Engine Dies after I let go of gas

[r6_240sx]

Happens randomly when I drop it in neutral and coast it to a stop or when I rev it and completely let go of the gas. Doesn't happen all the time though and doesn't happen at all when I have A/C on. However when I have the A/C on at idle and I turn it off there have been a couple times when it stalls.

So far I've checked the IACV, TPS, MAFs, and vacuum lines per FSM specs and they all pass. I'm thinking its fuel related either being the Fuel Filter, Fuel Injectors, or Fuel Pump.

I managed to grab a vid of it. Just want to know what you guys think it might be.

guosK7JIULU
Check engine light is on because I was testing the MAFs, haven't reset the ECU yet.

16obuCGY_Jc
Here's when I turned on engine again after previous video. I tried to replicate it, but couldn't get it to die.

[cotbu]

mafs!!!!! Are you purposely revving it to 2500rpm? Mafs (means the sensor, wiring or the ecu) and the tack is always a little off
Clear your codes and do it all again! The videos

[r6_240sx]

No real reason why I chose that RPM, I can go higher with no problem.

I used the MAFs cleaner to clean out the MAFs and checked the voltage on the FSM specs (see below) and they all pass.
http://desmond.imageshack.us/Himg706/scaled.php?server=706&filename=capturett.jpg&res=medium.

I also checked the continuity between the ECM and the harness and it's also good.

I guess I'll reset the ECM and try one more time.

[cotbu]

if you can rev higher, try to hold it there. lets say 4500rpm it shouldn't spike then drop to 2500rpm. If it passes it's definitively not the mafs, and I apologize.

[KiLLeR2001]

What engine? This can happen if you have an atmospheric BOV with an ECU tuned for recirculation. If you have a lightweight flywheel this could also play a factor.

[r6_240sx]

Sorry forgot to mention that. Bone stock KA24DE. Flywheel also stock.

[KiLLeR2001]

I would check fuel pressure. Stock FPR or aftermarket? Do you have a gauge at all?

edit: Also, check to see if your plugs smell like fuel.

[bftII40]

Take KA out replace with an SR. problem fixed. hah. i make no centz.

[h2v7]

idler breather thingy

[r6_240sx]

I would check fuel pressure. Stock FPR or aftermarket? Do you have a gauge at all?

edit: Also, check to see if your plugs smell like fuel.Car is bone stock, and no gauge. Will have to tap into line above fuel filter when I check all the fuel components.

idler breather thingy
Breather port from valve cover goes directly to intake. Ironically your post lead up to a chain of events that probably came up with the best solution. The threads I ran across were these two:
http://zilvia.net/f/tech-talk/96967-fix-your-stumbling-idle-your-ka.html
1989-1994 240sx: Stalling at stop light tutorial : Nissan Online Mechanic (http://forums.nicoclub.com/1989-1994-240sx-stalling-at-stop-light-tutorial-t254278.html)

Went and grab some intake cleaner and ran it through the IACV. Currently running fine, but I'll see tmrw because it does happen randomly. Although I did check the IACV using multimeter, would make sense why I got a false positive since it would only malfunction when the car is stalling.

[sl87]

I am having the same problem right now. Im not running a MAF sensor though, im running a MAP sensor. Was it your IACV?? I sprayed mine with carb cleaner, but i didnt take it apart to clean it. Is that what you did?

[r6_240sx]

I am having the same problem right now. Im not running a MAF sensor though, im running a MAP sensor. Was it your IACV?? I sprayed mine with carb cleaner, but i didnt take it apart to clean it. Is that what you did?I turned it on today and it ran like sh*t at idle. I'm guessing I didn't burn off all the intake cleaner because I can smell it. I haven't ran it long enough to be sure so I can't say exactly what it is.

To answer your other question, yes. There's no way in hell I'm gonna go through the trouble taking the IACV apart if I don't know for sure it's bad. Carb cleaner and intake cleaner are two different things, everyone says specifically to use intake cleaner. So you might have yourself a problem there...

[curbhuggerrps13]

did u pull the code? even though u said it was for testing mafs there might be something else.

[keytops]

If its not MAF or IACV Try this: go for a drive and once the car is warmed up drive in second gear and let off the gas, let the car roll at idle speed for about 10 seconds. Now do your rev up test again. If it doesn't die anymore its because you drive before the car is warmed up and the ecu didn't properly learn how to idle the car warm. You o2 sensor could be bad too

[curbhuggerrps13]

the one closest to the egr should be checked out. its the last one to do the whole full cycle thing for the ecu

[KOME]

Hey i have this exact same problem. Mine would die if turned on the A/C and let go the gas though. I adjusted the throttle as a temporarily fix, just assuming it's the fuel pump.

[KOME]

Also, at random times when driving, do you ever get the smell of fuel from inside the car?

[r6_240sx]

Hey i have this exact same problem. Mine would die if turned on the A/C and let go the gas though. I adjusted the throttle as a temporarily fix, just assuming it's the fuel pump.

Also, at random times when driving, do you ever get the smell of fuel from inside the car?Yeah smelled fuel when it would start stalling, that's why I thought it was fuel related.

I ran my car today, still ran like sh*t when it first started. Shouldn't of used the whole intake cleaner... Well anyway left it on for a good 20 minutes till it started idling normally. Drove it around for awhile ran fine. Let it cool down, ran it again couple hours later and all was good.

I'm gonna go on a hunch here and say it was the IACV and a $4 can of intake cleaner was the fix lol. If it stalls again, I'll bump this thread back up.

Thanks for all the help guys.