car dies when decelerating in neutral, IAC checks out good?

[1Gina2G]

Okay everyone theres alot of threads about this exact issue but most commonly from BOVs that aren't recirculated or a bad IAC along with boost leaks. I have no leaks from putting the tester on the turbo inlet and all 6 of my pins on my tan IAC ohm out to 32, the black IAC goes up to 40 or so. My 1G BOV sounds like it functions but sometimes it does sound fultterly but this is my first dsm.

Basically if i shift into neutral, and if the clutch is let off as quick as you want the car shuts off, if i slowly let off the clutch it will not stall while slowing into neutral.

Should i BLT somewhere else? Like the throttle elbow? Im looking into checking the harness plug itself but not sure how.

is it safe to drive with the IAC unplugged?i dont want to fry my ecu

 

[Lawlipop]

So, what if you just press the clutch in and don't let it out, does it still do it?

Do you have the hose on the outlet of the bov connected to the intake pipe still (recirculated)?

 

[1Gina2G]

So, what if you just press the clutch in and don't let it out, does it still do it?

Do you have the hose on the outlet of the bov connected to the intake pipe still (recirculated)?

the car won't stall until until the clutch is released rapidly upon shifting into neutral. with that said, I haven't tried to hold it in for any bit longer then normal use.

the big recirculation tube is connected to the intake pipe, also appears to be holding in boost. the smaller hose goes to a nipple on the intake manifold to the BOV.

sometimes when I shift, making my way to fith gear, sometimes I don't even hear it, this is with all hard intercooler piping too. I can usually hear it %90 of the time, but more times then not when it goes off it sounds a lot quieter then a loud air release noise, like a suppressed noise. One thing I have noticed about the BOV is it seems its loudest once finally in fith gear, especially at higher speeds.

I was wondering about unplugging the IAC to see if it would still stall, I know the car will run with it unplugged from having it unplugged accidently once before.

 

[Lawlipop]

The thing that would make it the bov would be venting that would cause it to stall the car. If it only happens when you let up the clutch pedal and not just if you press the clutch in fast, then it could be in the drivetrain. The iac is going to try to adjust to idle whether you keep the clutch pressed in, or put it in neutral.

 

[1Gina2G]

wow really? drivetrain related? wouldn't have ever thought that. The transmission is rebuilt very recently with going on 300 first miles with 80w-90 GL5 gear oil(for yellow metals) along with the same oil in the transfer case and rear diff. my rear diff looks rough on the outside, im sure it could use a rebuild, supposively the dealership rebuilt the T-case just a few years ago for the recalls.

with that said, I have made another thread about my car, probably something with the transmission, is hesistant in 2nd gear especially, but also 3rd.

not sure what I should check next, the car idles and drives good otherwise..

 

[1995silvergst]

couple things to help clarify here, first is this the original motor or was it swapped? What are your W/B readings when it occurs? Are you logging this car? What is the logger/ecu showing for vehicle speed vs your speedometer? Have your tried to just hold the clutch in and coast with it in and out of gear? And if you decelerate in gear letting the motor drag down to idle speed then push in the clutch what happens?

 

[Lawlipop]

I don't think we understand exactly why's going on, if it only does it when you put it in neutral and not when you coast with the clutch pressed in, it wouldnt be iac related. Do the rpms move when your idling and press in the clutch?

 

[1Gina2G]

couple things to help clarify here, first is this the original motor or was it swapped? What are your W/B readings when it occurs? Are you logging this car? What is the logger/ecu showing for vehicle speed vs your speedometer? Have your tried to just hold the clutch in and coast with it in and out of gear? And if you decelerate in gear letting the motor drag down to idle speed then push in the clutch what happens?

this is a rebuilt 6 bolt block with a 5 speed manual trans. I haven't ever been able to keep watching it when it happens since im slowing down fast but every where else my LC1 shows perfect and consistent readings, 14.7 as close as it can and it gets rich to 10.-11 if I have the throttle down more. Im saving up for dsmlink but for now Im still getting used to evoscan, more figuring out how to keep it running in drive but so far I've used it to set TPS voltage and percentage, along with verifying the new 02 sensor is doing its job. unfortunately my current factory speedometer needle came badly uncalibrated from the P.O. but i'm using my gps for now, as soon as I can figure out whats keeping me from using evoscan in drive maybe I can compare the log.

have not tried the last thing really. as long as I let go from the clutch fast, that's how / when it cuts off. if I let off slowly it does not stall. but I should be able to let go fast..sometimes it almost dies but doent but that's slow stops.

for the last thing are you talking about first gear? isn't the engine speed higher then idle (700-900?) right before it stalls out in 1st?

 

[1995silvergst]

Ok I am asking a lot to diagnose and not guess so I apologize for the amount of questions.

And if you decelerate in gear letting the motor drag down to idle speed then push in the clutch what happens?

I mean any gear while in gear raise rpm up and let off throttle till RPM is around idle and push in the clutch.

Since this motor has been swapped when did you first notice it happening (after a part change) or are you a new owner?

Who performed the swap and have you checked the bellhousing bolts? loose bolts can cause binding in the drivetrain pretty bad.

You said (new o2) did you recently replace this? if so which front or rear? If the front is it plugged in to the correct socket? (cruise socket looks the same)

I am not familiar with Evoscan is there a selection for NLTS or no lift to shift? if so uncheck it.

Has the clutch been replaced recently? is it adjusted? does it need shimming?

Any throttle body work lately? is the throttle plate closing correctly?

Just throwing ideas out and trying to eliminate the possibilities BTW no CEL codes right?

 

[1Gina2G]

Ok I am asking a lot to diagnose and not guess so I apologize for the amount of questions.



I mean any gear while in gear raise rpm up and let off throttle till RPM is around idle and push in the clutch.

Since this motor has been swapped when did you first notice it happening (after a part change) or are you a new owner?

Who performed the swap and have you checked the bellhousing bolts? loose bolts can cause binding in the drivetrain pretty bad.

You said (new o2) did you recently replace this? if so which front or rear? If the front is it plugged in to the correct socket? (cruise socket looks the same)

I am not familiar with Evoscan is there a selection for NLTS or no lift to shift? if so uncheck it.

Has the clutch been replaced recently? is it adjusted? does it need shimming?

Any throttle body work lately? is the throttle plate closing correctly?

Just throwing ideas out and trying to eliminate the possibilities BTW no CEL codes right?

I did the swap myself and i just retightened then trans bolts but they weren't loose. I just got every thing to where i can actually drive so im just finding things out. With that said the front 02 sensor is in the 02 housing where it should be.

The clutch was replaced/ rebuilt a while ago when the transmission was getting rebuilt and is oem but with a new lightweight fidanza flywheel.

The TB is new/ rebuilt with working sensors. No CELs either even through evoscan.
No NLTS i believe in evoscan but even if there is i know it was never checked in.

 

[1Gina2G]

okay so ive done alot of work and driving since this threads been started and I think that the 'problem' may very well be 'normal' and may just be in my driving as crazy as it sounds.

not only is this my first DSM that i started off from scratch to where it is now, but my experience driving manual transmissions are minimal.

Like I was trying to explain, the car will shut off if you go from gear to neutral to slow down, rapidly slow down that is. Im trying to be super cautious with holding in the clutch pedal in so I thought i read it was best to go into neutral to slow down thinking you would otherwise need to hold the clutch in while braking in gear.

looking at multiple threads about various vehicles online(any vehicle), many people also notice there engines dieing upon disengaging to neutral at high or fast speeds. Seems to basicly be that your just not supposed to do this.

Almost always, if I just get to the top of a tall bridge, and drop into neutral the car will die after letting off the clutch, only time it dies without rapidly decelerating.

So what Ive noticed lately is that its perfectly fine to coast in 5th and brake in 5th at high speeds as long as speeds dont go to low, as crazy as that sounds. wondering if Im doing more harm by braking in gear with or without the clutch in though? otherwise thread resolved