help? my car sounds like a v8 and its bonestock? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sk8fish2012 · 05-30-2013, 09:09 AM

I have a 91 hatch with a KA24DE from a 97 kouki and for some reason its been running really rough at idle and it sounds like its got bigger cams and a stroker kit in it but it just runs like crap. under load its fine but I cant find the problem, fuel pressure is alittle high, its not starving for fuel but at idle its running almost 100% lean when we checked it with a gas analyzer. MAF is clean and reading correctly the only thing I can think of is possibly the Throttle Position Sensor, any ideas?

EsChassisLove · 05-30-2013, 09:33 AM

You're not firing on one cylinder.

Sounds like a boxer engine yea?

sk8fish2012 · 05-30-2013, 09:37 AM

no misfires at all actually, I forgot to mention that, it sits and lopes really heavily at idle almost like its got to big of a cam in it but all the internals are bonestock

jr_ss · 05-30-2013, 10:30 AM

Compression test? Sounds like you have a dead cylinder.

Kingtal0n · 05-30-2013, 10:55 AM

Naw it sounds like the IACV is stuck open letting in gobs of air, but the fuel cut is keeping the engine from injecting extra fuel so you wind up with a lope. (verify by manually adjusting the TPS such that the engine thinks the throttle valve is open some, the engine should sudden raise in RPM significantly and sound somewhat normal except high idle) Just to clarify, remove the tps and adjust it by hand while is is plugged in. Or unplug the TPS on the engine, and plug in an extra tps you have laying around.

Change the IACV it should be throwing a code.

This is what it would be on an SR20, KA I dont have much experience usually yank those out right away hehe.

Frank_Jaeger · 05-30-2013, 01:50 PM

Could it have jumped timing?

sk8fish2012 · 05-31-2013, 02:25 PM

no codes, ill recheck timing when I get the chance, last time I was able to get it to 16-17 btdc and I couldn't get it any closer so ill check the chain and make sure its not jumped,

Kingtal0n · 05-31-2013, 02:27 PM

Quote:

Originally Posted by sk8fish2012

no codes, ill recheck timing when I get the chance, last time I was able to get it to 16-17 btdc and I couldn't get it any closer so ill check the chain and make sure its not jumped,

did you do what I suggested? it takes 3 minutes to move the tps by hand and verify the iacv is the culprit.

Otherwise, yes it could very well be the timing chain has jumped. better hope not because then the question is... why? how?

Zenk1_love · 06-03-2013, 08:29 PM

Headgasket? My s13 single cam did the same thing. Sounded really lopey at idle but ran like crap, although it smoothed out if I got on it. What's your exhaust look like? Any smoke?

sk8fish2012 · 06-05-2013, 12:42 PM

the only "smoke" I can see is unburnt fuel, no sweet smell to it, on the hotter days it smells like a lawn mower in a way how it just smells like gas if that makes sense

05-30-2013, 09:09 AM	#1
sk8fish2012 Join Date: Feb 2013 Location: Sun Prairie, WI Age: 27 Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	help? my car sounds like a v8 and its bonestock? I have a 91 hatch with a KA24DE from a 97 kouki and for some reason its been running really rough at idle and it sounds like its got bigger cams and a stroker kit in it but it just runs like crap. under load its fine but I cant find the problem, fuel pressure is alittle high, its not starving for fuel but at idle its running almost 100% lean when we checked it with a gas analyzer. MAF is clean and reading correctly the only thing I can think of is possibly the Throttle Position Sensor, any ideas?

05-30-2013, 09:33 AM	#2
EsChassisLove Nissanaholic! Join Date: Jan 2011 Location: San Diego Age: 32 Posts: 2,090 Trader Rating: (26) Feedback Score: 26 reviews	You're not firing on one cylinder. Sounds like a boxer engine yea? __________________ IG/TikTok-ThatS14_Z06guy

05-30-2013, 10:30 AM	#4
jr_ss Post Whore! Join Date: Dec 2005 Location: Pa Posts: 6,056 Trader Rating: (34) Feedback Score: 34 reviews	Compression test? Sounds like you have a dead cylinder. __________________ My SR20VET

05-30-2013, 10:55 AM	#5
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	Naw it sounds like the IACV is stuck open letting in gobs of air, but the fuel cut is keeping the engine from injecting extra fuel so you wind up with a lope. (verify by manually adjusting the TPS such that the engine thinks the throttle valve is open some, the engine should sudden raise in RPM significantly and sound somewhat normal except high idle) Just to clarify, remove the tps and adjust it by hand while is is plugged in. Or unplug the TPS on the engine, and plug in an extra tps you have laying around. Change the IACV it should be throwing a code. This is what it would be on an SR20, KA I dont have much experience usually yank those out right away hehe. __________________ 5.3/4l80e/turbo 240sx playthrough: https://tinyurl.com/turbo240

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05-30-2013, 09:37 AM	#3
sk8fish2012 Join Date: Feb 2013 Location: Sun Prairie, WI Age: 27 Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	no misfires at all actually, I forgot to mention that, it sits and lopes really heavily at idle almost like its got to big of a cam in it but all the internals are bonestock

05-30-2013, 01:50 PM	#6
Frank_Jaeger Zilvia FREAK! Join Date: Jan 2012 Location: Port Charlotte, Florida Age: 29 Posts: 1,352 Trader Rating: (1) Feedback Score: 1 reviews	Could it have jumped timing?

05-31-2013, 02:25 PM	#7
sk8fish2012 Join Date: Feb 2013 Location: Sun Prairie, WI Age: 27 Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	no codes, ill recheck timing when I get the chance, last time I was able to get it to 16-17 btdc and I couldn't get it any closer so ill check the chain and make sure its not jumped,

06-03-2013, 08:29 PM	#9
Zenk1_love Leaky Injector Join Date: Jul 2010 Location: CHS Age: 30 Posts: 83 Trader Rating: (2) Feedback Score: 2 reviews	Headgasket? My s13 single cam did the same thing. Sounded really lopey at idle but ran like crap, although it smoothed out if I got on it. What's your exhaust look like? Any smoke?

06-05-2013, 12:42 PM	#10
sk8fish2012 Join Date: Feb 2013 Location: Sun Prairie, WI Age: 27 Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	the only "smoke" I can see is unburnt fuel, no sweet smell to it, on the hotter days it smells like a lawn mower in a way how it just smells like gas if that makes sense