it runs fine when its cold. loses power when it warms up. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

punkblackS14 · 03-24-2003, 04:58 PM

so ive searched and read and researched, and come up with squat. I love my car. its a phat car. its s14 240 for god sakes, but im losing faith in my car. when i start it up in the morning. (or afternoon or night) and the car is running cold, she runs like a horse in the wind. breaks loose like i want, shifts like i want, scoots like i want. Untill i get like a mile down the road and she warms up.... then all that power that i know she just had, is gone. the low end is the same, but from 3000-5500 it feels like somthing is bogging the motor down. could this be a timing issue?
(i know the timing is different during warm up) or an air fuel ratio issue? my mods are a stock air box with lower half removed and a k&n stock replacement filter. i have cleaned the MAF with carb cleaner, and the throttle body. i have no cat... on a stock exhaust.
(including pre muffler. could it be clogged?) any in put would be appreciated.

s14slide · 03-24-2003, 06:03 PM

could be something w/ the cold start system. something like the engine temp sensor getting stuck and making the ecm think the engine is cold even though it's warm and that would make it run really rich(see cold engine). could try that. do you have a CEL on? If you do, have you checked the codes?

AKADriver · 03-24-2003, 06:03 PM

Put the cat back on.

Seriously, it could be the problem. S14s are OBD2, meaning they have a second O2 sensor after the cat. When the engine's warm, the ECU will expect the cat to be working. When it sees the same O2 sensor reading before and after it may very well cut power.

And if it's not the problem, then you'll have done the responsible thing anyway. THERE IS NO REASON TO REMOVE A CATALYST FROM A STREET DRIVEN CAR.

Beyond that, check the condition of your coolant temperature sensor and its wiring to the ECU, though I don't think that's the problem if your temp gauge still works.

punkblackS14 · 03-24-2003, 06:07 PM

the only codes i have ever gotten were a 34 (knock) when using crap gas. (now using 93 religiously) and as to the cat. the previous owner gutted it.

punkblackS14 · 03-24-2003, 06:08 PM

thanks for replys.

punkblackS14 · 03-24-2003, 06:18 PM

aka...you reminded me of something... i went out side to check.
on the exhaust pipe... there is what looks like a ground strap
disconeccted after the cat

x==={=cat=}^=====premuffler======muffler
"^" is where the strap is...
x is ??? an 02 sensor? ( plugged in to a harness)

punkblackS14 · 03-24-2003, 07:17 PM

ok.... the cat im referring to like a dumbass is the dummy cat
(dumbass dumb cat heehee)

so i do have the stock cat.
which makes me ask.. should i just go ahead and replace the o2 sensor. ( this weekend im doing a plug,fuelfilter,wires tuneup)
thanx again for any response.

Red · 03-24-2003, 09:31 PM

I have the same year car. also an (se) if you find out what this is I would like to know..

I just did emmisions.. out goes the cat.

Who need clean air? I'm not breathing the stuff... the Honda is..

punkblackS14 · 03-24-2003, 09:39 PM

i posted on 240.org too.. ill let you know. btw good improvement after you lost your cat/premuffler? any problems?
and... how do you like your popcharger?

AKADriver · 03-24-2003, 09:46 PM

Quote:

Originally posted by Red
I just did emmisions.. out goes the cat. Who need clean air? I'm not breathing the stuff... the Honda is..

...

Red · 03-24-2003, 09:56 PM

The POP-Charger is nice adds some deep intake noise after and a good kick after 4000rpm.. I wish I would have got one with the full pipe to the intake tho.

The Cat will be off very soon. I have 3 options

1. Have my bro weld me one
2. Order it friday from Enjuku
3. Buy this neat maxima pipe with sound killin stuff in it and cut and refit it.

I will decide by Friday and once I get it in and on i'll let you know!

punkblackS14 · 03-24-2003, 10:11 PM

i posted on 240.org too.. ill let you know. btw good improvement after you lost your cat/premuffler? any problems?
and... how do you like your popcharger?

03-24-2003, 04:58 PM	#1
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	it runs fine when its cold. loses power when it warms up. so ive searched and read and researched, and come up with squat. I love my car. its a phat car. its s14 240 for god sakes, but im losing faith in my car. when i start it up in the morning. (or afternoon or night) and the car is running cold, she runs like a horse in the wind. breaks loose like i want, shifts like i want, scoots like i want. Untill i get like a mile down the road and she warms up.... then all that power that i know she just had, is gone. the low end is the same, but from 3000-5500 it feels like somthing is bogging the motor down. could this be a timing issue? (i know the timing is different during warm up) or an air fuel ratio issue? my mods are a stock air box with lower half removed and a k&n stock replacement filter. i have cleaned the MAF with carb cleaner, and the throttle body. i have no cat... on a stock exhaust. (including pre muffler. could it be clogged?) any in put would be appreciated. __________________ 1995 black on black leather SE powder coated black stock 5lugz homeade intake sweet cb antenna(for those road trips)

03-24-2003, 06:03 PM	#2
s14slide Zilvia Addict Join Date: Sep 2002 Location: Nippon Age: 43 Posts: 630 Trader Rating: (0) Feedback Score: 0 reviews	could be something w/ the cold start system. something like the engine temp sensor getting stuck and making the ecm think the engine is cold even though it's warm and that would make it run really rich(see cold engine). could try that. do you have a CEL on? If you do, have you checked the codes? __________________ = My day

03-24-2003, 09:31 PM	#8
Red Zilvia Addict Join Date: Feb 2002 Location: Vancouver, WA - Portland, OR Age: 44 Posts: 734 Trader Rating: (0) Feedback Score: 0 reviews	I have the same year car. also an (se) if you find out what this is I would like to know.. I just did emmisions.. out goes the cat. Who need clean air? I'm not breathing the stuff... the Honda is.. __________________ http://www.cardomain.com/memberpage/509537 http://www.imagestation.com/album/?id=4287415487 http://www.zilvia.net/f/showthread.php?t=21036

03-24-2003, 09:39 PM	#9
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	i posted on 240.org too.. ill let you know. btw good improvement after you lost your cat/premuffler? any problems? and... how do you like your popcharger? __________________ 1995 black on black leather SE powder coated black stock 5lugz homeade intake sweet cb antenna(for those road trips)

03-24-2003, 09:56 PM	#11
Red Zilvia Addict Join Date: Feb 2002 Location: Vancouver, WA - Portland, OR Age: 44 Posts: 734 Trader Rating: (0) Feedback Score: 0 reviews	The POP-Charger is nice adds some deep intake noise after and a good kick after 4000rpm.. I wish I would have got one with the full pipe to the intake tho. The Cat will be off very soon. I have 3 options 1. Have my bro weld me one 2. Order it friday from Enjuku 3. Buy this neat maxima pipe with sound killin stuff in it and cut and refit it. I will decide by Friday and once I get it in and on i'll let you know! __________________ http://www.cardomain.com/memberpage/509537 http://www.imagestation.com/album/?id=4287415487 http://www.zilvia.net/f/showthread.php?t=21036

03-24-2003, 06:03 PM	#3
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	Put the cat back on. Seriously, it could be the problem. S14s are OBD2, meaning they have a second O2 sensor after the cat. When the engine's warm, the ECU will expect the cat to be working. When it sees the same O2 sensor reading before and after it may very well cut power. And if it's not the problem, then you'll have done the responsible thing anyway. THERE IS NO REASON TO REMOVE A CATALYST FROM A STREET DRIVEN CAR. Beyond that, check the condition of your coolant temperature sensor and its wiring to the ECU, though I don't think that's the problem if your temp gauge still works.

03-24-2003, 06:07 PM	#4
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	the only codes i have ever gotten were a 34 (knock) when using crap gas. (now using 93 religiously) and as to the cat. the previous owner gutted it.

03-24-2003, 06:08 PM	#5
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	thanks for replys.

03-24-2003, 06:18 PM	#6
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	aka...you reminded me of something... i went out side to check. on the exhaust pipe... there is what looks like a ground strap disconeccted after the cat x==={=cat=}^=====premuffler======muffler "^" is where the strap is... x is ??? an 02 sensor? ( plugged in to a harness)

03-24-2003, 07:17 PM	#7
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	ok.... the cat im referring to like a dumbass is the dummy cat (dumbass dumb cat heehee) so i do have the stock cat. which makes me ask.. should i just go ahead and replace the o2 sensor. ( this weekend im doing a plug,fuelfilter,wires tuneup) thanx again for any response.

03-24-2003, 10:11 PM	#12
punkblackS14 Join Date: Mar 2003 Location: Tulsa Oklahoma Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	i posted on 240.org too.. ill let you know. btw good improvement after you lost your cat/premuffler? any problems? and... how do you like your popcharger? __________________ 1995 black on black leather SE powder coated black stock 5lugz homeade intake sweet cb antenna(for those road trips)