1987 Mustang Idle & Low RPM Trouble
#1
1987 Mustang Idle & Low RPM Trouble
Okay....me and dad are exhausted.....so I'm going to the pros.
The car is a 1987 Ford Mustang. Bone Stock, like it came from the factory. At idle it surges from about 800 rpm (almost dies out, but not quite) to 1500. While riding at low RPMs, it chuggs, after you get up to speed, it runs fine. It is using WAAAAAAY too much fuel. We put it on a diagnostic check from a friend, and it says that the EGR valve and the o2 sensor number 2 is the problem. It says the car is putting out DOUBLE as much gas as it is supposed to. So dad and I have replaced the following.
Both o2 sensors. Did nothing to help the problem.
Both the EGR valve and sensor. Did nothing to help the problem.
Have also replaced the Throttle positioning sensor. Did nothing to help the problem.
Anyone have ANY ideas? Our newest thought was that it may be the Fuel Pressure Regulator, but we aren't 100%. Any input would and will be appreciated.
The car is a 1987 Ford Mustang. Bone Stock, like it came from the factory. At idle it surges from about 800 rpm (almost dies out, but not quite) to 1500. While riding at low RPMs, it chuggs, after you get up to speed, it runs fine. It is using WAAAAAAY too much fuel. We put it on a diagnostic check from a friend, and it says that the EGR valve and the o2 sensor number 2 is the problem. It says the car is putting out DOUBLE as much gas as it is supposed to. So dad and I have replaced the following.
Both o2 sensors. Did nothing to help the problem.
Both the EGR valve and sensor. Did nothing to help the problem.
Have also replaced the Throttle positioning sensor. Did nothing to help the problem.
Anyone have ANY ideas? Our newest thought was that it may be the Fuel Pressure Regulator, but we aren't 100%. Any input would and will be appreciated.
#2
RE: 1987 Mustang Idle & Low RPM Trouble
that should of fixed it..maybe?....did you by chance recheck for codes??....did you clear the computer???just unhook the cables and let sit for 30 min....
#4
RE: 1987 Mustang Idle & Low RPM Trouble
could have a plugged or bad vac. line/tree by the egr valve???
ORIGINAL: 88BlueGT
I have the same problem but Im almost positive that mine are due to vaccume lines. Are all of your vac lines hooked up correctly?
I have the same problem but Im almost positive that mine are due to vaccume lines. Are all of your vac lines hooked up correctly?
#5
RE: 1987 Mustang Idle & Low RPM Trouble
Well I do know of 1 vaccum line that is disconnected, but it has been disconnected for a looooong time, possibly 3 to 4 years, so I son't think that that is the problem.
And as for the diagnostic check, we ran it twice. once with car turned off, and once while the car was on. Will disconnecting for 30 minutes change anything?
And does anyone here even think it is the Fuel pressure regulator, or if it is worth it for us to try and replace?
And as for the diagnostic check, we ran it twice. once with car turned off, and once while the car was on. Will disconnecting for 30 minutes change anything?
And does anyone here even think it is the Fuel pressure regulator, or if it is worth it for us to try and replace?
#7
RE: 1987 Mustang Idle & Low RPM Trouble
have same model car and everything, had same problem, turned out mine was the vacuum lines, and a bad Idle control valve gasket, so i ended up replaceing the whole valve, now it idles perfect, look into that stuff, b/c i spent weeks with this problem, and so many solutions, turned out to be those 2 things.. i no whats its like to have idle problems
#8
RE: 1987 Mustang Idle & Low RPM Trouble
ORIGINAL: Scooterman
have same model car and everything, had same problem, turned out mine was the vacuum lines, and a bad Idle control valve gasket, so i ended up replaceing the whole valve, now it idles perfect, look into that stuff, b/c i spent weeks with this problem, and so many solutions, turned out to be those 2 things.. i no whats its like to have idle problems
have same model car and everything, had same problem, turned out mine was the vacuum lines, and a bad Idle control valve gasket, so i ended up replaceing the whole valve, now it idles perfect, look into that stuff, b/c i spent weeks with this problem, and so many solutions, turned out to be those 2 things.. i no whats its like to have idle problems
And also, why would the computer tell us it was using twice the amount of gas it was supposed to use, if the problem was the vaccum lines? Would the vaccum lines make it run like that? The twice as much gas thing is what led us to believe it was a fuel/exhaust problem....
#9
RE: 1987 Mustang Idle & Low RPM Trouble
Update: Did the engine coil. Nothing changed. However, when we replaced the EGR valve, sensor, and H2o sensor, we were not aware you had to reset the computer to get them to take effect, so, looks like we'll have to reset the computer soon, and see what we get. If it doesn't work, then all I can say is, vaccum lines here we come.
#10
RE: 1987 Mustang Idle & Low RPM Trouble
The best way to reset the computer is unhook the bat leave unhooked for 5 min, hook it back up let the car idle for 2 min with no acc on then turn on ac let idle for 2 more min then your ready to go. That process is what ford recemends.