SR starts, runs like s**t... help troubleshoot! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kazuo · 03-01-2003, 04:21 PM

Okay!

So, the car starts, it seems to idle okay, and If I rev it, it (apparently) produces boost since the BOV goes off.

When I put it in gear and try to drive it, it runs like its about to fall over and die. It sputters, bucks, and it spits all kinds of nasty black fumes out of the exhaust.

I changed the fuel pump to a high-pressure Walbro pump, and I'm also using a KA24E MAFS with a generic cone filter. The o2 sensor is *not* hooked up (could this be causing the problem?). I connected the black/yellow wires as HeavyThrottle mentioned in their wiring FAQ . As far as I can figure, everything is hooked up properly.

Does anyone have any guesses as to why this is happening?

Also, I am not sure, but I believe that the turbo may not be producing boost. It's strange, because, as I mentioned, the BOV will release air when I initially start the car and rev it up, but when I tried driving it back and forth down the block, I never heard it go off.

Is there any way I can check if its producing boost that doesnt involve using a boost gauge (I don't have one yet; its on the way)? What are some of the most likeliest things that would cause it not to produce boost?

I really appreciate the help. I'm still learning... the hard way :P

autobahNESSA · 03-02-2003, 02:25 PM

Just get ur damn car running so you can help me fix my car!

put back on the stock recuirc valve and get it running. Plugg in the 02 smart guy. Make sure u hook up all the vacum lines..

I dont know where they go but get them hooked up and help me out with mine.

Lates

xsboost · 03-02-2003, 08:20 PM

Run a vacuum line into the car (you have to for the Boost gauge anyway) You should hear hissing under vacuum (cruise idle and such), once you go into boost it will get quiet for a sec then you can feel air coming out of it.

As for the studdering make sure there are no leaks on your IC piping or from the MAF to the turbo. Check the wiring on the MAF and the TPS. The 02 will affect it but not like that. Also find the ground wire on your MAF and tap into it and run another ground to it. Should help a bit. Make sure all of the engine grounds are done and good.. A loose ground will make life hell.

Danny

drift freaq · 03-03-2003, 12:23 AM

make sure your getting a good vacuum line to the blowoff valve . Best place to get it is directly off the intake you should have a vacuum out right by your throttle body. Next thing is to make sure all your piping is tight. you may need to check your timing . Depending on where your got your engine from timing can be off. Oh yeah 15 degrees BTDC is what you want timing wise

andrave · 03-03-2003, 12:22 PM

It sounds like a timing problem to me, I've had the exact same thing happen, only on NA cars. As far the stuttering, I've heard that a BOV on a stock computer can make it stumble.. any truth in that?

03-01-2003, 04:21 PM	#1
kazuo Post Whore! Join Date: Aug 2002 Location: Posts: 2,762 Trader Rating: (3) Feedback Score: 3 reviews	SR starts, runs like st... help troubleshoot!** Okay! So, the car starts, it seems to idle okay, and If I rev it, it (apparently) produces boost since the BOV goes off. When I put it in gear and try to drive it, it runs like its about to fall over and die. It sputters, bucks, and it spits all kinds of nasty black fumes out of the exhaust. I changed the fuel pump to a high-pressure Walbro pump, and I'm also using a KA24E MAFS with a generic cone filter. The o2 sensor is not hooked up (could this be causing the problem?). I connected the black/yellow wires as HeavyThrottle mentioned in their wiring FAQ . As far as I can figure, everything is hooked up properly. Does anyone have any guesses as to why this is happening? Also, I am not sure, but I believe that the turbo may not be producing boost. It's strange, because, as I mentioned, the BOV will release air when I initially start the car and rev it up, but when I tried driving it back and forth down the block, I never heard it go off. Is there any way I can check if its producing boost that doesnt involve using a boost gauge (I don't have one yet; its on the way)? What are some of the most likeliest things that would cause it not to produce boost? I really appreciate the help. I'm still learning... the hard way :P

03-02-2003, 08:20 PM	#3
xsboost Join Date: Feb 2003 Location: Little Rock, AR Age: 45 Posts: 26 Trader Rating: (0) Feedback Score: 0 reviews	Run a vacuum line into the car (you have to for the Boost gauge anyway) You should hear hissing under vacuum (cruise idle and such), once you go into boost it will get quiet for a sec then you can feel air coming out of it. As for the studdering make sure there are no leaks on your IC piping or from the MAF to the turbo. Check the wiring on the MAF and the TPS. The 02 will affect it but not like that. Also find the ground wire on your MAF and tap into it and run another ground to it. Should help a bit. Make sure all of the engine grounds are done and good.. A loose ground will make life hell. Danny __________________ 91 Hatch, SR20DET, Polk Performance Turbo Kit, TEC II computer, 11.9@116mph

03-03-2003, 12:23 AM	#4
drift freaq R.I.P. Aya, always love Join Date: Nov 2001 Location: Los Feliz/Hollywood Posts: 18,564 Trader Rating: (215) Rides Gallery: drift freaq Feedback Score: 215 reviews	make sure your getting a good vacuum line to the blowoff valve . Best place to get it is directly off the intake you should have a vacuum out right by your throttle body. Next thing is to make sure all your piping is tight. you may need to check your timing . Depending on where your got your engine from timing can be off. Oh yeah 15 degrees BTDC is what you want timing wise __________________ "Having a lot of tracks on a song is like putting stickers on a car to get more horsepower" New Video https://www.youtube.com/watch?v=uebV1OnbRsw Buy my mounts! http://zilvia.net/f/sale-items/51531...ns-mounts.html http://zilvia.net/f/tech-talk/317539...e-mouts-6.html

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03-02-2003, 02:25 PM	#2
autobahNESSA Zilvia FREAK! Join Date: Aug 2002 Location: Milpitas/Irvine, CA Posts: 1,257 Trader Rating: (3) Feedback Score: 3 reviews	Just get ur damn car running so you can help me fix my car! put back on the stock recuirc valve and get it running. Plugg in the 02 smart guy. Make sure u hook up all the vacum lines.. I dont know where they go but get them hooked up and help me out with mine. Lates

03-03-2003, 12:22 PM	#5
andrave BANNED Join Date: Apr 2002 Location: Burton WV Posts: 2,350 Trader Rating: (0) Feedback Score: 0 reviews	It sounds like a timing problem to me, I've had the exact same thing happen, only on NA cars. As far the stuttering, I've heard that a BOV on a stock computer can make it stumble.. any truth in that?