2003 misfire
06-17-2017, 06:44 PM
#1
Thread Starter
Join Date: Jun 2017
Location: Texas
Posts: 1
2003 misfire
I have a 2003 Ford Mustang , I had bought it originally a year ago and it would overheat and cut off. I replaced thermostat and cooling fam system which fixed the problem, but led to another. Now my mustang will misfire I can typically drive it for about 10 minutes (if I'm not going over 2000 rpm) before it begins to misfire again. I've replaced the coil pack, the spark plugs and all the wires. No check engine light currently but not to long ago I pulled codes for cylinder 1 and 4 misfire, I've taken it to multiple mechanic shops and all of them are oblivious to American cars any help?
06-22-2017, 05:23 PM
#2
Join Date: May 2017
Location: ok
Posts: 20
have the following done:
start your car and take the longest flathead screwdriver you can find and stick the metal part right up against the fuel injectors of the cylinders with the suspected misfire. you should hear a clicking sound indicating that the fuel injector is firing off. if its not, further investigate the possible dead injector and get it replaced if needed.
Second, if your fuel injectors all come back as working ok, have a compression test done on the cylinders and make sure you are getting good compression. if the compression is low, you might possibly have a bent valve and its not closing all the way causing an air leak. hence the loss of power on the compression stroke. to perform this test, pull your spark plugs on the cylinders with the misfire and screw in a compression gauge. then crank your engine, a few rotations without starting it and observe your readings, you can rent this tool at any parts store.
if you are not getting compression consistantly in all of your cylinders, you might be looking at a tear down and rebuild of your valves.
If any of this is over your head, ask a mechanic to do the following on your car:
-A compression check
-A leak down test if the compression comes back low
-A test of your fuel injectors, if you dont feel comfortable doing that.
-last but not least, verify that your car has the proper ignition timing.
Hope this gets you started and good luck.
start your car and take the longest flathead screwdriver you can find and stick the metal part right up against the fuel injectors of the cylinders with the suspected misfire. you should hear a clicking sound indicating that the fuel injector is firing off. if its not, further investigate the possible dead injector and get it replaced if needed.
Second, if your fuel injectors all come back as working ok, have a compression test done on the cylinders and make sure you are getting good compression. if the compression is low, you might possibly have a bent valve and its not closing all the way causing an air leak. hence the loss of power on the compression stroke. to perform this test, pull your spark plugs on the cylinders with the misfire and screw in a compression gauge. then crank your engine, a few rotations without starting it and observe your readings, you can rent this tool at any parts store.
if you are not getting compression consistantly in all of your cylinders, you might be looking at a tear down and rebuild of your valves.
If any of this is over your head, ask a mechanic to do the following on your car:
-A compression check
-A leak down test if the compression comes back low
-A test of your fuel injectors, if you dont feel comfortable doing that.
-last but not least, verify that your car has the proper ignition timing.
Hope this gets you started and good luck.