car sat 2 months, turns over won't idle

[s13Ks]

Hi

my car (s13 sr20det '91) was running great 2 months ago. just been sitting.

car starts and immediately dies. a few times the car has started and idled but is a bit rough, then as rpms rise it dies.

there is pressure in fuel line. no fluid leaks. no vacuum leaks. unplugged afm - no difference. unplugged o2 sensor - no difference. unplugged iacv no difference. o2 sensor heater circuit has continuity. afm has voltage (20-30mv) when car is on.

if anyone has any suggestions as to what I should try, I would appreciate it. i don't know what i'm doing.

car details:
91 sr20det red top drift beater manual trans
z32 afm, aftermarket catalyzer, tuned pfc, fuel pump, injectors, s15 turbo, exhaust mani, intercooler, oem coolant overflow tank


oxrwsukgfPQ

[brndck]

will the car stay running if you use carb spray?

when it stalls, will it fire back up?

have you drained the tank and cleaned the fuel pump sock?

[s13Ks]

will the car stay running if you use carb spray?

when it stalls, will it fire back up?

have you drained the tank and cleaned the fuel pump sock?

1. haven't tried that yet, might be able to if i can get it to idle again
2. it will start and turn over, but won't idle
3. I have not, I took out some of the gas and it looks/smells normal. been sitting with a mostly full tank, so don't expect rust. i also changed the fuel lines and fuel filter a few years ago


it has idled a few times. usually, it just does what it did at the end of the video. not sure what's making the difference. both times it died on its own.

[jedi03]

i would suggest change fuel filter again, do fluid flush, check battery condition/alternator tested...that's all i can think of atm

[s13Ks]

https://i.postimg.cc/FKvf0JwW/IMG-5472.jpg

any clues here? should O2 read 0 when the car is ON but not running?

ruled out the TPS and battery today. I took out some fuel, checked it and it looks okay. the car doesn't want to idle (except in that one video), but starts and turns over.. seems like the alternator probably isn't the issue, but is there a way to test it without the car running?

the tank is full and the car is parked in front of an apartment in the middle of the city. i can't remove all the fuel unfortunately.. someone will walk by with a cigarette.

[s13Ks]

thinking O2 sensor. can anyone confirm voltage should not be 0v with the car ON?

also, if the ECU picked a problem with the O2 sensor, would it light up the catalyzer light?


edit- seems like O2 sensor should do nothing when the car is cold.

[EnnEssEnnKAT]

Siphon out the gas and replace it with fresh gas, could have absorbed water or not lasted very long. Sucks you got a full tank but worth a shot imo. Good luck


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[fufanu180]

I don’t think that an o2 would keep the car from idling. If anything it would just make the car run pig rich if it wasn’t relieving a signal from the o2 sensor.


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[jedi03]

disconnect fuel line from filter or rail and connect hose to drain fuel into a bucket/fuel container and do until is barely spurting out...get 2 gallons of fresh fuel and try again...maybe some seafoam in the fuel too

[brndck]

will the car stay running if you use carb spray?

when it stalls, will it fire back up?

have you drained the tank and cleaned the fuel pump sock?

check the fuel sock, not the fuel filter.

and see if the car will run on carb spray.

[nick_d_240sx]

Have you tried driving it around and see if it gets better?

[s13Ks]

Car will idle sometimes, but mostly die as soon as it starts.

It will idle at 800rpm, but with a ton of gas vapor in the exhaust, my PFC is telling me injectors are at 14.4% duty at idle. Should be closer to 1%. I have 550cc injectors, been running solid on this tune for 10+ years. Engine doesn’t seems to be missing. So it seems that is what’s flooding it.

Anyone know what might cause this?

[nick_d_240sx]

You are correct idle DC should be ~1%. Are your injector settings correct on the PFC?

A quick google search shows there's an Idle Learning Procedure that may have to be redone after the battery dies for an extended amount of time but you need to backup your tune first.

Here is the zilvia thread about it. (https://zilvia.net/f/showthread.php?t=326098) See post #6.

[crazyorigin]

As mentioned it would be a good idea to pull the fuel pump/sending unit out and check the sock finter on the pumps intake. Even if the tank is clean and rust free, it could be clogged. I took the one out of my S13 and the rubber grommet that holds the pump in place at the base, and also holds the sock on partially, was pretty much liquified and had heavily contaminated the sock filter along with a lot of other debris from the tank. I know I was really glad I decided to pull the tank and clean everything before firing up the new motor I built for the car.

I doubt the gas is bad, I had my car firing up with a badly hurt engine on gas I know was at least 3 years old and basically like turpentine. Unless you got some really bad gas out of the pump I doubt that's it.

[!Zar!]

Gas wouldn't go bad in two months.

Have you ensured your PFC didn't lose its tune?

[saiga488]

Sounds like a fuel problem to me also. Could be weak or clogged pump, bad fuel, or injector issues.

[s13Ks]

the issue seems to be too much fuel. the pump, fuel filter and injectors seem good.

the exhaust has pretty intense gasoline vapor.

i'm replacing the sparkplugs next.. suspecting maybe weak spark. but not sure how that would change the injector duty.


Gas wouldn't go bad in two months.

Have you ensured your PFC didn't lose its tune?

does that happen? my other settings etc. seem intact. do you know whether there is something that could just affect the injector duty map, and how can i confirm my map hasn't gone wonky. i do not have datalogit but I have a hand controller.

[s13Ks]

uhh.. is this right?

I honestly don't remember what this is supposed to look like. Originally had it tuned by Jun in like 2008 or something probably. Is this map even being used?

i'm no expert on the power fc so i'll refrain from panic for now.


https://i.ibb.co/zNCkRQY/Screen-Shot-2019-11-13-at-10-00-39.png

https://i.ibb.co/h2RpS7k/Screen-Shot-2019-11-13-at-10-00-32.png

[S14rebuild]

Power fc isnt shown correction for injectors...... needs retune

[s13Ks]

is it possible it is not displaying the injector tune for some reason? or is this what it is

also, is this a common issue? I don't understand how this could have happened. all my other settings look fine


does anyone happen to have a mirror link to the paul r33 power fc faq? the original is down.