CammedS197
forum member
Hey guys,
Been searching for about a day or so and I cannot find something similar.
So to start off, About a month ago after stopping to get food and starting my car up after about a minute it all of a sudden started to idle at about 10:1 AFR and if I gave it some throttle it would stutter as in way too much fuel and not a spark issue. After about a minute back to normal and that little rich time was gone. Now it has done it a few more times lately and now will sometimes surge when I clutch in. Drops to 500 up to 1000rpm and settles at 750.
The AFR will follow the idle and go up and down with it. I have also noticed that if I rev the car AFR will drop to 10 or 11 and then spike up to 17ish and back to normal.
The only times I have ever noticed it do that pig rich idle where it wants to almost stall out is only shortly after a start up but the car is already hot. If car is cold it will not do it. But you know it just wont do it if I'm logging though.
WOT is still strong no issues there and regular accel and driving is fine. I don't feel this in my driving but if I do a rev and rpm comes back down AFR will be around 12-13 and if I hit it again it will have that slight hesitation due to too much fuel. Last night it did it again after starting up from being driven shortly before and it only happens about a minute or two after starting and lasts for maybe just a minute.
AFR was normal and then bam all of a sudden it went from Stoich and dropped into the 12-13 range and slowly climbed down all the way to 9.xx AFR then went right back to normal. I was only moving slow in 2nd gear due to bumpy road and kids. I wasn't able to see if being that rich affected it.
The car is a 2006 Mustang GT. Tuned by Lito (trying to get him a log with it) and has Longtubes, detroit rocker cams, off road H, MBRP mufflers, Airaid CAI, and GT500 throttle body. All of these have been on the car for over a year. No new mods.
This happened on 2 different tunes and I know it is not the tune. Been using Lito for 3 -4 years now. Tried on my 87 octane tune for when we get hurricanes (seems more dramatic or pronounced on 87) and then my 93 octane tune as well. Same thing for both.
Now my plan so far: Going to clean the MAF and throttle body and swap out the fuel filter within the next few days.
Plugs are at 40k miles, COPs are at 125k miles (I have a whole new set in my garage) Front o2 sensors are at 125k miles as well. I plan on swapping the o2 sensors at some time as well with the NTK's.
Was also thinking the Fuel pressure sensor or TPS could possibly be a culprit.
Going to start out with the cleaning of the simple crap and see what happens. Can a fuel pressure sensor be cleaned? The TPS on the GT500 throttle body is about 1.5 years old and about 20k miles on it.
I'm assuming all of these possibilities are able to be seen in a log except for the COPs and plugs?
Thanks guys,
James
Been searching for about a day or so and I cannot find something similar.
So to start off, About a month ago after stopping to get food and starting my car up after about a minute it all of a sudden started to idle at about 10:1 AFR and if I gave it some throttle it would stutter as in way too much fuel and not a spark issue. After about a minute back to normal and that little rich time was gone. Now it has done it a few more times lately and now will sometimes surge when I clutch in. Drops to 500 up to 1000rpm and settles at 750.
The AFR will follow the idle and go up and down with it. I have also noticed that if I rev the car AFR will drop to 10 or 11 and then spike up to 17ish and back to normal.
The only times I have ever noticed it do that pig rich idle where it wants to almost stall out is only shortly after a start up but the car is already hot. If car is cold it will not do it. But you know it just wont do it if I'm logging though.
WOT is still strong no issues there and regular accel and driving is fine. I don't feel this in my driving but if I do a rev and rpm comes back down AFR will be around 12-13 and if I hit it again it will have that slight hesitation due to too much fuel. Last night it did it again after starting up from being driven shortly before and it only happens about a minute or two after starting and lasts for maybe just a minute.
AFR was normal and then bam all of a sudden it went from Stoich and dropped into the 12-13 range and slowly climbed down all the way to 9.xx AFR then went right back to normal. I was only moving slow in 2nd gear due to bumpy road and kids. I wasn't able to see if being that rich affected it.
The car is a 2006 Mustang GT. Tuned by Lito (trying to get him a log with it) and has Longtubes, detroit rocker cams, off road H, MBRP mufflers, Airaid CAI, and GT500 throttle body. All of these have been on the car for over a year. No new mods.
This happened on 2 different tunes and I know it is not the tune. Been using Lito for 3 -4 years now. Tried on my 87 octane tune for when we get hurricanes (seems more dramatic or pronounced on 87) and then my 93 octane tune as well. Same thing for both.
Now my plan so far: Going to clean the MAF and throttle body and swap out the fuel filter within the next few days.
Plugs are at 40k miles, COPs are at 125k miles (I have a whole new set in my garage) Front o2 sensors are at 125k miles as well. I plan on swapping the o2 sensors at some time as well with the NTK's.
Was also thinking the Fuel pressure sensor or TPS could possibly be a culprit.
Going to start out with the cleaning of the simple crap and see what happens. Can a fuel pressure sensor be cleaned? The TPS on the GT500 throttle body is about 1.5 years old and about 20k miles on it.
I'm assuming all of these possibilities are able to be seen in a log except for the COPs and plugs?
Thanks guys,
James