- This topic has 17 replies, 5 voices, and was last updated 9 years, 1 month ago by
.
-
Topic
-
car: 2003 Ford Falcon BA “VCT” ( australian make) 170Kms on the odo.
story: few days back i almost floored the accelerator pedal just needed to overtake a car. however car was running good after that. next morning misfire started. checked all the coil one by one, checked injectors one by one. replaced plugs with old used ones. got no code. no vacuum leak i sprayed wd40 all over the place can think of. cant find the problem. misfiring when idling misfiring on drive, misfire even worse when going uphill. please share ur ideas.
-
Replies
-
It may be fuel related. If you have a fuel filter try changing it. More in this link.
http://www.ericthecarguy.com/faq/solving-automotive-performance-issues
As cheap as spark plugs are you should put a new set in first. how did you test the coils. sounds to me like an ignition misfire. Is the check engine light on? might check for codes for a direction.
I checked the coiil by taking off one by one while engine running. No check engine light on. I believe it’s random misfire. My plan is now to change the fuel filter as I was putting cheap e10 fuel from random places. I started putting 98 and getting a bit better. But still missfires. Thing is missfires always on but sometime better sometime worse. My boss from my workshop says change the whole set of plugs and coils. But that’s gonna cost a bit. I just need to make sure because I don’t like throwing parts just like that.
If the coils are easy to get to disconnect the electrical connector at the coils one at a time and listen for a change in the engine. if it doesn’t change you know that is your misfiring cylinder. If you don’t want to throw a lot of money in it right away. just get you some spark plugs and throw them in your gonna need them anyway most likely and change the fuel filter and o from there.
okay i checked coil and plugs like 1000 times now. injectors too. getting a code P0505 IAC circuit fault. but no engine light on. could this be a reason for misfire?
Possibly but probably not. Did you change the fuel filter? Does it misfire all the time. Reading your original post it sounds like it does.
[quote=”ArmedsouthernEr” post=154314]Possibly but probably not. Did you change the fuel filter? Does it misfire all the time. Reading your original post it sounds like it does.[/quote]
yes i have replaced the fuel filter. and it misfires all the time. misfires a lot under load. swapping coils did improve a bit. improved as in i can drive around. now i am thinking coils. maybe they are week. when checking coils if i pull out (its a 6cyl) dont see any changes in rpm but i get the spark. i have replaced spark plugs as well. they all new. any idea how can check for week coil over plugs?
Ok you said its coil over plug. Disconnect the electrical connector to the coils one at a time and listen for an rpm change. If you get a cylinder that does not change then that is your misfiring cylinder. Swap that coil around to another cylinder and redo the test. if the misfire follows the coil you moved then that coil is bad. you could also have a mechanical condition with the engine that can cause low compression and cause misfires. Lets eliminate the coils first. they are one of the most common issues for misfires.
[quote=”ArmedsouthernEr” post=154369]Ok you said its coil over plug. Disconnect the electrical connector to the coils one at a time and listen for an rpm change. If you get a cylinder that does not change then that is your misfiring cylinder. Swap that coil around to another cylinder and redo the test. if the misfire follows the coil you moved then that coil is bad. you could also have a mechanical condition with the engine that can cause low compression and cause misfires. Lets eliminate the coils first. they are one of the most common issues for misfires.[/quote]
did as you said. what actually happening is random misfire. not the same cylinder misfiring.
I guess maybe I misunderstood what you were saying or were not on the same page. I asked you if it was missing all the time and you said it was. Sounded like you have a dead cylinder. Maybe we should step back and relook at it. Have you checked fuel pressure? Do you have a scan tool that can look at live data to see what your fuel trims are? Those two things should give you a direction.
[quote=”ArmedsouthernEr” post=154404]I guess maybe I misunderstood what you were saying or were not on the same page. I asked you if it was missing all the time and you said it was. Sounded like you have a dead cylinder. Maybe we should step back and relook at it. Have you checked fuel pressure? Do you have a scan tool that can look at live data to see what your fuel trims are? Those two things should give you a direction.[/quote]
PROBLEM FIXED. it was coil # 6. i was getting the spark but probably weak.after hours of checking in different rpm found the culprit. very happy.
thanks for all the directions you were showing. the scanner i had was not showing any code. my boss had a good one and hooked up once. it was showing injector # 2 malfunctioning. replaced that but still was same. i dont know how that came up. but hey i solved the problem. thanks everyone 😀That’s awesome. I had a feeling it was a coil but couldn’t get on the same page about picking it out. Their is actually several ways to test COP but they require some advanced tools. To explain why you had spark when you took it out is that it takes very little effort to fire outside the cylinder but lots of effort to fire inside the cylinder with compression. So like you said weak coil. COP’s go bad all the time. I’m glad you got it.
- You must be logged in to reply to this topic.