okay i'm working on a 2005 neon complaint is a check engine light misfire code entering the engine t k25 go to codes see i got a 301 sonar number one misfire go to my data display let's look at some data look at some fuel trims things like that and you can see they got a negative 17 percent long-term fuel trim and a negative five short term so just something to keep in the back of our minds right now that this thing's running a little bit rich computer's taking the fuel away even though we don't have a trouble code for that okay so exit out of here we go to our functional tests system tests sorry we can look at our misfire counters and we can look at what's going on and you can see that it's cylinder number two interestingly enough there we go there's an indication on number one number two showing a little bit too not a severe miss sitting here in the car i can feel a little bit rough let's go into the hood now and take a look all right so i got a couple capacitive pickups on cylinders one and two i want to look at them on my scope so again looking at our sparkline firing lines on the ignition and if you look close at this one you're going to see when i snap it there's a lot a lot of shortening of this sparkline this cylinder right there was a good capture of it and so that's the bad one let me switch cylinders here so i'm changing my trigger display to do there's a good cylinder that looks great now here's the thing what i didn't tell you yet is i moved the plugs i switched to number one plug to the number two cylinder and that crappy pattern moved with the plug so we'll get a bad plug so when i pulled the plug out it was black and i said i said uh you know this car having a recent tune-up is it possible that we got a bad plug and of course it is but this was the problem initially as well runs good for a while then we get a misfire back so let's let's think back to our fuel trim for a second and a misfire with a bad spark plug is not going to give you a negative fuel trim number so my concern is that maybe this number one fuel injector could be leaking which made the plug black followed it out messed up my spark lines and so what i need to do is an injector balance test i'm going to do that i've already adapted a pressure gauge as a fuel rail i'm going to connect up my gauge to it it's in series to the rail take my ignition leads off and i brought out my injector balance tester little timer tool you see the settings on it it's got one pulse 10 pulses 100 pulses sorry 50 pulse in the middle that's where i'm set at so i'm going to unplug these fuel injectors we're going to do a flow test balance test we're gonna do them all because we want to make sure that we don't have any other problems with the other injectors i'm going to go back in the car let me grab my scan tool turn the key on take the scanner what i'm going to do is i'm going to use a bi-directional mode also known as functional test a lot of glare on the screen so i'm going to go functional tests and i'm going to go atm test and i'm going to scroll down and i'm going to find my fuel pump and i'm gonna hit yes and then i can turn my fuel pump on on so you watch my pressure gauge hit yes yes again to turn it off you see i'm at around 57 psi rest pressure so now i'm going to take my timer tool plug it into the injector problem is it's the wrong style plug that's okay we can be a little creative you got to be careful with this we don't want our t-pins touching each other i'm gonna use some t-pins and uh i'm gonna adapt to this i need a third hand here so what this timer tool is going to do is we're going to apply a power and a ground to those two pins on the fuel injector all right so i got my jumper wires in here being real careful that they don't touch each other and i got my jumper wires on my timer tool set on a 50 pulse i'm going to re-energize my fuel pump again again using the scan tool and you'll watch the gauge see the gauge move turn the pump off rest pressure 57 press the button on the timer tool and i'm going to watch my fuel pressure drop you see we dropped down to about 27 28 psi from 57. we'll do that one more time re-energize a fuel pump 57 is my rest pressure hit the timer button again and we drop down to about 27 psi you don't want to do that more than two times without tr cranking the engine over because we'll end up flooding the cylinder out and could hydro lock the motor that'd be real bad so i'm gonna move to the next injector just move my two jumper wires again being careful they don't touch each other so i'm now on the number two injector re-pressurized 57 is my rest pressure i'm gonna hit the button we dropped to about 34 psi one more time re-pressurize 57 my starting point to cook about 33 psi so confirmed problem here number one fuel injector definitely leaking fouled out the spark plug gave me a bad pattern on the plug had i rushed the car i would have just put a plug in this thing but looking at the fuel chain numbers being negative 17 that's what put me in this direction so let's make sure that we have good injectors across the board that was dropping to 33 34 on that number two number one is the suspect i'm now on the number three re-pressurize the system hit my timer button 33 34 psi just like the number two unlike the number one dropping down to 27 about a five or six psi difference re-pressurize them now on the number four re-pressurize the system press the button 33. we need a number one fuel injector that's it i'll take care of it