Im seeming to have an issue with this low idle/miss. Im having a hard time coming up with an answer to it. No codes! What are the symptoms for valve spring failures on a hemi? If they do fail what all is involved in trying to repair...ie. replace just the spring, or rocker arm/valve also?

 

a mechanic's stethoscope
{or an even better electronic stethoscope}
can help find the noise that 'almost always'
will come from a broken valve spring
if you wish to narrow down which valve cover should be removed

http://www2.northerntool.com/auto-re...tem-160875.htm

there are flexible 'boroscopes' with lights
that can go in through either the oil cap, PCV, or breather openings
to look for broken valve springs

http://www.tooldiscounter.com/ItemDi...le&kw=SLIPV300

for a low idle miss
my first suspicion would not be a broken valve spring
but either a burned valve or bent valve

an air leak down tester
or a 'dynamic' or running compression test
can spot the cylinder of these maladies

http://www.area51groupllc.com/index....276cb2a7715865

http://misterfixit.com/dyncompr.htm

perhaps the first thing to try for a miss at idle
is to pour a bottle of FI cleaner
like Chevron Techron or official Chrysler FI
into the next two half tank partial fills of gasoline

good luck

 

Broken/bad springs usually manifest their problem at high rpm long before effecting the idle.

 

great information...the weird thing is sometimes it will drop down to a 500 rpm idle and miss, and then other times it will idle at 750rpms and idle. I dont understand why the idle speed will sometimes be low, and other times be high. The truck runs pretty strong, it doesnt seem to have any issues at the higher rpms. Im running a bottle of lucas FI cleaner through the tank right now.

 

truck seems to run great at high rpms.

Whats odd is I never had an issue till I changed the plugs/wires. I double checked everything. gaps were all ok, and wiring was right.

 

Bad plug or wire??

 

how do you check if you have a bad plug or wire, or better yet a coil pack?

 

Ohm meter. I do not have the specs though. A compression check wouldn't hurt either.

 

an EGR valve that is malfunctioning
or
a partially plugged fuel injector
should be considered
when trying to eliminate idle speed misses

the dual spark plugs in each cylinder of the 5.7 hemi
greatly reduce the possibility of poor ignition
as a cause of idle speed misses

even if the miss is not ignition related
an inexpensive meter like this now discontinued one:

http://www.etoolcart.com/sparktesterkeq2969.aspx

by its
'burn time'
and
'peak KV' readings
can identify which cylinder is missing

the expensive SnapOn Vantage meter
with Secondary Ignition Voltage adapter can do this too
as can many older ignition diagnostic meters

 

I have read some people say that the 03's do not have a EGR valve. I need to check and see if mine does. How do you tell if a fuel injector is going out or is out?