Flooding when cold

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Freise
Knows Some Stuff About 240's!
Posts: 452
Joined: Mon Mar 30, 2009 10:29 pm
Location: St. Charles/Cape Girardeau

Flooding when cold

Post by Freise » Fri Feb 07, 2014 1:07 pm

95 S14 Ka24de-t z32MAF Nistune S15sr440 injectors
Car has always had difficulty starting on the first try in the cold; takes a bit longer to fire up and once going runs rough and burns off a lot of extra fuel, but usually runs fine after a minute or two of idling.
I moved out to PA last summer and it's a bit colder than the midwest during winter, plus I no longer have a garage, and lately the car has been firing up, but then will die after about ten seconds of idling. On the next try, it will kick out a puff of black exhaust (i assume that the engine has flooded, however, when the engine begins to die the wideband shows lean not rich), and again, idles for about 10 seconds, then dies. After a few tries it usually manages to hold the idle and once it does so for say 30seconds to a minute it will run perfectly fine, even in 10* weather.
Now I can't even get her started up, it floods out on the first try and if it manages to maintain the idle it sputters and backfires, and is dumping fuel.
I've replaced dizzy cap, rotor, and wires with oem nissan, new plugs, have cleaned maf, voltages appear to be working correctly, tps voltage appears to be working correctly, replaced coolant temp sensor, even tried reverting my tune to stock, and now I'm out of ideas. Any help or suggestions would be appreciated.
95 240sx KA24DE-T
S15 Injectors
Z32 blow through

williemorris
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Re: Flooding when cold

Post by williemorris » Fri Feb 07, 2014 1:50 pm

Did you check the o-rings on the injectors I had a similar issue

Freise
Knows Some Stuff About 240's!
Posts: 452
Joined: Mon Mar 30, 2009 10:29 pm
Location: St. Charles/Cape Girardeau

Re: Flooding when cold

Post by Freise » Fri Feb 07, 2014 3:24 pm

Checked the o-rings, all four injectors are bone dry when priming the pump.
I got her back to starting up and idling albeit very rough, had to do so by reloading a stock S14 tune, corrected for injectors and MAF (All done through Nistune)
On top of this, I had to crank up the fuel pressure to ~56psi which is WAY over stock just to get it to idle, Wideband tells me it is idling at 13-14afr but there is still a rough popping/cracking and shaking, not smooth. I've gone through each and every fuel line with a compressor to ensure no clogs, fuel filter is good as well. Fuel pressure regulator is a tomei adjustable fpr, bought through enjuku and came with a certificate of authenticity so I'm fairly certain it should be good/reliable. It is only a year and a half old. Fuel pump is a walbro 255 replaced 3 years ago

Checked out the MAF voltage, at idle it's hovering right around 1.2V. iirc it should be around 1.4ish, but it looks like it should still be acceptable with 1.2v @ idle
95 240sx KA24DE-T
S15 Injectors
Z32 blow through

neverlift
Knows Some Stuff About 240's!
Posts: 263
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Location: fla

Re: Flooding when cold

Post by neverlift » Fri Feb 07, 2014 11:06 pm

bov recirculated?
Image

Freise
Knows Some Stuff About 240's!
Posts: 452
Joined: Mon Mar 30, 2009 10:29 pm
Location: St. Charles/Cape Girardeau

Re: Flooding when cold

Post by Freise » Sat Feb 08, 2014 2:15 pm

Think I got it figured out, turns out one of the leads to the fuse box was loose where I extended the battery/alternator wire for battery relocation. It was partially pulled out of it's ring terminal, so I think when it was cold it was contracted and making a poor connection. I've got it secured with a fresh terminal and properly soldered this time, and she fires right up. The real test will be after letting it sit and get cold, so I'll know for sure in the coming week.
95 240sx KA24DE-T
S15 Injectors
Z32 blow through

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