I have a '95 MTX that is giving me grief. I took apart the intake manifold and cleaned it yesterday with carb cleaner then put it back together today. When I turned on the ingnition, the idle was higher than normal (approx. 1500 RPM) and so I opened the hood to adjust. When I opened the hood, I heard a somewhat loud knock in the engine. I immediately turned it off and began smelling an oil-like burn. Someone please help me figure out what I did wrong and how I can fix it.
Help!!!!!!!!!!
- Thread starter 2Fast4U
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
projectSHO89
SHOless In St L
My guess is that some of the carb cleaner backfired in the intake manifold.
Unfortunately, it is impossible to further diagnose what may be wrong if there are additional concerns. It is possible that the engine is fine and that the "knock" was a one time occurrance. It is also possible that the engine was damaged, however, only an inspection could determine that.
The high idle most likely is being caused by a vacuum leak somewhere on or near the intake.
Good luck and let us know what you find.
Steve
Unfortunately, it is impossible to further diagnose what may be wrong if there are additional concerns. It is possible that the engine is fine and that the "knock" was a one time occurrance. It is also possible that the engine was damaged, however, only an inspection could determine that.
The high idle most likely is being caused by a vacuum leak somewhere on or near the intake.
Good luck and let us know what you find.
Steve
Mr Anonymous
Tire Wall
Did you drop something into the the heads/valves when you had the intake off? It's usually a good idea to inspect before reinstalling the intake. Oh, and you do know that the idle on a SHO is controlled by the PCM via the IAC, and cannot be manually adjusted, right? The stop screw on the throttle body is not for idle adjustment. I recommend removing the intake again and checking each head port for foreign objects.
I restarted the engine and let it run for several minutes. The kocking occured only once more, but it was much, much less alarming than before. Because the knock happened after the engine was warm, I suspect that you are right about the carb cleaner being the cause.
The idle, however, is still extremely high. It is idling at nearly *2500* RPM!! I adjusted the air filter to make sure it was on tight. (A lesson I learned a couple years ago on another SHO) After I adjusted it, the RPM came down to normal for a few seconds and then went back up after I revved the engine a little. The weird thing is that the idle is NOT fluctuating at all. Isn't fluctuating normally the sign of a vacuum leak?
I drove around the block and experienced the same high idle. I was very careful when reinstalling the manifold not to drop anything! I had a friend with me to make sure that didn't happen, so I am fairly certain that nothing fell in. I know that the idle cannot be manually adjusted, but is there ANYTHING I can do to bring it down without having to take it in and hooked up to a computer???
Deven
The idle, however, is still extremely high. It is idling at nearly *2500* RPM!! I adjusted the air filter to make sure it was on tight. (A lesson I learned a couple years ago on another SHO) After I adjusted it, the RPM came down to normal for a few seconds and then went back up after I revved the engine a little. The weird thing is that the idle is NOT fluctuating at all. Isn't fluctuating normally the sign of a vacuum leak?
I drove around the block and experienced the same high idle. I was very careful when reinstalling the manifold not to drop anything! I had a friend with me to make sure that didn't happen, so I am fairly certain that nothing fell in. I know that the idle cannot be manually adjusted, but is there ANYTHING I can do to bring it down without having to take it in and hooked up to a computer???
Deven
Bizzy
SHO Member
- Joined
- May 1, 2001
- Messages
- 13,222
- Reaction score
- 1,462
Disconnect the battery and turn on the headlights to drain the power. Then follow the instructions here to reset your idle speed.
Not saying that's the problem, but it's always good to start with the more simple things.
Also, make sure you don't have anything causing the cable to be bound up or stressed.
Not saying that's the problem, but it's always good to start with the more simple things.
Also, make sure you don't have anything causing the cable to be bound up or stressed.
Dr. Tweak
Mad Scientist
Ferendon
New Member
Make sure when you hooked the throttle control actuator up, you put the tooth into the alignment hole. If it's rotated off its mark, then it could be pulling the throttle cable... Is your gas pedal sitting lower than normal?
IAC Valve?....
I had my manifold apart for a couple weeks while I was waiting for new gaskets. I put the manifold together last night and reinstalled it with the new gaskets. It idled and sounded great for the first few minutes of driving, but then went back up to 2800 RPM or so. I was extremely careful when I put the manifold back on. I also checked all the vacuum lines. I did notice that my car was running a little warmer than before also.
I hooked up the computer and this time got a code that pointed toward the IAC. I guess I will take that off and clean it. If I do need a new IAC, does anyone have one from a parts SHO or an extra laying around??? Please let me know. Thanks to everyone for your help!
Deven
I had my manifold apart for a couple weeks while I was waiting for new gaskets. I put the manifold together last night and reinstalled it with the new gaskets. It idled and sounded great for the first few minutes of driving, but then went back up to 2800 RPM or so. I was extremely careful when I put the manifold back on. I also checked all the vacuum lines. I did notice that my car was running a little warmer than before also.
I hooked up the computer and this time got a code that pointed toward the IAC. I guess I will take that off and clean it. If I do need a new IAC, does anyone have one from a parts SHO or an extra laying around??? Please let me know. Thanks to everyone for your help!
Deven
NiNeTy Fo SHO
No-mo-SHO Man
Out of curiosity, what fixed it? Fixing the cable? Resetting the idle? Fixing the throttle? Any codes?
Edit: NM...seen the other post for an IAC...
Edit: NM...seen the other post for an IAC...
Similar threads
