# 99 B14 Sentra GXE 1.6L Stalls after start



## jamesm113 (Jun 20, 2010)

Hello,
I have a 99 Nissan Sentra GXE (1.6L engine) with approximately 145K miles that is stalling immediately after starting.


Manual transmission
Happens only when the engine is slightly warm (temp gauge approximately less than 25% of the way up)
Pushing on the throttle seems to help sometimes
Hot starts and cold starts work fine

Any ideas what this could be? No CEL or any other issues I'm aware of.

Thanks!


----------



## Michael Geyer (Mar 28, 2014)

Clean out the IACV and it's ports, scrub out the throttle body a bit, check/adjust the TPS, check/adjust the timing, check/adjust the minimum idle rpm. No sense in spending $$$ on parts until you got the basics done.


----------



## jamesm113 (Jun 20, 2010)

Ok did that all. Issue still persists. Any other ideas?


----------



## azkicker0027 (May 31, 2002)

this does sound like a bad idle valve. only partial opening of the throttle plate keeps it alive. 
if you can, maybe look at the oxygen sensor status when this happens, with an OBD scanner. just a slight possibility that the open and closed loop status of the ECU affects this condition.


----------



## jamesm113 (Jun 20, 2010)

Sorry for not posting in a while. The IACV was fine. Turned on headlights/AC/rear defroster/etc all at once, idle remained steady. Turned everything off, idle remained steady.

Anyway, about 3 weeks ago, the battery died (it was over 9 years old). 

Since replacing it, the issue hasn't come back at all.

Thanks!


----------



## jamesm113 (Jun 20, 2010)

Well, about 10 months later, the issue has come back.

Measured 12.6V battery at rest, 13.9V-14V when car was idling.


----------



## jdg (Aug 27, 2009)

Can you and/or have you set the base idle and timing according the to the "procedure"?


----------



## jamesm113 (Jun 20, 2010)

Ok base idle was way low, in 325 range (was using the dash tach). I've re-adjusted it 625 (spec'd in manual for MT).

Timing was a little tricky for me. It seemed to be about 8 degrees, but the notches would only appear in the light every 10 seconds or so.

I also have a california car with an aftermarket hood, so I'm not sure what the california model timing/base idle specs are supposed to be.

EDIT: I also managed to misplace the base idle rubber cap. Is that important?


----------



## jdg (Aug 27, 2009)

Rubber cap - not really, doesn't let any air leak in and if it would, it would be a really small amount. Tape it up, call it good.
Timing - turn the clamp that goes on the plug wires around. Helps sometimes.
Base idle - 325-ish surely isn't going to help much...but make double damn sure you're doing the timing correctly (eg. according to the procedure). Each time I do it, seems like it takes me a few tries to get it right and I've done it at least a dozen times or so.
Idle spec's - should be listed on that emissions sticker under the hood. Don't have my book handy. Maybe later...


----------



## jamesm113 (Jun 20, 2010)

Ok, I'll definitely redo the whole procedure. I have the FSM workflow chart pulled up and printed out. It does say to honor whatever's on the hood, but since my hood was replaced by a body shop, it does not have the emissions sticker. I'll stick with the FSM specs (625rpm & 8 degrees BTDC).

I was previously using the haynes manual, which stated I should keep the engine at 1,000RPM. However, that was next to impossible as it would rev to 1500 RPM or idle - pretty much impossible to hold steady at 1K. But reading the FSM procedure I should keep it @ 2000 instead.

Just a few things left unclear now.
* ECM self-diagnosis? Can I do without the fancy Nissan scan tool? 
* Diagnostic test mode II? is this required? I think this pdf has the procedure outlined- http://g35driver.com/forums/attachments/drivetrain/44119d1149091264-tranny-programming-5at-ec64.pdf
* When unplugging the TPS, do you unplug both connectors or just one? I was unplugging both in the previous attempt

Sorry if these are dumb questions, just wanted to get this done properly.

Thanks!


----------



## jdg (Aug 27, 2009)

1- Yes, procedures are in the sticky threads
2- Don't know why you'd need it
3- It's in the sticky thread that talks about setting the timing/idle. Yes, it's 4+ pages. Yes, it has good info. There's only one TPS connector.

Idle rpm - 1,000 is practically impossible. It's called "idle follower logic". ECM assumes that below a certain percentage of throttle, your foot is off the gas and tries to maintain just the base idle. Once you get above a certain percentage, the ECM quits trying to maintain the idle and lets the butterfly valves do the work. By that time, the engine might want to rev to 2,000 or so. That's one indication your base idle/timing isn't set right. I can get mine to either idle or around 1,300 rpm or so. That 1,300 rpm value is going to be a tad bit different for everybody depending on engine age, altitude, gas quality, blah blah blah, but I wouldn't think it should be much higher than 1,500 or so. You'll know if you're in "base idle/timing set mode" if the engine is idling along, and you turn on the headlights, A/C, blower motor, etc. and the engine doesn't hold the idle and tries to die off because of the extra load.


----------



## jamesm113 (Jun 20, 2010)

Is this the timing/base idle sticky you are referring to? It's for a 91-94 sentra, which only has one TPS connector. It also says the base idle should be adjusted _before_ the timing, where as the FSM suggests otherwise.

The 95-99 sentras have two connectors. Here's a picture- http://mlm-s2-p.mlstatic.com/sensor...-original-vmj-1160-MLM4733654085_072013-F.jpg Do I just unplug both?

Still searching for the ECM self-diagnosis mode...

Thanks!


----------



## jdg (Aug 27, 2009)

Nope, that sticky covers what you need. The timing is different between 91-94 and 95-99, and yes, the TPS is different between the B13 and B14, automatic and manual.

And, crap, you're right about the TPS. That's what I get for having too many make/models of vehicles. I get them confused once in awhile. TPS is the red connector, Idle switch is the black one. You want the TPS.

Base idle and timing are checked/set at the same time as they both affect each other. If you set the idle, then have to raise the timing, the idle will likely go up a bit. If you have to bump the timing back, the idle might go down a bit. Basically, you set the idle, set the timing, check the idle, check the timing, go back and forth until both are good...or good enough.

ECM diagnosis is right there next to the sticky for the timing.


----------



## jamesm113 (Jun 20, 2010)

Ah, at the bottom of this thread I see a switch on the ECM for "Self-diagnose" mode select. I'll do that.

I didn't see any sticky's related to the ECM, etc in the GA16DE sub-forum, where the timing sticky was located. Sorry I get so easily confused.

And OK, did some googling and figured out what the idle switch is. I'll be sure to leave that plugged in this time around, but I'll also ensure proper operation according to the instructions here/ the FSM.


Thanks!


----------

