of the gauge and all the wires are correct. The only thing I can thing of is I made a extension to the power for the gauge and I didnt ground it to the battery. I am running itbs with cop aswell. 

When you wire the an+ to the ecu, did you wire the an- (brown cable on the AEM X Series) to ground?

Link to comment
Share on other sites

On 3/22/2020 at 1:38 PM, Coolbeans007 said:

Nope I wired it to the other brown wire in my harness.

and that brown wire of your harness is what?

If you don't have ground on that brown wire the voltages that send through the 0-5v signal its going to be off. Probably thats why your ecu is reading odd.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...