95 T-brd Running Bad - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

EGULL · 08-10-2010, 15:59

OK IT'S 4.6L BOUGHT IT AND EVERYTHING WAS FINE UNTIL DRIVING IT HOME THE ALTERNATOR WENT OUT. PUT ON A NEW ONE AND WHILE DRIVING IT HOME THE CHECK ENGINE CAME ON. TOOK TO A.ZONE ON THE PRINT OUT THEY GAVE ME IS-TROUBLE SHOOTING P0300 THEN DEFINITION CYCLINDER MISFIRE-RANDOM CYCLINDERS. THEN EXPLANATION: THE POWERTRAIN CONTROL MODULLE MONITORS THE CRANKSHAFTSPEED AND HAS DETECTED A MISFIRE THE CONDITION: PROABLE CAUSE #1 IGNIION SYSTEM FAULT-SPARK PLUG(S), IGNITION WIRE,COIL #2 VACCUM LEAK, #3 INJECTOR FAULT, #4 LOW OR HIGH FUEL PRESSURE. PUT ON NEW PLUGS ENGINE LIGHT WENT OFF, WIFE DROVE AND HEARD A POP (I WASN'T WITH HER SO THATS ALL I KNOW) ENGINE LIGHT CAME ON. BEFORE I COULD DO A CHECK KEPT DRIVING IT AND NOW THE ENGINE LIGHT IS OFF!! HERE'S THE PROBLEM: IDLES FINE IN PARK-AROUND 1K WITH A/C ON, IDLES LIKE CRAP IN DRIVE!! I NOTICED WHEN I GIVE IT GAS WHILE IN PARK IT HESITATES (BOGS DOWN) OR WHEN DRIVING. HAPPENS EITHER COLD OR HOT. RUNS A LITTLE BETTER WHEN COLD. OH YA DROPS TO 400-500 RPM IN GEAR IDLEING.

ANY IDEAS OF WHAT TO CHECK OR REPLACE 1ST?
I WAS TOLD BY A SO CALLED MECHANIC FRIEND OF MINE TO PULL THE PLUG WIRES 1 AT A TIME AND SEE IF THAT CHANGES THE WAY IT RUNS- IF IT DOES WIRE GOOD, IF NO EFFECT WIRE BAD. DOES THAT WORK?

LET ME KNOW WHAT I SHOULD DO!!!
HOTTER THAN HELL HERE IN ST LOUIS

THANKS FOR THE HELP

EGULL · 08-10-2010, 16:01

Forgot To Say I Have Read The Other Threads On The Idleinf Issue

KStromberg · 08-10-2010, 16:32

Technical Description

Random/Multiple Cylinder Misfire Detected
What does that mean?

Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
A P0300 OBD code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are misfiring, nor why.

Symptoms may include:

the engine may be harder to start
the engine may stumble / stumble, and/or hesitate
other symptoms may also be present

Causes

A code P0300 may mean that one or more of the following has happened:

Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.