Engine "miss", hesitation, vibration
06-20-2012, 12:28 AM
#1
Thread Starter
Join Date: Jun 2012
Location: Illinois
Posts: 2
Engine "miss", hesitation, vibration
Hello to everyone here, this is my first post to mustangforums.com!
I have read many posts from the site, and have decided to register now, in hopes that I may join this wonderful community and fix my current (and future) problems with my Mustang.
I drive a 1996 Mustang GT Convertible 5-speed manual that I bought 8 months ago (stored for winter) with 113,000 miles (now has 118,000). When I bought it, there was a hesitation when accelerating, in any gear, but if I was hot rodding it, the hesitation went away. To try to explain this, at a stoplight on flat ground, I start out in first gear, the RPMs consistently go up, but every second of acceleration feels like the engine peaks out and drops a few hundred RPMs then keeps going up. It's like I give it gas then take my foot away a quarter of a second then press down again. But if I take off at the stoplight and almost redline it through the gears, there is no issue whatsoever.
This same issue is also noticed on an incline such as a small slope or hill, also in any gear. Most noteably in 5th gear, while crusing on the highway and accelerating as little as 1mph. I am wondering if it is a fuel injection issue, an engine issue, or possibly a transmission issue (such as a throw out bearing, with noticeable problems while at low torque such as 1st gear at a stoplight, or cruising in 5th gear on the highway)
So I have replaced the spark plugs with Bosch (iridium) I believe it was from O'Reillys, the Motorcraft Spark Plug Wires that I believe are the same model # as the OEM, not sure if they are exactly the same or not but they matched from Amazon for the 1996 Mustang GT. And lastly I have replaced the coil packs with MSD ones from American Muscle. Even after replacing all of these, I still have the same exact problems. I have cleaned the IAC Valve also, as well as my air filter and connecting tube to the throttle body, and have cleaned that as well. Have run Seafoam through the gas tank twice now, and I rotate running 89 and 93 octane gas in the tank. Havent changed the fuel filter yet, nor the fuel pump or oil pump or fuel injectors.
The only aftermarket modifications to the car engine/exhaust wise are:
K&N air filter (non-disposable, reusable air filter)
BBK Underdrive pulleys
Magnaflow x-pipes
(^^all were installed before I owned the car)
I am not sure if the MAF is aftermarket or not.
I bought the car used as the 4th owner, no accidents, clean Carfax. Like I said, the problem was there when I bought the car, and was hoping it was a simple fix, but so far has not been =/ I have read several of the posts on here and other sites about somewhat similar problems, but havent been able to fix this.
Please help me! Anything is appreciated!!! Thank you all so much
I have read many posts from the site, and have decided to register now, in hopes that I may join this wonderful community and fix my current (and future) problems with my Mustang.
I drive a 1996 Mustang GT Convertible 5-speed manual that I bought 8 months ago (stored for winter) with 113,000 miles (now has 118,000). When I bought it, there was a hesitation when accelerating, in any gear, but if I was hot rodding it, the hesitation went away. To try to explain this, at a stoplight on flat ground, I start out in first gear, the RPMs consistently go up, but every second of acceleration feels like the engine peaks out and drops a few hundred RPMs then keeps going up. It's like I give it gas then take my foot away a quarter of a second then press down again. But if I take off at the stoplight and almost redline it through the gears, there is no issue whatsoever.
This same issue is also noticed on an incline such as a small slope or hill, also in any gear. Most noteably in 5th gear, while crusing on the highway and accelerating as little as 1mph. I am wondering if it is a fuel injection issue, an engine issue, or possibly a transmission issue (such as a throw out bearing, with noticeable problems while at low torque such as 1st gear at a stoplight, or cruising in 5th gear on the highway)
So I have replaced the spark plugs with Bosch (iridium) I believe it was from O'Reillys, the Motorcraft Spark Plug Wires that I believe are the same model # as the OEM, not sure if they are exactly the same or not but they matched from Amazon for the 1996 Mustang GT. And lastly I have replaced the coil packs with MSD ones from American Muscle. Even after replacing all of these, I still have the same exact problems. I have cleaned the IAC Valve also, as well as my air filter and connecting tube to the throttle body, and have cleaned that as well. Have run Seafoam through the gas tank twice now, and I rotate running 89 and 93 octane gas in the tank. Havent changed the fuel filter yet, nor the fuel pump or oil pump or fuel injectors.
The only aftermarket modifications to the car engine/exhaust wise are:
K&N air filter (non-disposable, reusable air filter)
BBK Underdrive pulleys
Magnaflow x-pipes
(^^all were installed before I owned the car)
I am not sure if the MAF is aftermarket or not.
I bought the car used as the 4th owner, no accidents, clean Carfax. Like I said, the problem was there when I bought the car, and was hoping it was a simple fix, but so far has not been =/ I have read several of the posts on here and other sites about somewhat similar problems, but havent been able to fix this.
Please help me! Anything is appreciated!!! Thank you all so much
06-20-2012, 10:27 AM
#3
Hello to everyone here, this is my first post to mustangforums.com!
I have read many posts from the site, and have decided to register now, in hopes that I may join this wonderful community and fix my current (and future) problems with my Mustang.
I drive a 1996 Mustang GT Convertible 5-speed manual that I bought 8 months ago (stored for winter) with 113,000 miles (now has 118,000). When I bought it, there was a hesitation when accelerating, in any gear, but if I was hot rodding it, the hesitation went away. To try to explain this, at a stoplight on flat ground, I start out in first gear, the RPMs consistently go up, but every second of acceleration feels like the engine peaks out and drops a few hundred RPMs then keeps going up. It's like I give it gas then take my foot away a quarter of a second then press down again. But if I take off at the stoplight and almost redline it through the gears, there is no issue whatsoever.
This same issue is also noticed on an incline such as a small slope or hill, also in any gear. Most noteably in 5th gear, while crusing on the highway and accelerating as little as 1mph. I am wondering if it is a fuel injection issue, an engine issue, or possibly a transmission issue (such as a throw out bearing, with noticeable problems while at low torque such as 1st gear at a stoplight, or cruising in 5th gear on the highway)
So I have replaced the spark plugs with Bosch (iridium) I believe it was from O'Reillys, the Motorcraft Spark Plug Wires that I believe are the same model # as the OEM, not sure if they are exactly the same or not but they matched from Amazon for the 1996 Mustang GT. And lastly I have replaced the coil packs with MSD ones from American Muscle. Even after replacing all of these, I still have the same exact problems. I have cleaned the IAC Valve also, as well as my air filter and connecting tube to the throttle body, and have cleaned that as well. Have run Seafoam through the gas tank twice now, and I rotate running 89 and 93 octane gas in the tank. Havent changed the fuel filter yet, nor the fuel pump or oil pump or fuel injectors.
The only aftermarket modifications to the car engine/exhaust wise are:
K&N air filter (non-disposable, reusable air filter)
BBK Underdrive pulleys
Magnaflow x-pipes
(^^all were installed before I owned the car)
I am not sure if the MAF is aftermarket or not.
I bought the car used as the 4th owner, no accidents, clean Carfax. Like I said, the problem was there when I bought the car, and was hoping it was a simple fix, but so far has not been =/ I have read several of the posts on here and other sites about somewhat similar problems, but havent been able to fix this.
Please help me! Anything is appreciated!!! Thank you all so much
I have read many posts from the site, and have decided to register now, in hopes that I may join this wonderful community and fix my current (and future) problems with my Mustang.
I drive a 1996 Mustang GT Convertible 5-speed manual that I bought 8 months ago (stored for winter) with 113,000 miles (now has 118,000). When I bought it, there was a hesitation when accelerating, in any gear, but if I was hot rodding it, the hesitation went away. To try to explain this, at a stoplight on flat ground, I start out in first gear, the RPMs consistently go up, but every second of acceleration feels like the engine peaks out and drops a few hundred RPMs then keeps going up. It's like I give it gas then take my foot away a quarter of a second then press down again. But if I take off at the stoplight and almost redline it through the gears, there is no issue whatsoever.
This same issue is also noticed on an incline such as a small slope or hill, also in any gear. Most noteably in 5th gear, while crusing on the highway and accelerating as little as 1mph. I am wondering if it is a fuel injection issue, an engine issue, or possibly a transmission issue (such as a throw out bearing, with noticeable problems while at low torque such as 1st gear at a stoplight, or cruising in 5th gear on the highway)
So I have replaced the spark plugs with Bosch (iridium) I believe it was from O'Reillys, the Motorcraft Spark Plug Wires that I believe are the same model # as the OEM, not sure if they are exactly the same or not but they matched from Amazon for the 1996 Mustang GT. And lastly I have replaced the coil packs with MSD ones from American Muscle. Even after replacing all of these, I still have the same exact problems. I have cleaned the IAC Valve also, as well as my air filter and connecting tube to the throttle body, and have cleaned that as well. Have run Seafoam through the gas tank twice now, and I rotate running 89 and 93 octane gas in the tank. Havent changed the fuel filter yet, nor the fuel pump or oil pump or fuel injectors.
The only aftermarket modifications to the car engine/exhaust wise are:
K&N air filter (non-disposable, reusable air filter)
BBK Underdrive pulleys
Magnaflow x-pipes
(^^all were installed before I owned the car)
I am not sure if the MAF is aftermarket or not.
I bought the car used as the 4th owner, no accidents, clean Carfax. Like I said, the problem was there when I bought the car, and was hoping it was a simple fix, but so far has not been =/ I have read several of the posts on here and other sites about somewhat similar problems, but havent been able to fix this.
Please help me! Anything is appreciated!!! Thank you all so much
blacksunshine_96GT,
Welcome to MustangForums! I assure you, you'll really enjoy being apart of this forum and communicating back and forth with other Mustang Enthusiasts to fix issues or just talk about your favorite products!
I know it's really frustrating when the simple fixes don't seem to work. With what you described, I would look for a few different things. First- you should definitely change the fuel filter regardless. Who knows when the last time it was changed. Next- take a look at your fuel injectors in case of a semi clogged injector. Last- is search everywhere you can think of for vacuum leaks, this is an easy one to miss, but can have a huge effect on your Stangs driveability.
Post back and let me know how you make out or if you have any other questions!
Shane
06-21-2012, 11:24 AM
#4
Thread Starter
Join Date: Jun 2012
Location: Illinois
Posts: 2
The previoius owner did not re-install the catalytic converters after having the aftermarket exhaust installed.
Thanks! I am sure I will make good use of and learn a lot from these forums!
I will be replacing the fuel filter here soon within the next few days when I have the time. So far, all of the hoses seem to be fine without any cracks/tears. As for the injectors, I have ran Seafoam through my gas tank several times, but other than that, haven't cleaned the injectors out a different way. Do you have any good suggestions on the best/proper way to do this?
Thanks everyone!
blacksunshine_96GT,
Welcome to MustangForums! I assure you, you'll really enjoy being apart of this forum and communicating back and forth with other Mustang Enthusiasts to fix issues or just talk about your favorite products!
I know it's really frustrating when the simple fixes don't seem to work. With what you described, I would look for a few different things. First- you should definitely change the fuel filter regardless. Who knows when the last time it was changed. Next- take a look at your fuel injectors in case of a semi clogged injector. Last- is search everywhere you can think of for vacuum leaks, this is an easy one to miss, but can have a huge effect on your Stangs driveability.
Post back and let me know how you make out or if you have any other questions!
Shane
Welcome to MustangForums! I assure you, you'll really enjoy being apart of this forum and communicating back and forth with other Mustang Enthusiasts to fix issues or just talk about your favorite products!
I know it's really frustrating when the simple fixes don't seem to work. With what you described, I would look for a few different things. First- you should definitely change the fuel filter regardless. Who knows when the last time it was changed. Next- take a look at your fuel injectors in case of a semi clogged injector. Last- is search everywhere you can think of for vacuum leaks, this is an easy one to miss, but can have a huge effect on your Stangs driveability.
Post back and let me know how you make out or if you have any other questions!
Shane
I will be replacing the fuel filter here soon within the next few days when I have the time. So far, all of the hoses seem to be fine without any cracks/tears. As for the injectors, I have ran Seafoam through my gas tank several times, but other than that, haven't cleaned the injectors out a different way. Do you have any good suggestions on the best/proper way to do this?
Thanks everyone!
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