SR20 swap, no low throttle - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

1320VR4 · 10-01-2012, 02:46 PM

Ok this is hard to explain so I'm going to do my best but if you need clarification or a video I'd be happy to post further.

Anyhow I swapped in an SR20det blacktop into my 240. Everything runs fine, idles normal, has alot of power, etc. The only issue is that I have no low throttle.

For instance in neutral, if you slowly apply throttle, nothing happens until a point where it's like all of a sudden the spark plugs start to fire and the rpms climb however once they "catch on" the revvs climb to redline, it would be impossible to hold it at say, 3,000 rpm.

When driving there is no low throttle, I constantly have to accelerate and let off the gas over and over to maintain speed. I can't just hold a steady throttle placement and hold say 45mph, either I have to depress the throttle far enough where I will cross the threshold so to speak and the car will accelearate, if I slowly let up on the throttle it hits a point where it just cuts and coasts like you let off the accelerator all together.

I can't be certain but I think the injectors are still firing, the spark system just isn't sparking at low throttle....odd. I don't even know what to search for on here to try and remedy the issue

help? lol
-Matt

beems240sx · 10-01-2012, 02:52 PM

throttle position sensor? maybe it has a dead spot

1320VR4 · 10-01-2012, 03:36 PM

Any chance KA and SR sensors are the same? I checked the tps at idle to see if it was right while looking for vacuum leaks but I didn't check for the full motion since I can't find my alligator clips

beems240sx · 10-01-2012, 03:43 PM

if i remember it should be .45v closed. slowly move it with a mutli meter and watch the voltages. see if it jumps. pretty sure they are different sensors, but i cant confirm

godsmack · 10-01-2012, 08:05 PM

does it rev properly if you move the throttle body by hand?

steve shadows · 10-01-2012, 09:18 PM

Sounds like bad data into the ecm, probably timing is waaaay off and/or tps is bad....and/or maf is screwy. Yeah check if it does the same sitting without driving i.e. TB as previous poster above me mentioned as well.

10-01-2012, 02:46 PM	#1
1320VR4 Zilvia Member Join Date: Mar 2012 Location: Vernon, NJ Age: 31 Posts: 269 Trader Rating: (4) Feedback Score: 4 reviews	SR20 swap, no low throttle Ok this is hard to explain so I'm going to do my best but if you need clarification or a video I'd be happy to post further. Anyhow I swapped in an SR20det blacktop into my 240. Everything runs fine, idles normal, has alot of power, etc. The only issue is that I have no low throttle. For instance in neutral, if you slowly apply throttle, nothing happens until a point where it's like all of a sudden the spark plugs start to fire and the rpms climb however once they "catch on" the revvs climb to redline, it would be impossible to hold it at say, 3,000 rpm. When driving there is no low throttle, I constantly have to accelerate and let off the gas over and over to maintain speed. I can't just hold a steady throttle placement and hold say 45mph, either I have to depress the throttle far enough where I will cross the threshold so to speak and the car will accelearate, if I slowly let up on the throttle it hits a point where it just cuts and coasts like you let off the accelerator all together. I can't be certain but I think the injectors are still firing, the spark system just isn't sparking at low throttle....odd. I don't even know what to search for on here to try and remedy the issue help? lol -Matt __________________ 94 240SX, 93 Stealth, 92 VR4, 93 RX7 , 88 Yota

10-01-2012, 03:36 PM	#3
1320VR4 Zilvia Member Join Date: Mar 2012 Location: Vernon, NJ Age: 31 Posts: 269 Trader Rating: (4) Feedback Score: 4 reviews	Any chance KA and SR sensors are the same? I checked the tps at idle to see if it was right while looking for vacuum leaks but I didn't check for the full motion since I can't find my alligator clips __________________ 94 240SX, 93 Stealth, 92 VR4, 93 RX7 , 88 Yota

10-01-2012, 09:18 PM	#6
steve shadows Post Whore! Join Date: Aug 2003 Location: LA and OC Posts: 8,202 Trader Rating: (5) Feedback Score: 5 reviews	Sounds like bad data into the ecm, probably timing is waaaay off and/or tps is bad....and/or maf is screwy. Yeah check if it does the same sitting without driving i.e. TB as previous poster above me mentioned as well. __________________ Like Me on FaceBook !

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10-01-2012, 02:52 PM	#2
beems240sx Zilvia FREAK! Join Date: Jun 2008 Location: Phoenix Posts: 1,135 Trader Rating: (10) Feedback Score: 10 reviews	throttle position sensor? maybe it has a dead spot

10-01-2012, 03:43 PM	#4
beems240sx Zilvia FREAK! Join Date: Jun 2008 Location: Phoenix Posts: 1,135 Trader Rating: (10) Feedback Score: 10 reviews	if i remember it should be .45v closed. slowly move it with a mutli meter and watch the voltages. see if it jumps. pretty sure they are different sensors, but i cant confirm

10-01-2012, 08:05 PM	#5
godsmack Zilvia Addict Join Date: Feb 2009 Location: Allentown, PA Age: 36 Posts: 652 Trader Rating: (0) Feedback Score: 0 reviews	does it rev properly if you move the throttle body by hand?