RPMs drop real low, MIL flashes once. no codes.

[theKnifeArtist]

sometimes when i stomp on it and let go(at a lower speed usually), the RPMs drop lower than 1000. sometimes it even stalls. i thought this was a TPS sensor misadjustment because i had this problem before...and i had a tps code..so i readjusted and it fixed....
so i thought maybe a bumped it working on the car and had to readjust it..
i don't remember when this started but now its doing it again with the dropping of the RPMs..but now i see the light go on when they're really low, and then when it recovers it turns off. i checked for stored codes, but it reads a constant blink indicating clear.
whats going on?

 

[trydrew]

I would like to know as well, if anyone has any ideas.

 

[MDCmotorsports]

The code is due to the fact the car is running lower than 500rpms (iirc).

Sounds to me like you have a BOV venting to atmosphere or for some reason the car is running mad rich.

 

[theKnifeArtist]

that could be it..but i've had the bov for some time now and its just been acting up lately...i think its been happening after i did allot maintanance stuff on it including spark plugs fuel filter and a whole bunch of other stuff that wouldnt relate to that..

 

[trydrew]

My car just idles low and when you rev it and let off, it dips. I didnt notice a light though. I was gettin 51 but i replaced the tps and its gone, but it runs the same even after timing it right. Ive checked and rechecked for vacuum leaks and nothing :aigo: .
When the tps was intermittent, it would idle at 700 or so and it would catch the rpm drop like it should, but now it doesnt.

 

[theKnifeArtist]

you saying my TPS could be bad? wouldn't that give me a code?

 

[87_7MGTE]

MDC is right about the light, the light indicates crank mode (RPM < 400 or 500 rpm, cant remember which one)

 

[Boostedstr8six]

The code is due to the fact the car is running lower than 500rpms (iirc).

Sounds to me like you have a BOV venting to atmosphere or for some reason the car is running mad rich.

Motion seconded....

...the Ayes have it.

 

[Nick M]

If you stomp on it, it nearly stalls, and if you slowly push down the acclerator pedal it is fine?

 

[theKnifeArtist]

no no, when applying gas it is fine when upon release it will fall down down real low and sometimes stall.
and whats that your talking about boostedstr8six?

 

[Nick M]

Well, I think you have an idle problem. A simple check is the dashpot, which slowly closes the throttle upon deceleration. Its primary purpose is HC reduction, but with the ECU programmed to compensate for it, you can have a bad idle if it is not working right, as in a stall or low rpm.

 

[theKnifeArtist]

you know whats weird. i took it for a simple drive today and i was driving like normal and boosting a little and it ran fine! had mad compressor surge(gotta release that springs)but it ran fine. weird.

 

[johnathan1]

My NA used to do this, and it bugged the hell out of me...sold it, and never found out what the problem was.

 

[mattsplat72]

I am also having the same problem . It isn't the Tps because its brand new and I had a shop install and adjust it, also I replaced the Isc off of a running car. Timing is at 10btdc as per tsrm . I threw a code 31 a few times but not all the time . stock bov not venting at all checked every feasiable location for a vac leak and found nothing . Was just planning on getting a new Afm or switching to a lex/550 set up . But maybe we can figure out the cause of this mystery problem

 

[antman]

Motion seconded....

thirded!

 

[mattsplat72]

MDC is right about the light, the light indicates crank mode (RPM < 400 or 500 rpm, cant remember which one)

Would you be willing to drive down to Mt Vernon an give my car the once over. I feel that I am way over my head . Could most likly kick down some gas money for the effort:drink1:

 

[drbowser3]

With a BOV vented to the atmosphere, and still running an AFM, it will do that because the air is let out of the IC pipes, and the AFM sends excess fuel to the engine since it thinks a lot more air is flowing in, but in reality it just escapes out the BOV and never makes it to the engine. My car does this, solution= dont rev it, and when pulling to a light, let the RPMS drop to about 1500 before throwing in the clutch. In theory your confusing the car. AFM FTL

 

[theKnifeArtist]

yeah, mega rich mixture..
well i'm automatic by the way.

 

[drbowser3]

yeah, mega rich mixture..
well i'm automatic by the way.

Well then the whole clutch thing you can disregard, but the rest remians the same. If you rev it, and then feather the throttle back to idle it should be fine.

 

[theKnifeArtist]

yeah i've been doing that..
i dont really feel good giving in to this problem