SR Hesitation, etc. Please confirm. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

fredbblakemore · 09-10-2005, 09:52 AM

I'm experiencing the hesitation, stumbling, and overall weak performance issues explained by many other zilvians. I'm in the process of going through the FSM, old tech threads, etc. to dianose/fix the problem. Below are some comments and questions. Let me know if you have any feedback.

1. Phase2's explanation for setting base timing has either been removed or I have the link wrong (http://www.store.yahoo.com/phase2mot...tosetcaso.html). Does anyone know another "how to" aside from Phase2 and the FSM? I want to read as many write-ups as possible to make sure I'm setting things right.

2. I think I've eliminated the TPS as the culprit. I have a zeitronix wideband/datalogger that's connected to the TPS line on the ECU. The datalogger software reads a minimum value of 7 or 8 and a maximum value of 90. Seems legit.

3. When the engine is set to 15BTDC, it seems to idle okay but once you touch the throttle (either medium or wide open) it really bogs and feels like it wants to stall. I'm going to reconfirm the method of checking the timing with the FSM (warming up, revving, disconnect TPS, etc.) and make sure that I'm getting good readings. I'm using a cheap (Actron Incudive CP7507) timing light as suggested.

4. When the engine bogs (after touching the throttle from idle), the wideband reads really rich. I suppose this could be a few things. Air leak to the intake manifold, timing of ignition, bad ignition (coil packs?), too much fuel from injectors, etc. I'm going to start checking each of these individually. When the bogging ends, the wideband is reading around ideal.

5. When the timing is advanced to (what I think is) about 30BTDC, the hesitation and stumbling is mostly gone down low but the top end (3.5K+rpm) still has no power. I can see steady, full boost of about 7lbs. (on this shitty test meter I'm using) but there is no pull. This sounds like timing to me but I'm not sure.

6. The CAS cover was cracked so I opened it up and inspected the wheel. Everything looks perfect. I rigged it up temporarily (until I can order a new cover). What's the easiest way to check for a faulty CAS?

7. My E5 ECU has no LED inside. WTF is up with that? Is there another way to check the diagnosic shiz?

8. I've tried a few MAFS. One from my S13 SOHC which ran fine before I pulled it, and one from S13 SR. Engine performs the same way with both so I think it's unlikely that the MAFS is the problem.

Here's some info about my setup:
-S13 BlackTop SR
-E5 ECU
-wiring done professionally by a reputable guy
-cometic metal head gasket
-blitz intake filter
-S14 T28 turbo
-medium sized FMIC
-MR turbo manifold
-full 3" exhaust
-stock injectors
-Koyo aluminum rad.
-SPAL dual 11" electric fans

Let me know what you think. Thanks in advance for your help.

09-10-2005, 09:52 AM	#1
fredbblakemore Leaky Injector Join Date: Aug 2004 Location: Michigan Posts: 80 Trader Rating: (0) Feedback Score: 0 reviews	SR Hesitation, etc. Please confirm. I'm experiencing the hesitation, stumbling, and overall weak performance issues explained by many other zilvians. I'm in the process of going through the FSM, old tech threads, etc. to dianose/fix the problem. Below are some comments and questions. Let me know if you have any feedback. 1. Phase2's explanation for setting base timing has either been removed or I have the link wrong (http://www.store.yahoo.com/phase2mot...tosetcaso.html). Does anyone know another "how to" aside from Phase2 and the FSM? I want to read as many write-ups as possible to make sure I'm setting things right. 2. I think I've eliminated the TPS as the culprit. I have a zeitronix wideband/datalogger that's connected to the TPS line on the ECU. The datalogger software reads a minimum value of 7 or 8 and a maximum value of 90. Seems legit. 3. When the engine is set to 15BTDC, it seems to idle okay but once you touch the throttle (either medium or wide open) it really bogs and feels like it wants to stall. I'm going to reconfirm the method of checking the timing with the FSM (warming up, revving, disconnect TPS, etc.) and make sure that I'm getting good readings. I'm using a cheap (Actron Incudive CP7507) timing light as suggested. 4. When the engine bogs (after touching the throttle from idle), the wideband reads really rich. I suppose this could be a few things. Air leak to the intake manifold, timing of ignition, bad ignition (coil packs?), too much fuel from injectors, etc. I'm going to start checking each of these individually. When the bogging ends, the wideband is reading around ideal. 5. When the timing is advanced to (what I think is) about 30BTDC, the hesitation and stumbling is mostly gone down low but the top end (3.5K+rpm) still has no power. I can see steady, full boost of about 7lbs. (on this shitty test meter I'm using) but there is no pull. This sounds like timing to me but I'm not sure. 6. The CAS cover was cracked so I opened it up and inspected the wheel. Everything looks perfect. I rigged it up temporarily (until I can order a new cover). What's the easiest way to check for a faulty CAS? 7. My E5 ECU has no LED inside. WTF is up with that? Is there another way to check the diagnosic shiz? 8. I've tried a few MAFS. One from my S13 SOHC which ran fine before I pulled it, and one from S13 SR. Engine performs the same way with both so I think it's unlikely that the MAFS is the problem. Here's some info about my setup: -S13 BlackTop SR -E5 ECU -wiring done professionally by a reputable guy -cometic metal head gasket -blitz intake filter -S14 T28 turbo -medium sized FMIC -MR turbo manifold -full 3" exhaust -stock injectors -Koyo aluminum rad. -SPAL dual 11" electric fans Let me know what you think. Thanks in advance for your help.