Home | Contact Us | FAQ | Search & Site Map | Link to Us
Sign In | Join | Other 45 Sites in Network
HomeAnnouncements
Discussion Groups
By Brand
BMWChevroletDodgeFordGMHondaLexusMercedes-BenzNissanPeugeotToyotaVolkswagenOther Brands
By Topic
4x4 CarsRVsDrivingMaintenance & RepairCar AudioCollectible Cars
Country Specific
Australian ForumsUK Forums
ArticlesAuto InsuranceBuyingCars & TechnologyMaintenanceMiscellaneousSafety
DMV Resources
Related Topics
MotorcyclesBoatsMore Topics ...

Car Forum / Dodge / Dodge Trucks / February 2008

Tip: Looking for answers? Try searching our database.

'96 RAM 1500 5.9L SLT 4x4 suddenly won't idle this week.

Thread view: 
Enable EMail Alerts  Start New Thread
Thread rating: 
Dang ol' Boomhauer - 10 Feb 2008 15:23 GMT
Truck is stock with 110K miles.
Wed-Fri it wouldn't idle until completely warmed up.  It just stalls as RPMs
go to zero unless you keep your foot on the gas a little.  Drove fine when
warm.
Sat it had same problem several times even after warmed up.

It's always run great other than this happening now.

Any ideas, anyone?  EFI doesn't have a choke that could fail, does it?

Any help would be greatly appreciated.
Denny - 10 Feb 2008 18:26 GMT
> Truck is stock with 110K miles.
> Wed-Fri it wouldn't idle until completely warmed up.  It just stalls as
[quoted text clipped - 7 lines]
>
> Any help would be greatly appreciated.

As dumb as it sounds, have your battery tested. That's a classic symptom of
a battery starting to loose it.

Denny
Tom Lawrence - 10 Feb 2008 20:12 GMT
> As dumb as it sounds, have your battery tested. That's a classic symptom
> of a battery starting to loose it.

I doubt highly it's his battery hold-down, Denny...  and even if the battery
wasn't tight, it wouldn't cause the erratic idling.

On the other hand, if the battery were "LOSING" it's ability to hold a
charge, well...  then you may be on to something!

:^)
Denny - 10 Feb 2008 20:39 GMT
>> As dumb as it sounds, have your battery tested. That's a classic symptom
>> of a battery starting to loose it.
>
> I doubt highly it's his battery hold-down, Denny...  and even if the
> battery wasn't tight, it wouldn't cause the erratic idling.

It could be. If the battery was rattling around all the little volts inside
it get scrambled up and forget which way they were headed and after they're
good and lost the engine don't run right..    <BG>

Denny

> On the other hand, if the battery were "LOSING" it's ability to hold a
> charge, well...  then you may be on to something!
>
> :^)
Dang ol' Boomhauer - 11 Feb 2008 03:27 GMT
>>> As dumb as it sounds, have your battery tested. That's a classic symptom
>>> of a battery starting to loose it.
[quoted text clipped - 12 lines]
>>
>> :^)

You know, I halfway wondered about that.  About a month or two ago when it
was colder, I noticed a hesitation once or twice when cranking on cold
mornings.  I'll check the battery...  Thanks everyone!
PeterD - 10 Feb 2008 21:01 GMT
>Truck is stock with 110K miles.
>Wed-Fri it wouldn't idle until completely warmed up.  It just stalls as RPMs
[quoted text clipped - 7 lines]
>
>Any help would be greatly appreciated.

In addition to Denny's battery suggestion I'm going to suggest a can
(or two) of Techron injector cleaner. I've seen that stuff clean up
some really odd idle problems around here.
Tom Lawrence - 11 Feb 2008 01:51 GMT
> In addition to Denny's battery suggestion I'm going to suggest a can
> (or two) of Techron injector cleaner. I've seen that stuff clean up
> some really odd idle problems around here.

Couldn't hurt...  but the fact that the engine holds idle when slight
accelerator pressure is applied indicates that the idle air control motor
isn't allowing enough bypass air around the throttle plates, due to the lack
of voltage from the battery, and thus requiring the throttle to be opened up
slightly to allow the proper amount of air into the intake.

For the OP's benefit...  your question about a failing choke isn't far off
the mark... in the EFI world, there's no "choke" specifically, but there is
an Idle Air Control motor...  this is a little stepper motor on the throttle
body that drives a pintle back and forth, and regulates the amount of idle
air that's allows to pass around the throttle plates, so that even with the
throttle closed off, the engine gets enough air to idle.  That IAC motor is
controlled (as is everything else) by the computer.  However, the computer
is very sensitive to voltage...  give it too little voltage, and strange
things begin to happen...  one of them is it's inability to properly
position the IAC motor, thus preventing enough air from getting into the
intake.

Step one is to load test the battery, and exchange it if it won't hold a
proper charge.  Step two is to remove the IAC motor from the throttle body
(I believe it's on the back side, closest to the firewall), held in with a
couple of Torx screws.  While holding the motor, with the electrical still
connected, switch on the ignition.  If operating properly, you should see
the pintle fully retract, then fully extend, then settle somewhere in the
middle of it's travel.  It should operate nice and smooth.  If you notice
any stuttering, or if it looks really fouled up with carbon and such,
disconnect it from the electrical line, and soak the pintle end in some carb
cleaner.  If it still doesn't operate correctly, it's time for a new one.

While you're there, it wouldn't hurt to give the throttle body itself a good
cleaning...  unlike a carburetor, your throttle body is "dry" - only air
passes through it...  no fuel to help wash away crud.  Over time, you get
some nasty build-up around the throttle plates.  Throttle body cleaner in a
spray can works, but I prefer the type of cleaner that comes with foam swabs
(they look like marshmellows) that you soak in cleaning fluid and hook onto
the end of an applicator.  That lets you really swab out the inside of the
throttle body, and I think it does a better job of cleaning.
Bob  AZ - 11 Feb 2008 04:14 GMT
That lets you really swab out the inside of the
> throttle body, and I think it does a better job of cleaning.

Tom

Cleaning the throttle body says to me, that one cleans out the
interior of the throttle body. So how do you gain access to the
interior of the throttle body? I have a 2001 Chrysler LHS and a 2001
Dodge V8 PU.

Thanks
Bob  AZ
Tom Lawrence - 11 Feb 2008 06:07 GMT
> Cleaning the throttle body says to me, that one cleans out the
> interior of the throttle body. So how do you gain access to the
> interior of the throttle body? I have a 2001 Chrysler LHS and a 2001
> Dodge V8 PU.

http://www.run-rite.com/industry/9710.html
nunya - 11 Feb 2008 13:37 GMT
> That lets you really swab out the inside of the
>> throttle body, and I think it does a better job of cleaning.
[quoted text clipped - 8 lines]
> Thanks
> Bob  AZ

here is the product i like.  it is made by 3M and does a fantastic job
without having to dig around in you fuel system with a spoon.

http://tinyurl.com/35s5tl

it requires a specific hose and regulator kit that isn't cheap but the money
saved by doing the job yourself will make up for the
hose/regulator/canhanger.

http://tinyurl.com/2ru38l

you inject the cleaner while the vehicle is running and it will smoke like a
freight train so don't be up wind of a gripy neighbor when you decide to
give it a whirl.  my trucks will start getting a rough idle about every 80k
and i'll pull out the air cleaner and clean it.  then i run the 3M system
and i am good to go for another 80+k.

we have our own fuel tank and only stock premium fuel but if i end up having
to buy fuel out in the wild and get a bad load i feel it immediately.  when
this happens i load the fuel up with isopropal alcohol and after a couple of
clean tanks i run the injector cleaner.  this is one instance where the ol
"mechanic in a can" is a good thing.
michael
S. A. King - 11 Feb 2008 16:08 GMT
Had a '94 5.2 that did this. Would clear up after a day or two and run
fine for a month or so. Finally got a check engine light, turned out to
be O2 sensor.
Si

> Truck is stock with 110K miles.
> Wed-Fri it wouldn't idle until completely warmed up.  It just stalls as RPMs
[quoted text clipped - 7 lines]
>
> Any help would be greatly appreciated.
curmudgeon - 11 Feb 2008 17:22 GMT
EGR valve stuck with carbon.  Ruins idle. exact symptoms you describe.

Remove and replace or you can try cleaning...

> Truck is stock with 110K miles.
> Wed-Fri it wouldn't idle until completely warmed up.  It just stalls as
[quoted text clipped - 7 lines]
>
> Any help would be greatly appreciated.
 
Sign In
Join
My Latest Posts
My Monitored Threads
My Blog
My Photo Gallery
My Profile
My Homepage

Start New Thread
Enable EMail Alerts
Rate this Thread



©2008 Advenet LLC   Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.