Hey guys, this time is for real now.........I have been experiencing some very strange things from my car

the symptoms are as follow: while driving at about 70-80 mph.......if I put the car in neutral, the tach will fall below 1k rpm, try to come up, swing violently between 1k and 250 rpm and then the engine would die.........

I have no clue what this could be, I have all recalls done, car has 8k miles on it
I have a midpipe......I don't think that can cause the problem
my compression is good (so the dealer says)
can this be related to my coils failing? (I have white spots on the bottom of 2 of the coils)
I haven't checked the spark plugs yet

again, this only happens if I am above 70mph THEN switch to neutral, I checked all my vacuum lines to see if they're loose

is this a serious issue?

this doesn't have anything to do with nitrous since it happens with our without nitrous spray.........

thankyou

 

I would go with coils first - then plugs - then fuel filter and pump.

No CEL?

 

I have a CEL but it is for the midpipe though.....or so I think, I will get a scanner tomorrow to see what is going on

I already ordered new coils, plugs and plug wires from mazport and it should be here soon

can there be a problem with the fuel filter and pump?!?!?

 

oh, and here are some more information to try and narrow this down

this only happens sometimes, it doesn't happen all the time

every time it happens it happens after about 10-15 minutes of driving HARD
then putting the car in neutral (I usually do it to get off the highway)

if I was babying her and do it, she will act fine

 

Could be - think linearly - if your spark is bad - it will die.

If there is low/no fuel going to the engine (esp at idle or generally when the throttle plate is closed) - It will die.

Those are the simplest ones - things get more complicated from there. Scan Reader is the way to go (should have got one at the same time as the midpipe -tsk tsk tsk). Then the guesswork is more limited.

Also the NO2 may have caused a lean condidtion - IE blown your engine if something bad happened while spraying... let's hope that is not the case.

 

i am going to post something about the similar thing that has happened to me, but without the nos.. waiting for the mpg results of my tank of gas to see if all is normal again...

in this order check...

plugs, make sure they are tight.
plugs, make sure they are not fouled.
wires, make sure they are tight.
coils, well if the above are not it, there is your sign.

beers

 

Why are you putting it in neutral after running hard, and while still at 70+ mph?

Ken

 

If a manual car is decelerating - with the throttle shut - the injectors go to zero, no fuel, to prevent backfires in the muffler. I'm not sure if the same would apply to an Auto, but there is a simple solution; don't do it anymore......

S

(Doctor, it hurts when I put my arm like THIS!
.........Well don't do it.)

 

I'm with Ken, why the hell are putting your car in neutral at 70mph?

Does it happen any other time you're in neutral at any speed?

 

What RPM are you putting your car in neutral at?

 

Yes the Auto does it also. Watched it on my MAZDA techs laptop. No fuel car dies.
It does decell mode then it figures out that it's idling and then it sees that the car is rolling. I think it just gets confused.

 

Check your oil and see if there is a pearly white buildup on the indicator . Ive been having similar problems with my car except my engine will sometimes dip to 250 rpm and die after 10-15 min of driving when i stop at an intersection. Wondering if they are related?

 

+2

stop doing it and your problem will go away !!!!

 

But that's not the point. An engine should not stall under zero load condition, period. It doesn't matter if his car is flying off the edge of a cliff when he put it in neutral.

 

I put my car in neutral when I wanna let the car just roll to a stop, as I have stated before, mostly while exiting highways

I have a manual stealth, but ok, I won't do it anymore

hope its just the coils or plugs, it would suck if my engine is dying........but the compression checked out ok and all and the car runs great apart from this particular crap

 

btw, my car never died at stops and never even like, died in any other case even once apart from this scenario

no pearly white mist in my engine oil, although I think it is time to change the oil since its 4k already but waiting for idemitsu........

my plugs shouldn't have gone that fast no? my car has only 8k miles..........

 

Probably a failing neutral switch on the tranny.

 

I had a similar problem on my Stealth when exiting highways. It ended up being some electronic choke failing. There were entries in the computer for it though. If you ride the clutch to the light does the issue stop?

 

no, it doesn't I have no clue wtf is going on, my friend had the same problem with his rb26 s13, he changed the ecu map and it went away...........so I decided to reset my ecu and the problem went away for now..............

 

Put the second screen back into your intake...

Something about heat and certain RX's needing the second screen on a highway...

Easy enough test...

Also...remove the engine cover...and weather stripping from the hood...and straighten out your cooling fins if they are trashed...

 

I have an hks reloaded intake......

remove engine cover? weather stripping? wtf?

 

ok...put back in your stock intake...and retest...

engine cover...RTFM if you do not know what it is...remove it...

the strip in the back of the bay that seals against the hood...there is a DIY...search it...

wtf...your face...

 

yes I remember some guy having a similar problem after taking screens out .....

 

weird, i put in neutral when ever i exit the highway or come to a stoplight and etc. and that never happens. oh well, knock on wood

 

I know what it is damn it, but what does it have to do with this?

btw I'm going to make my own intake soon anyways so ok

I reset the ecu and the problem seems to be gone at the moment........