well its been there for a while but barely noticeable. now its getting bad. ill be sitting at a light with it in gear at idle and the rpms will drop like 2-300 to the point it seems like its gonna shut off and all the dash lights dim then as quickly as the stumble came it goes away but it happens like every 10 seconds. i was thinking of replacing my idle control motor first. just want to get some more ideas on what would cause it. would the intake leak cause it? Thanks fellas.......

 

I would say to get the car scanned before you start throwing parts at it. That way you would at least have some sort of idea what it is.

 

i have a scanner, It has no codes everything seems to be ok in real time analyzing. the car runs great over 1100 rpm. the iac motor wont throw a code if its not working properly that is why im thinking its a good possibility of that being the probem. but i wanted to get other ideas on what would cause the stumble.

 

I had the same problem. It ended up being a couple different things. The main problem was IAC valve. The spintle on mine was actually broken. Sometimes they can get deposits on them, so you will have to take it off and apart to clean it. Your car isn't getting enough or too much air.

Also check for burnt plug wires and check your fuel injectors. A couple of them might be clogged or malfunctioning. Get an ohm meter and ohm them out to see if they are operating within specs.

IAC was under $100 and an easy fix.

Hope this helps
Finch

 

What are the IAC counts? At idle they should be about 40 give or take. If they are off, you could have a vacuum leak.

Check the pintle like finch said and check your EGR also.

 

ok heres what i got from scanning it:

idle rpm in park 700-/+
idle rpm in gear brake on 600-/+

battery voltage in park idle 13.2
in gear brake on 12.5
iac counts in park @ idle 68-70
iac counts in gear @ idle 58-63

when stumble occurs iac counts do not change
battery voltage drops from 12.5 to 11.8 at idle in gear
engine vacuum is 19inches
and the egr valve is blocked off and line is plugged

beats me wth is going on here......

 

I have the same problem only I have hesitation problems and backfiring. I am taking it in tomorrow. I am pissed off at my damn car!!!

 

one idea would be to get a new fuel filter, easy and cheap. also go for getting your injectors cleaned.

 

Ok with all the **** yall say yall cars are doing mine did the same thing and it was my damn opti spark on its way to going out and youll never no when it will but i would say check that cause thats what mine did before it got real bad to were i could be driving down the road and my car just would backfire and then sometimes it would just go dead all the power would just go out why i was driving as if someone unhooked my battery why i was driving just check it ye it will cost you but now that i fixed mine my car is fine.

 

There you go, if the battery is good and the connections are clean (check them all and don't forget the grounds at the engine and frame) Then your alternator is shot. However, Check the voltage across the battery while reving the engine up to about 1K rpms. It may be from running too slow.

Battery voltage when the car is running should be closer to 14 volts.

I would fix that problem first cause chances are good that is your entire problem right there.

 

Check your voltage at the Battery using a Digital multi Meter. My scanner reports my voltage exactly as yours however when I measured the voltage at the battery I discovered that its 1 volt more than any reading I get from the scanner.

If my scanner says 12.5 then the battery voltage is 13.5Volts. I contacted AutoXray support and this is the response I received from their tech man..

Marvin,

The 1995 Camaro is a bit of a hy-brid vehicle being partially OBD-I and
OBD-II.
The clear code function may not perform correctly on this vehicle.
May I suggest disconnecting the vehicles negative battery cable for 10
min.
to clear the PCMs KAM.

As far as available voltage, this data comes from PCM, which it
receives
from various inputs and then reports that data over the data bus line
to a
scan tool. The voltage the PCM sees may differ from available voltage
at
power distribution points. The key here is that during diagnostic
procedures
the amount of available voltage must be at least 10.5v when measured at
the
pin on the PCM with a DVOM.

Keep in mind data received on a scan tool is a reflection of the RAW
data a
PCM is receiving and converting to usable data.
Some of the data you may see during KOEO is the last known retained
values
of the PCM (inferred) as in the case of RPM. Where as the last known
min.
value of engine RPM may have been 50 RPMs so as when you request data
from
the PCM during KOEO it may indeed report this last known value,
obviously
when the engine is started this data is updated and the PCM can then
begin
reporting actual data via input sensors.
I hope this helps in your quest of understanding OBD data and
functionality.

Len Mitchell
Technical Support Manager
AutoXray , Inc.



Now you see why I am asking you to read the voltage at the Battery. My scanner always report one volt below batteries voltage.

Marvin