Hey guys,
Im looking to see if anyone has any insight into the issue im having. I was working on my project car, 1998 civic dx, when I decided to let it idle for a while out of curiosity. After a test drive and 10-15 minutes of idling later, it starts idle surging. Starts off minimal, then increases and almost dies at the bottom end of the surge. When I tap the gas, it shudders and dies.
Any insight would be appreciated.

 

clean the IAC valve and then go from there. DO NOT MAKE ANY ADJUSTMENTS TO ANY SCREWS

 

Still haven’t got to iacv, but I’m getting a misfire code for all 4 cyclinders and p0300 and p1399. Can that lead me anywhere? It also has a hard start.

 

clean the IAC with a wire wheel, you are getting a lean misfire

 

Cleaned, coolant burped, ran better for longer but still dies and surges and is now throwing codes p0170 and p0171

 

Take the Iac off again, and post a picture of it, If its the IAC Im thinking, then either you didnt clean it good enough, or its broken/busted. The p0171 tells me that the IAC is stuck open letting too much air in.

https://honda-tech.com/forums/honda-...ic-ex-3301164/

 

Yup, sounds like a dirty IACV to me but how old is your PCV? That would be the next step after checking for vacuum hose leaks. P0170 is MAP Fuel Trim problem.
Florida Rich

 

I recently had a similar issue.
if a clean IACV doesn't work, consider the following:
1.Grounding wires ( especially if it dies at 2000 rpm's when in motion). https://www.ebay.com/itm/38404904578...Bk9SR-bo1trKZg (this takes care of the dies on revving issue)

2. Fault in the distributor- you may need a new cap or rotor or both. I recommend the VMS brand https://www.vmsracing.com/collections/distributor-caps pick the one without the external coil. (this takes care of the misfire issue)

3. Engine coolant temperature SWITCH (not the sensor) - you'll have to drain the coolant to this. If you have a scan tool that logs data, look for the ECT entry- should read outside temperature when cold. ( takes care of residual hunting idle.) You'll need a 24mm deepsocket to get to it.

 

Thanks for the help, but unfortunately my block has some damage. Im going to go another route