So I have covered this issue a few times.
The car is running an SR20VE and there is a AEM FIC8 controlling the fuelling and timing.
There has been an ongoing issue with regards to inconsistent power and stalling at idle.
I cleaned the MAF a few months back and that seemed to sort the problem but after a few weeks it came back.
So I decided to check the signals coming from the TPS and the MAF sensor with a multimeter.
All okay, with ignition on and engine off.
With the engine on it was a completely different story.
Voltage signal from MAF and TPS would drop sporadically.
I do not use either of these channels to tune the FIC so I disconnected the TPS first and immediately the TPS signal became rock solid.
I disconnected the MAF from the FIC and the same result. Rock solid signal with steady idle.
It has only been a day since I disconnected the TPS and MAF so it could just be a fluke that all is okay now but I have a feeling it will be okay.
This is a major bonus. Feels like a new car now. After months driving not knowing how much power I am going to have for each journey to having a completely normal engine is a huge relief. Fingers crossed.
Was the problem down to the FIC?
It is possible. I have heard other people having idling issues with the units but I am not so sure this was the case with me.
The FIC8 has 2 ground wires. I connected them together to the one ground on the ECU. It is possible I should have grounded these wires separately.
At the time it was easier just to disconnect the MAF and the TPS but when I have time I will see if separating the ground wires does anything.
One issue with the FIC that is a real pain is the datalogging. The sample rate is 100 hz which is completely unneccessary not mention the analysis software is pitiful.
I would use the Innovate Motorsport wideband for the datalogging but the problem is the FIC does not have a 5 volt output for the MAP sensor. A datalog of lambda without the MAP is pointless given the fuel is adjusted according to MAP pressure.
Ah well. For the moment I am just relieved the car is running properly again.
Could be a problem connected to the FIC but the Walbro GSS342 pump seems to be sucking the pick up dry when fuel levels are low.
I’ll see if disconnecting the TPS and MAF solves the low fuel problem and let you know.
Rust is the biggest issue on the car at the moment. The wheels arches are going on all 4 sides. I am going to start looking for a clean car to transfer the motor and suspension into and the car has many bodywork problems. Too much to be worth fixing that is for sure. Shame as the engine, chassis and brakes are still top drawer, touch wood.
While I was troubleshooting the signal issue we did some full throttle pulls. It seems an AFR of around 13.1 is the best for power on the SR20VE. In case you are tuning on the road, this could be helpful.
The car has over 200,000 miles now and the drivers seat looks all of those miles. It is still comfortable but something will have to be done. I don’t mind spending the money on a seat because I can take it to the next car.
Saying that, pretty much everything can be taken to the next car except bodykits. Lucky I am not interested in bodykits!
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