SR20DET helppp - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

flip3d · 02-11-2008, 05:54 PM

K, I just finished swapping in my redtop. I have spark, fuel, and she starts right up.

Now here's the problem. When I start it up, it immediately revs to 2000RPMs and stay for a few seconds before jumping to 4000RPMs. I kinda get scared and turn the car off before it gets any higher than that. ECU was throwing a code 34 which is the knock sensor. Turned out that it was bad gas and tons of rust in the tank. So I got that fixed. No rust in the tank and fresh 93, code 55, but the problem is still there. It smells like the car is running really rich. I'm not sure of the condition of the turbo. Could a bad turbo cause the RPMs to just go up.

Gjohnson7 · 02-11-2008, 06:54 PM

What have you checked out so far?

I would probably start with the idle adjustement screw located on the throttle body. I picked up a 90 SOHC a while back that needed a timing chain. When I finally put everything back together, I had the same problem. I tried trouble shooting the problem for about 2 weeks and found that the retard that had the car before me, had replaced the small screw with a larger one and had screwed that bad boy in. Apparently, he was trying to avoid any timing chain rattle by setting the idle higher.

Also, check TPS and MAF.

180sx_Drifter · 02-11-2008, 06:57 PM

check your IACV and adjust it. if that doesnt work check your maf.

flip3d · 02-11-2008, 09:10 PM

I havent really messed with the IACV yet but I have a brand new Z32 MAF. So I guess I'll switch the TPS and play with the IACV tomorrow and let you guys know.

I just find it strange how it just revs up to 4000+RPMs. It sits at 2000 for 10 seconds then all of a sudden the RPMS shoot up like its at WOT.

flip3d · 02-12-2008, 12:29 PM

Swapped the throttle body and turned the screw on the IACV. It idles around 1200-1500RPM and it doesnt rev on its own but now it backfires like a bitch and the throttle isnt very responsive. Also, It flashed code 11 but it went away.

Any ideas?

*fliprayzin240sx* · 02-12-2008, 01:47 PM

You using anything to convert the signal for that Z-maf? Do the usual stuff, adjust your IACV, double check timing, do a boost leak test...

turboboost12004 · 02-12-2008, 01:56 PM

sounds like it could be vacumm leak...but idk....aicv...what about timing..check that also

02-11-2008, 05:54 PM	#1
flip3d Zilvia FREAK! Join Date: Feb 2008 Location: Ft Lauderdale, FL Age: 37 Posts: 1,473 Trader Rating: (1) Feedback Score: 1 reviews	SR20DET helppp K, I just finished swapping in my redtop. I have spark, fuel, and she starts right up. Now here's the problem. When I start it up, it immediately revs to 2000RPMs and stay for a few seconds before jumping to 4000RPMs. I kinda get scared and turn the car off before it gets any higher than that. ECU was throwing a code 34 which is the knock sensor. Turned out that it was bad gas and tons of rust in the tank. So I got that fixed. No rust in the tank and fresh 93, code 55, but the problem is still there. It smells like the car is running really rich. I'm not sure of the condition of the turbo. Could a bad turbo cause the RPMs to just go up.

02-11-2008, 06:54 PM	#2
Gjohnson7 Zilvia Addict Join Date: Mar 2004 Location: Broken Arrow, OK Age: 44 Posts: 980 Trader Rating: (7) Feedback Score: 7 reviews	What have you checked out so far? I would probably start with the idle adjustement screw located on the throttle body. I picked up a 90 SOHC a while back that needed a timing chain. When I finally put everything back together, I had the same problem. I tried trouble shooting the problem for about 2 weeks and found that the retard that had the car before me, had replaced the small screw with a larger one and had screwed that bad boy in. Apparently, he was trying to avoid any timing chain rattle by setting the idle higher. Also, check TPS and MAF. __________________ LSX Kouki Project, swap completed in Dec 09

02-11-2008, 06:57 PM	#3
180sx_Drifter Zilvia Junkie Join Date: Jan 2008 Location: SoCal Posts: 557 Trader Rating: (1) Rides Gallery: 180sx_Drifter Feedback Score: 1 reviews	check your IACV and adjust it. if that doesnt work check your maf. __________________

02-12-2008, 01:47 PM	#6
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	You using anything to convert the signal for that Z-maf? Do the usual stuff, adjust your IACV, double check timing, do a boost leak test... __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

02-12-2008, 01:56 PM	#7
turboboost12004 Zilvia Junkie Join Date: Jun 2004 Location: california Posts: 418 Trader Rating: (8) Feedback Score: 8 reviews	sounds like it could be vacumm leak...but idk....aicv...what about timing..check that also __________________ Sieze the day or Die regreting the time you lost

02-11-2008, 09:10 PM	#4
flip3d Zilvia FREAK! Join Date: Feb 2008 Location: Ft Lauderdale, FL Age: 37 Posts: 1,473 Trader Rating: (1) Feedback Score: 1 reviews	I havent really messed with the IACV yet but I have a brand new Z32 MAF. So I guess I'll switch the TPS and play with the IACV tomorrow and let you guys know. I just find it strange how it just revs up to 4000+RPMs. It sits at 2000 for 10 seconds then all of a sudden the RPMS shoot up like its at WOT.

02-12-2008, 12:29 PM	#5
flip3d Zilvia FREAK! Join Date: Feb 2008 Location: Ft Lauderdale, FL Age: 37 Posts: 1,473 Trader Rating: (1) Feedback Score: 1 reviews	Swapped the throttle body and turned the screw on the IACV. It idles around 1200-1500RPM and it doesnt rev on its own but now it backfires like a bitch and the throttle isnt very responsive. Also, It flashed code 11 but it went away. Any ideas?