Hey guys I was wondering if anyone would have any ideas for this. I
have a sporadic rough idle that usually occurs after a warm restart
(usually after the engine has cooled down for about 45 minutes or so,
and then started back up). But the other day it did it from a cold
start. The magnums have a rough idle to begin with, but this is way
more. When it happens the idle will get VERY rough and labored, I guess
a way to describe it would be that is sounds almost like it has a full
race cam. It will make a loud sucking sound in the throttle body (I
believe this is the AIS motor opening all the way up to keep the engine
from dying, but not sure) After 20 - 45 seconds it will clear up like
someone turned a switch off and idle perfectly normal. Now if you try
to drive it during one of these rough idle episodes it will hesitate,
surge, and sometimes even backfire (through the throtle body) then after
that everythings fine.
To date these items have been replaced to try and correct this:
new AIS motor
new EGR valve
new O2 sensor
cleaned the throttle body (thouroghly cleaned it inside and out)
new throttle body gasket
new fuel filter
new plug wires
new cap and rotor
new plugs
couple dozen bottles of fuel injector cleaner
switched back to stock computer, still did it
No trouble codes
I have run out of ideas of what it could be. Right now I'm thinking it
may be an injector sticking open, or maybe even a valve sticking, but I
really have no clue. Any ideas on what might cause something like
this. Fuel pump? Intake leak? After it clears up, it runs as good as
the day I drove it off the dealers lot, so I don't think it could be
anything major (at least I hope not). Seems to me to be something
electronic, but what?? Any help greatly appreciated on this. The
dealer will be the last step, but I'm sure they will blame my bolt-ons
for the problem. Oh yeah, it did this once before with stock exhaust
manifolds, so headers are not it....
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Michael Clark mike@snakebite.com
'93 MarkIII 4X2 V-8 SWB RC auto, DDBC
K&N FIPK, Flowmaster cat-back dual, MP SBEC
Doug Thorley Headers, Moroso Blue Max wires
180 degree thermostat, WaterWetter, Brass cap & rotor
one and only 1/4 mile time of 15.08 @ 90.82
My Dakota page=> http://userv.wt.net/~mclark/dakota.html
Dakota Webring=> http://userv.wt.net/~mclark/webring/ring.html
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