Hey guys, so I picked up a mk3 turbo targa top about a month ago with a built engine (eagle rods, cp pistons ported polished head, id1000 injectors, gt3582r, aem ems). I just replaced the chsa of the turbo and now it idles very lean at 3,000 rpm with 16ish AFR's. Originally I thought it was the wideband o2 sensor so I replaced that just yesterday. And yet the problem persists. I noticed the map sensor input is received at 0.83 volts and only goes up to .85 volts under throttle and doesn't build boost. I am going to pick up a new aem 3.5 bar map sensor tomorrow to test it. But any ideas before I proceed?
map sensor issues?
- Thread starter JSLICE
- Start date
Also, the input is at 1.5 volts before I start the car. Engine load is consistently around -11.5 even with throttle.
Map sensor signal voltage should vary depending on how much vac and boost from less than a volt to almost 5v when maxed. If yours is not then it is bad.
But also make sure the vac source and line are good.
But also make sure the vac source and line are good.
Well I called the previous owner and said he had big idle issues before because the tps sensor had a lose wire. So I messed with the connector a bit and recalibrated the sensor through aem and so it seems to idle fine now. But the engine load still seems all messed up, it stays around -11 psi engine load and thus leans it out and doesn't build any boost really.
I hope he would have told you the "big issues" before he sold you the car. This is why I prefer to get an unmodified car to start with. Sometimes you get what they cannot fix.
16 ish AFR is not far from 14.7 AFR. Is the ecu set up for o2 sensor input. I heard some tuners don't use 02 feedback after tuning? My car runs 14.3 to 15.4 constantly sweeping back and forth with the average being about 14.7 at a steady state cruise. Factory ecu with VPC GCC set up. My wide band shows me the factory 02 sensor is working properly.
16 ish AFR is not far from 14.7 AFR. Is the ecu set up for o2 sensor input. I heard some tuners don't use 02 feedback after tuning? My car runs 14.3 to 15.4 constantly sweeping back and forth with the average being about 14.7 at a steady state cruise. Factory ecu with VPC GCC set up. My wide band shows me the factory 02 sensor is working properly.
I was thinking of maybe trying to use the map sensor as a throttle input? And 16 afrs is really rough idle because usually my idle is around 13.5 afr with the injectors pulse rate really low
I downloaded the EMS log files if anyone wants to take a look and I also noticed that the ignition timing in around 35 but when I change the ignition map, the idle drop is substantial