misfire issue! everyone stumped please help
08-29-2007, 08:18 PM
#11
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Join Date: Jan 2007
Location: Eureka, Ca.
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RE: misfire issue! everyone stumped please help
ORIGINAL: cobra232
everything else should store a code if it's a bad plug or IAC or Cam Position sensor. sometimes the cranksensors when they are old don't work as good as they should on alot of cars but that usually causes then not to restart till they cool
everything else should store a code if it's a bad plug or IAC or Cam Position sensor. sometimes the cranksensors when they are old don't work as good as they should on alot of cars but that usually causes then not to restart till they cool
That's not correct. If the IAC's motor is still working and the plunger can still be stuck and it will NOT throw a code. I've seen it happen several times.
If the plunger was moving then that's not the problem.
08-29-2007, 09:52 PM
#12
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Join Date: Mar 2004
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RE: misfire issue! everyone stumped please help
ORIGINAL: raz54
That's not correct. If the IAC's motor is still working and the plunger can still be stuck and it will NOT throw a code. I've seen it happen several times.
If the plunger was moving then that's not the problem.
ORIGINAL: cobra232
everything else should store a code if it's a bad plug or IAC or Cam Position sensor. sometimes the cranksensors when they are old don't work as good as they should on alot of cars but that usually causes then not to restart till they cool.
everything else should store a code if it's a bad plug or IAC or Cam Position sensor. sometimes the cranksensors when they are old don't work as good as they should on alot of cars but that usually causes then not to restart till they cool.
That's not correct. If the IAC's motor is still working and the plunger can still be stuck and it will NOT throw a code. I've seen it happen several times.
If the plunger was moving then that's not the problem.
08-29-2007, 10:14 PM
#13
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Join Date: Jan 2007
Location: Eureka, Ca.
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RE: misfire issue! everyone stumped please help
I'm not going to argue about it but I've seen it happen with NO codes but anyway I don't think his problem oil related. If it was it should run crappy all the time, not just when it warms up. I had a car with broken rings, burning oil and fouling plugs and if anything it was worse when cold.
BTW. I had to run 'hotter' plugs to keep them from fouling so quick, not colder.
BTW. I had to run 'hotter' plugs to keep them from fouling so quick, not colder.
08-29-2007, 10:40 PM
#14
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Join Date: Mar 2004
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RE: misfire issue! everyone stumped please help
ORIGINAL: raz54
I'm not going to argue about it but I've seen it happen with NO codes but anyway I don't think his problem oil related. If it was it should run crappy all the time, not just when it warms up. I had a car with broken rings, burning oil and fouling plugs and if anything it was worse when cold.
BTW. I had to run 'hotter' plugs to keep them from fouling so quick, not colder.
I'm not going to argue about it but I've seen it happen with NO codes but anyway I don't think his problem oil related. If it was it should run crappy all the time, not just when it warms up. I had a car with broken rings, burning oil and fouling plugs and if anything it was worse when cold.
BTW. I had to run 'hotter' plugs to keep them from fouling so quick, not colder.
BTW define hot vs cold plug if you will
08-30-2007, 12:06 AM
#15
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Join Date: Jan 2007
Location: Eureka, Ca.
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RE: misfire issue! everyone stumped please help
Read this. It's right from NGK's site. Funny, it doesn't say to go colder with oil burning but rather hotter. The link I got it from is below at the bottom of the page.
" A hotter heat range is not usually recommended except when severe oil or fuel fouling is occurring."
http://www.ngksparkplugs.com/techinf...200&country=US
You're confusing oil burning with carbon deposits. When you are burning oil you need a hotter plug to keep it from fouling. When you have carbon deposits you need a colder plug to prevent detonation. Get your facts right and stop confusing people with your lack of knowledge.
I re-read the original post and I'm thinking the temp sensor. Not the one for the gauge, the one for the computer so it knows the temp of the motor to either richen or lean it out.
" A hotter heat range is not usually recommended except when severe oil or fuel fouling is occurring."
http://www.ngksparkplugs.com/techinf...200&country=US
You're confusing oil burning with carbon deposits. When you are burning oil you need a hotter plug to keep it from fouling. When you have carbon deposits you need a colder plug to prevent detonation. Get your facts right and stop confusing people with your lack of knowledge.
I re-read the original post and I'm thinking the temp sensor. Not the one for the gauge, the one for the computer so it knows the temp of the motor to either richen or lean it out.
08-30-2007, 02:00 PM
#16
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
RE: misfire issue! everyone stumped please help
ORIGINAL: xflashjr
Hey Everyone,
First off wanted to introduce myself and the car. I have always owned imports of some type and I am not too familiar with American cars but lately it seems I am learning pretty quickly with the latest problem I have.
The car is a 2000 v6 auto vert. Car has high miles (170 k) but has run great up until a 2 weeks ago. I purchased the car for my girlfriend a month ago and while my car is in the shop I have been driving it around. I was greatly impressed how great the car drove and ran for the high miles (all highway miles) but attributed it to all highway miles that kept the car feeling new.
This past weekend I noticed a misfire under 2500 rpms. It was slightly noticeable on idle with a minor vibration but under load it felt like I was driving down a slightly bumpy road at 1500 rpms. The car would smooth out just fine on interstate speeds. I decided to do the regular items and replaced the plugs. Soon after I replaced he plugs I had a check engine light on which ultimately read misfire in cylinder number one. I went ahead and bought new wires, coil, and another plug for that cylinder. I reset the code myself and it has notcome back on since.
This miss was just as bad if not worse and brought it to a mechanic friend of mine. He is ASE certified and is one of the most competent mechanic I know. He ended up putting it on a diagnostic machine. There were no stored codes, showed all injectors were working as well as all sensors. If we powered breaked the car to 1500 rpm's you could feel the car and engine shake right before the tires would brake loose. He said the issue only really happened under load. He checked the O2 sensors under load and he said that BANK one sensor two was running very rich during the miss.
Now if we let the car cool down it would not do it for the first minute or two but would combine shortly after. He decided he felt it could be three other things. Bad driver in the PCM, Low compression in that cylinder or a leaky injector for that cylinder. He used a testlight on the new coil while the car was running to determine that it was in fact cylinder number one causing the issue.
I did a quick compression test on that cylinder earlier today. I did it with the rest of the plugs in using a plunger style adapter (my two screw on adapters did not fit) Knowing that the plunger types read low I was still happy with the 120 psi reading I got. I still need to do another cylinder to compare but that number does not seem to be low enough to be the cause of the misfire.
Also the car does not put out any white smoke and even though their is black soot on the tailpipe you can only get a very small amount of black smoke to come out when the car is repeatedly floored. When I pulled the plug out to do the test I examined the plug and it had some wet substance on it but very heavily smelled of gasoline.
I am hoping it is a leaky injector that is stuck open but in order to swap it I would need to pull off the intake manifold which does not seem like alot of fun. Any ideas or thoughts would be greatly appreciated!
Thanks
Steve
Hey Everyone,
First off wanted to introduce myself and the car. I have always owned imports of some type and I am not too familiar with American cars but lately it seems I am learning pretty quickly with the latest problem I have.
The car is a 2000 v6 auto vert. Car has high miles (170 k) but has run great up until a 2 weeks ago. I purchased the car for my girlfriend a month ago and while my car is in the shop I have been driving it around. I was greatly impressed how great the car drove and ran for the high miles (all highway miles) but attributed it to all highway miles that kept the car feeling new.
This past weekend I noticed a misfire under 2500 rpms. It was slightly noticeable on idle with a minor vibration but under load it felt like I was driving down a slightly bumpy road at 1500 rpms. The car would smooth out just fine on interstate speeds. I decided to do the regular items and replaced the plugs. Soon after I replaced he plugs I had a check engine light on which ultimately read misfire in cylinder number one. I went ahead and bought new wires, coil, and another plug for that cylinder. I reset the code myself and it has notcome back on since.
This miss was just as bad if not worse and brought it to a mechanic friend of mine. He is ASE certified and is one of the most competent mechanic I know. He ended up putting it on a diagnostic machine. There were no stored codes, showed all injectors were working as well as all sensors. If we powered breaked the car to 1500 rpm's you could feel the car and engine shake right before the tires would brake loose. He said the issue only really happened under load. He checked the O2 sensors under load and he said that BANK one sensor two was running very rich during the miss.
Now if we let the car cool down it would not do it for the first minute or two but would combine shortly after. He decided he felt it could be three other things. Bad driver in the PCM, Low compression in that cylinder or a leaky injector for that cylinder. He used a testlight on the new coil while the car was running to determine that it was in fact cylinder number one causing the issue.
I did a quick compression test on that cylinder earlier today. I did it with the rest of the plugs in using a plunger style adapter (my two screw on adapters did not fit) Knowing that the plunger types read low I was still happy with the 120 psi reading I got. I still need to do another cylinder to compare but that number does not seem to be low enough to be the cause of the misfire.
Also the car does not put out any white smoke and even though their is black soot on the tailpipe you can only get a very small amount of black smoke to come out when the car is repeatedly floored. When I pulled the plug out to do the test I examined the plug and it had some wet substance on it but very heavily smelled of gasoline.
I am hoping it is a leaky injector that is stuck open but in order to swap it I would need to pull off the intake manifold which does not seem like alot of fun. Any ideas or thoughts would be greatly appreciated!
Thanks
Steve
How old are the wires? How old are the plugs? Are any of your wires making contact with metal or are they just old? The running rich is probably a byproduct of the misfire since you're basically throwing unburnt fuel into the exhaust past the O2 sensors.
Start simple first.
08-30-2007, 02:50 PM
#17
Thread Starter
Join Date: Aug 2007
Posts: 8
RE: misfire issue! everyone stumped please help
Hey all,
I tried the seafoam thing last night, it did nto seem to make a diffrence that day but this morning the car seemed to run better. Unfortuatly after 15 mins or so the problems came back. When I changed the plugs the first time cylinder number 6 was completly covered in soot. Cylinder number looked fairly clean. If the pcv system really does that much damage to those cylinders then I need to focus on that I suppose. I think a full compression test is in order.
The plugs, wires ,ad coil are not even a week old yet so I doubt it is that especilyl since I have used mutliple diffrent wires on cylinder one.
Raz how should I test the temp sensor? Should I pull it off and start the car to see if their is a diffrence. When I put it on the diagnostic tool I did not see any bad sensors.
A part of me is thinking is is a problem with the valves in cylinder one possibly. I might pull the valve cover this weekend and see what I find it anything.
Thanks for all the replies they are great!
I tried the seafoam thing last night, it did nto seem to make a diffrence that day but this morning the car seemed to run better. Unfortuatly after 15 mins or so the problems came back. When I changed the plugs the first time cylinder number 6 was completly covered in soot. Cylinder number looked fairly clean. If the pcv system really does that much damage to those cylinders then I need to focus on that I suppose. I think a full compression test is in order.
The plugs, wires ,ad coil are not even a week old yet so I doubt it is that especilyl since I have used mutliple diffrent wires on cylinder one.
Raz how should I test the temp sensor? Should I pull it off and start the car to see if their is a diffrence. When I put it on the diagnostic tool I did not see any bad sensors.
A part of me is thinking is is a problem with the valves in cylinder one possibly. I might pull the valve cover this weekend and see what I find it anything.
Thanks for all the replies they are great!
08-30-2007, 02:55 PM
#18
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
RE: misfire issue! everyone stumped please help
ORIGINAL: xflashjr
Hey all,
I tried the seafoam thing last night, it did nto seem to make a diffrence that day but this morning the car seemed to run better. Unfortuatly after 15 mins or so the problems came back. When I changed the plugs the first time cylinder number 6 was completly covered in soot. Cylinder number looked fairly clean. If the pcv system really does that much damage to those cylinders then I need to focus on that I suppose. I think a full compression test is in order.
The plugs, wires ,ad coil are not even a week old yet so I doubt it is that especilyl since I have used mutliple diffrent wires on cylinder one.
Raz how should I test the temp sensor? Should I pull it off and start the car to see if their is a diffrence. When I put it on the diagnostic tool I did not see any bad sensors.
A part of me is thinking is is a problem with the valves in cylinder one possibly. I might pull the valve cover this weekend and see what I find it anything.
Thanks for all the replies they are great!
Hey all,
I tried the seafoam thing last night, it did nto seem to make a diffrence that day but this morning the car seemed to run better. Unfortuatly after 15 mins or so the problems came back. When I changed the plugs the first time cylinder number 6 was completly covered in soot. Cylinder number looked fairly clean. If the pcv system really does that much damage to those cylinders then I need to focus on that I suppose. I think a full compression test is in order.
The plugs, wires ,ad coil are not even a week old yet so I doubt it is that especilyl since I have used mutliple diffrent wires on cylinder one.
Raz how should I test the temp sensor? Should I pull it off and start the car to see if their is a diffrence. When I put it on the diagnostic tool I did not see any bad sensors.
A part of me is thinking is is a problem with the valves in cylinder one possibly. I might pull the valve cover this weekend and see what I find it anything.
Thanks for all the replies they are great!
Do a compression check first, that will help weed out cylinder problems.
And it's not the PCV system itself that is faulty, it's the baffle design in the 99-00 valve covers that causes the carbon build-up. Here's an article on it.
http://www.miracerros.com/mustang/pcv_filter.htm
08-30-2007, 03:52 PM
#19
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Join Date: Jan 2007
Location: Eureka, Ca.
Posts: 1,758
RE: misfire issue! everyone stumped please help
I would forget the baffle for now, that's not what's causing your problem Over time though the valves and pistons will carbon up but that will cause detonation (pinging). When you do the compression test all the plugs need to be all out and the difference between the lowest and highest should be within 10% of each other. Make sure you check all the plugs to see if any are wet or dark in color. You said he used a test light to determine it was cly number 1. Is it in fact #1 missing? If it is forget the temp sensor.
08-30-2007, 08:18 PM
#20
2nd Gear Member
Join Date: Mar 2007
Location:
Posts: 201
RE: misfire issue! everyone stumped please help
I just got my 97 fixed. I had to take it to the dealer because no one knew what was wrong.
My car missed badly and no power.
The bolt on theharmonic balancer was loose and caused the timing to be off. It needed a new balancer and timing gear. Just strange to me that the bolt came loose on this 97 with 86,000 miles on it. Weird weird weird. But I got it back today and it runs like new again. I put left foot on brake and right foot on gas and did a burn out like the old car would do. This is something easy to look at just grab the bottom pulley and see if it is loose or get down there and put the socket on the bolt that holds it in and see if it is loose.
My car missed badly and no power.
The bolt on theharmonic balancer was loose and caused the timing to be off. It needed a new balancer and timing gear. Just strange to me that the bolt came loose on this 97 with 86,000 miles on it. Weird weird weird. But I got it back today and it runs like new again. I put left foot on brake and right foot on gas and did a burn out like the old car would do. This is something easy to look at just grab the bottom pulley and see if it is loose or get down there and put the socket on the bolt that holds it in and see if it is loose.