Btcox

Do you know of a good way to test/check those?

Alright, replaced the Ignition Control Module and still the same issue. We were driving it yesterday and it started hesitating again, so I wanted to try a few things. I thought this was interesting to note, if you put it in neutral the rpms rev normally but if you put it back in drive or any gear (automatic transmission) it starts to hesitate again. I'm wondering if it may be related to pressure in the transmission rather than an issue with the engine. Still no check engine light

I did not, my wife drives it for work and doesn't have time to stop and freeze spray it while she's working. When I drive it I can't reduplicate the issue unless I drive it for a few hours when it's hot outside. By the time she gets home it's not as hot out anymore and I just end up driving around for hours wasting gas so I ended up ordering a new one

Update: By looking at the codes, there is no code for an ignition (ignitor) control module for the impreza so this could explain no CEL. Its a pricey part but I've ordered a replacement and should arrive Thursday. I'll be back with an update after install and test.

Thanks! I'll start tinkering with that and or replace it, then be back with an update.

It's worth a shot, I would probably use a can of contact cleaner though. I'll have to try that next time it messes up

Thanks for the info! After the issue starts it does not stop until the car has cooled down. The typical quick fix is to pull over, turn off engine, and wait for it to cool down, then start up again and drive for a few minutes until it does it again. The problem does not occur at engine operating temp but is weather/heat related somehow, typically when it's over 80 degrees Fahrenheit on a hot sunny day. The hotter outside, the worse it gets, typically under a heavy load (accelerating or going up hill). No check engine light has ever come on. So, the fuel pump has been replaced already but I have not replaced the ignition module. I'm attaching a picture to make sure I'm thinking of the correct part you are talking about

Thanks! I will definitely look into that

Replaced the crankshaft position sensor, same issue. The other day my wife ran it too low on gas and experienced the same issue. I'm thinking maybe I need to replace the fuel injectors next

Alright I have replaced the PCV valve and am still having the same problem. Additionally, I swapped out the IAC and TPS with another used one I purchased from Japan. Those test fine as well. Should I start looking into an ECM or possibly the MAF sensor? I'm running out of ideas Here is a video of it acting up. Not sure if this will help or not

Have not replaced PCV valve and no to the EGR

Ordered a used throttle body assembly from the UK with TPS and IACV attached so I will try to use those when they get here but I tested both the TPS and IACV yesterday and both test good. Removed the IACV and put 12 volts to it. It operates as it should with no binding that I can tell. Might be different under extreme heat but that would be harder to test. TPS resistance moves smooth with no jumping. Again could be different under heat but hard to test. Cleaned all the grounds under the hood. Car ran good in 70 degree weather for one day, then the following day ran awful at noon when sun was out and temp was in the 80's Since I reset the ECU, I have not been able to get another code. I plugged the 2 black wires together, I think those are used for view stored codes and have not been cleared. Is there anything else I should replace or anything else I can test/check for to find the issue? Someone at her work mentioned it could be the ECU overheating but I think those are located inside the car under the glovebox which should stay cool being inside the car, so I kinda doubt that but I could be wrong

Okay, l see what you are saying. I have that and a FICD which is mounted on the intake.

I think your thinking of the device called a FICD or fast idle control device. That one adjusts the idle up when you turn the AC on

Gotcha, yeah that's a tricky one to find. Might have to just order a throttle body from UK with all the parts on it and see if that works. Or see if a US throttle body will fit and install new US parts