2G Engine stalling constantly

[Kvkenamond]

Over the past couple weeks my car has been idling weirdly but now whenever I shift into neutral to stop, the rpm drops super low and it stalls. At the start of a drive it catches it but not super well and it gets worse and worse till it's stalling at almost every stop. I can prevent it from happening by "catching" it before it dips too low by blipping the throttle to ease it down, but even from 2000rpm it just can't keep it from dropping too low. I thought it could be the ISC and I found a non OEM one for a decent price which didn't seem to fix the issue. I thought buying a non OEM one might be a problem but I wanted to give it a shot before throwing $400+ at an OEM one.

If this sounds like it's still an ISC problem, I'll get the OEM one and try that, but if it could be anything else please let me know.

Thank you for your time!
- Kyle

 

[idkiliketurbos]

Your best bet to start with would be a boost leak test. These cars use a mass airflow sensor and any unmetered air will throw things off and cause all sorts of issues. Check for any sort of vacuum lines that are cracked or disconnected along with the intercooler piping. Also, are there any CEL's?

 

[Diamond Star Werks]

$5 meter from harbour freight will tell you if the original isc is bad. Other issues could be from the TPS out of adjustment or faulty not tripping the idle switch.

 

[dwb]

Stock MAF? If so, are you recirculating the BOV? How about your CC breather, is it routed back to the intake? Any open vacuum ports/lines on the intake snorkle where it could be pulling unmetered air?

 

[Kvkenamond]

Your best bet to start with would be a boost leak test. These cars use a mass airflow sensor and any unmetered air will throw things off and cause all sorts of issues. Check for any sort of vacuum lines that are cracked or disconnected along with the intercooler piping. Also, are there any CEL's?

I recently moved and don't have a compressor atm but I do have my homemade boost leak test attatchment. I tested it before I moved and have a large leak that I could hear around the back of the throttle body/intake. I replaced the gasket between the two but it didn't do much to help. I just removed my throttle body and attached intake piping (they're RTV'd together) and the gasket looks fine and so do both surfaces. I don't see any loose or missing lines but I know something on the back of the intake around the throttle body is leaking. Also I got a CEL for P0170 (Fuel Trim (Bank 1)), P0325 (the knock sensor goes off once in a blue moon so I'm not worried about it), and P0125 (Insufficient coolant temp for closed loop fuel control).

Stock MAF? If so, are you recirculating the BOV? How about your CC breather, is it routed back to the intake? Any open vacuum ports/lines on the intake snorkle where it could be pulling unmetered air?

MAF is stock, BOV is recirculation, CC breather is routed to the intake, and I'm not seeing any cracked or disconnected lines. I do have a pretty bad boost leak somewhere around the back of the throttle body that I go into detail in another response on the thread. I had this leak for much longer than this idle problem so it may be related but might not be the root cause.

 

[idkiliketurbos]

I recently moved and don't have a compressor atm but I do have my homemade boost leak test attatchment. I tested it before I moved and have a large leak that I could hear around the back of the throttle body/intake. I replaced the gasket between the two but it didn't do much to help. I just removed my throttle body and attached intake piping (they're RTV'd together) and the gasket looks fine and so do both surfaces. I don't see any loose or missing lines but I know something on the back of the intake around the throttle body is leaking. Also I got a CEL for P0170 (Fuel Trim (Bank 1)), P0325 (the knock sensor goes off once in a blue moon so I'm not worried about it), and P0125 (Insufficient coolant temp for closed loop fuel control).

It sounds like these codes may have something to do with the reason your car is running poorly. It sounds like you may have a primary o2 sensor failure as well as a coolant temp sensor failure. Both of these are pretty crucial to the car running properly. The coolant temp sensor code would be the one for the ECU, not the gauge. Fix those as well as the boost leaks as that is likely where your issues lie.

 

[pauleyman]

Over the past couple weeks my car has been idling weirdly but now whenever I shift into neutral to stop, the rpm drops super low and it stalls. At the start of a drive it catches it but not super well and it gets worse and worse till it's stalling at almost every stop. I can prevent it from happening by "catching" it before it dips too low by blipping the throttle to ease it down, but even from 2000rpm it just can't keep it from dropping too low. I thought it could be the ISC and I found a non OEM one for a decent price which didn't seem to fix the issue. I thought buying a non OEM one might be a problem but I wanted to give it a shot before throwing $400+ at an OEM one.

If this sounds like it's still an ISC problem, I'll get the OEM one and try that, but if it could be anything else please let me know.

Thank you for your time!
- Kyle

Don't throw parts at it. Diagnose the problem. What have you checked? Have you set idle correctly? Did something change? Have you checked ecu? Any recent work?

Never try and diagnose a car with known problems. Fix the problems first. In your case it's very likely what you described is your problem particularly the coolant temp and the leak.