Basically, whenever you aren't putting any sort of load on the engine (well, accelerative force I guess would be the best term for it, though I think I just made that up) you're going to start slowing down (unless you're going down a steep grade).

 

To clarify... Your actually getting no fuel to the engine when letting off the gas on a 5spd. Try something very interesting:

1-get up to speed... say 30mph (any gear)
2-let off on gas completely
3-turn off the car while coasting... yeah... actually turn it off... and see what happens
4-turn the car back on... (again... while your coasting) as in turn the key to ON (doesn't and will not let you crank)

Very important: All this is done while the car is in motion...

(This only works for a 5spd)


Kinda cool... works with any manual car ive tried...

 

LOL, I found out in a similar manner, but doing a late-night run on an empty highway, downhill, with a custom high-flow intake on my Altima. It was ingesting so much air it messed up the a/f ratio and just shut off... while I was still in gear coasting. I did what you said, just turned it off then back on and safely pulled over... all w/o a hitch.

 

Not all. Only the 1995 se and crimson blaze 1999 se-l's had them as a rocker switch on the wheel opposite the cruise control controls.

The 95 had it via hyperhumic constrabulator and the 99 via a flux capacitor.


























j/k

 

In D, OD on (4th gear usable).

So why do I feel like my car is 'engine braking'. Should I be worried?

 

i also advise pulling the key out...all the way to make this fully work!

 

LOL! Not a good idea....

 

Not a good idea at all. Pretty funny though.

 

what i totally thought that would help with the essence of the experiment...the experiment of uselessness...

 

just wait till the steering wheel lock and u hit a tree.

 

thats onlt on 5 spd

 

Well, you can only remove the key when it's in the Lock position, right? And that means steering is locked, for autos and 5sp.

Just make sure you're going absolutely straight, that's pretty easy with some caster built in.

 

huh? lock position, yeah you can take it out, but if its not in park (autotragics) the key wont go to lock. itll get stuck in there

 

Shift lever in neutral?

 

Not with the autos. The key lock cable is only released when the shift lever is in Park.

 

interesting, when i let off the throttle in my 5spd jeez it jerks a little then stabilizes itself as it slow down, of course it trys to hold revs at about 1000-1500 but it feels like i stepped on the brakes

LOL @ key out experiment

 

Oh, well ain't that something? Auto, ftl.


Crusher103: How's your engine mounts?

 

the mounts are fine, its like a sudden jerk from coming off of it, it happens slightly in 2nd and in no other gear. every MT car i have driven does the same thing

 

Is it more violent in lower gears?

It's either engine mounts (most likely on our older cars), or driveline slack.

 

Ive figured out the key out thing right after i bought the car, its really cool. But i have a question about the ECU cutting fuel. I know it cuts the fuel when you let off the gas, but at wat point does it start firing the injectors again? If I engine brake to like 5mph in first gear the car wont die itl cruise at a steady 5, or idle engine speed in whatever gear im in. So does it fire the injectors once the RPM gets towards the idle speed or before that or wat?

 

Yes, injectors resume normal duty around ~idle.

 

For some reason, I thought the Injectors keep firing, but just no fuel gets spit out. ?

edit: oh wait, i'm getting it mixed up... the sparks keep firing, but injectors don't, right?
Dr J

 

There's really no way to do that; if the injectors open, fuel gets released (unless the pump stops, but even then it'd take a while to purge all remaining fuel).

The IPW just drops extremely low, limiting fuel flow from the injector to a very small amount.

 

Well, I get back in town on Wednesday. I will probably run a compression test then. That is....if its warmer than -15 degrees or whatever it is in Denver right now....

 

I'd find a warmer parking garage and do your thing. Maybe an underground parking that's insulated.

 

I let the car warm up fully and drove it for 20 minutes or so, unplugged the fuel pump, took all spark plugs out, and cranked it on the starter with the throttle wide open until the readings leveled out.

Here they are in relation to where they are in the engine bay, going left to right looking at it from the front. Or passenger side to drivers side. The arrow points to the front of my car


V
V
V
V
V

4 ... 5..... 6
163 170 171


1... 2..... 3
160 159 168




It held the compression on all these as well, letting it sit 10-15 seconds still held the same pressure. They maybe dropped 1 psi at most.


How do these figures look?

 

Oh, one more thing to add, my car is definitely shutting off fuel because going down a hill in second gear I lifted my foot off the gas then shut off the ignition and there was absolutely no change in deceleration or engine note.

 

http://forums.maxima.org/7400-post2.html

142-185 psi.
max difference between highest and lowest is 14psi

you're good for now.

 

i found this thread using the search and hope to get answers here to my issue which seems relevant. When I'm braking and get to almost a complete stop my engine will just cut off. I'm not sure if it's the fuel being cut to the engine. i thought it might be an alternator battery issue but after replacing both this week it still did it yesterday. i have also had the fuel filter replaced. Could it be the injectors? i have over 300K miles on my car. Any help/suggestions are greatly appreciated. Thanx.

 

Clean your throttlebody and take apart your idle air control valve and clean everything. Make sure the air hose that feeds the IACV isn't crimped or anything either.

 

I was gonna say take it outta gear before you come to a complete stop... thought this thread was for 5sp peeps.
But yes, clean out the air intake tracks.

 

yep, My thoughts exactly. Get a compression test. Your problem may be there. Hopefully you don't have a bad compression or a bad Head gasket.