92 LT1, sputtering bad
Thread Starter
Cruising
Joined: Jul 2014
Posts: 10
Likes: 0
From: Rhode island
92 LT1, sputtering bad
Hello, first time here and new to this, couple of days ago my car would start to sputter on acceleration only a couple of times, then ran fine.
stopped to get gas and when I started it up and took off it was nothing but sputtering, is it safe to say the optispark is shot?? sounds like its running on every other cyl. I read up on how to jump the obd for the codes, will that tell me the problem?? , car has 126,000 I would have to think its the original optispark
thanks
stopped to get gas and when I started it up and took off it was nothing but sputtering, is it safe to say the optispark is shot?? sounds like its running on every other cyl. I read up on how to jump the obd for the codes, will that tell me the problem?? , car has 126,000 I would have to think its the original optispark
thanks
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Well, it could be the opti spark...but then it could be...
Fuel pressure regulator
Fuel filter clogged
Fuel pump
Bad Gas
IAC
ICM
Coil
Bad plugs
Bad wires
Loose ground
You get the idea.
It requires proper diagnosis to discover the problem.
Fuel pressure regulator
Fuel filter clogged
Fuel pump
Bad Gas
IAC
ICM
Coil
Bad plugs
Bad wires
Loose ground
You get the idea.
It requires proper diagnosis to discover the problem.
Thread Starter
Cruising
Joined: Jul 2014
Posts: 10
Likes: 0
From: Rhode island
sheeeesh
I was kind off hoping that it was more narrowed down to one thing, there was never any issues at all with the car this all happened within like 2 days so It kinda seems like its more off a mechanical problem, like and optispark, but I have never had to deal with one until now, so not really sure of the symptoms of one other than thinking misfiring.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
good god,
I was kind off hoping that it was more narrowed down to one thing, there was never any issues at all with the car this all happened within like 2 days so It kinda seems like its more off a mechanical problem, like and optispark, but I have never had to deal with one until now, so not really sure of the symptoms of one other than thinking misfiring.
I was kind off hoping that it was more narrowed down to one thing, there was never any issues at all with the car this all happened within like 2 days so It kinda seems like its more off a mechanical problem, like and optispark, but I have never had to deal with one until now, so not really sure of the symptoms of one other than thinking misfiring.
Fuel pressure regulator, located at the back of the fuel rail on the drivers side. It is a cannister with a black vacuum hose coming out of it. Pull that hose and see if it has fuel in/on it. If there is any gas at all, it's bad.
Second, go to Autozone, or any major parts store, and rent a fuel pressure gauge. Check your fuel pressure using the schreader valve near the regulator. If it's low, below 38-42 psi, then you have either a clogged filter and/or your fuel pump is going south.
Spark, first pull the car into the garage, or wait for it to get dark. Remove the hood light fuse, located near the driver side headlight, and look for arching from your plug wires.
Next, and get one while your at the parts store, rent/buy a spark tester. Check for spark at the plugs. If you do not have spark at the plugs then check for spark at the coil wire at the opti connection. If you have spark there, then you have a bad opti. If you do not have spark there, then check for spark coming from the coil, at the coil. If you do not have spark there, get a 7mm socket and remove the ICM, it is the thing plugged in just above the coil. Take it to the parts store when you return the rented tools, and they can check it for you. This part fails when the heat sink grease on the back wears thin and it overheats. Note about the coil wire, if you have spark at the coil, but going into the opti, then you could have a bad coil wire. It lives in a rough neighborhood, they go bad sometimes.
If your spark checks out, then it's back to fuel, or fuel management. If the pressure and the regulator checked out, then you're looking at IAC (idle air control) or the injectors. There are a couple of ways to check the injectors, try a search in this forum and you'll get the specs pretty easily. The iac controls the amount of air let in at idle when the TB blade is closed. It is basically a spring device on the side of the throttle body. These can get gummed up, it's easy to remove and can be cleaned with some brake cleaner.
Something else that should not be overlooked are the catalytic converters. If these burn up, they either break up into pieces and rattle. Or worse, they melt, and clog up the exhaust, creating back pressure which will cause the engine to run like crap. Sometimes you can tell by checking out the exhaust at the rear of the car, or if the pipes in front of the cats are getting alot hotter than they should be.
Also see if the parts store has a code scanner that is OBDI compatible. If you are having converter issues, maf sensor issues, O2 sensor issues, misfire issues, it will lead you in that direction.
Of course there a few other things it could be, but I've written a wall of text already, and most of those are more longshot things, whereas what I've listed are the more common on a 20+ year old car.
Thread Starter
Cruising
Joined: Jul 2014
Posts: 10
Likes: 0
From: Rhode island
So it probably is one thing causing it. I like to start with the simplest things first, based upon the symptom.
Fuel pressure regulator, located at the back of the fuel rail on the drivers side. It is a cannister with a black vacuum hose coming out of it. Pull that hose and see if it has fuel in/on it. If there is any gas at all, it's bad.
Second, go to Autozone, or any major parts store, and rent a fuel pressure gauge. Check your fuel pressure using the schreader valve near the regulator. If it's low, below 38-42 psi, then you have either a clogged filter and/or your fuel pump is going south.
Spark, first pull the car into the garage, or wait for it to get dark. Remove the hood light fuse, located near the driver side headlight, and look for arching from your plug wires.
Next, and get one while your at the parts store, rent/buy a spark tester. Check for spark at the plugs. If you do not have spark at the plugs then check for spark at the coil wire at the opti connection. If you have spark there, then you have a bad opti. If you do not have spark there, then check for spark coming from the coil, at the coil. If you do not have spark there, get a 7mm socket and remove the ICM, it is the thing plugged in just above the coil. Take it to the parts store when you return the rented tools, and they can check it for you. This part fails when the heat sink grease on the back wears thin and it overheats. Note about the coil wire, if you have spark at the coil, but going into the opti, then you could have a bad coil wire. It lives in a rough neighborhood, they go bad sometimes.
If your spark checks out, then it's back to fuel, or fuel management. If the pressure and the regulator checked out, then you're looking at IAC (idle air control) or the injectors. There are a couple of ways to check the injectors, try a search in this forum and you'll get the specs pretty easily. The iac controls the amount of air let in at idle when the TB blade is closed. It is basically a spring device on the side of the throttle body. These can get gummed up, it's easy to remove and can be cleaned with some brake cleaner.
Something else that should not be overlooked are the catalytic converters. If these burn up, they either break up into pieces and rattle. Or worse, they melt, and clog up the exhaust, creating back pressure which will cause the engine to run like crap. Sometimes you can tell by checking out the exhaust at the rear of the car, or if the pipes in front of the cats are getting alot hotter than they should be.
Also see if the parts store has a code scanner that is OBDI compatible. If you are having converter issues, maf sensor issues, O2 sensor issues, misfire issues, it will lead you in that direction.
Of course there a few other things it could be, but I've written a wall of text already, and most of those are more longshot things, whereas what I've listed are the more common on a 20+ year old car.
Fuel pressure regulator, located at the back of the fuel rail on the drivers side. It is a cannister with a black vacuum hose coming out of it. Pull that hose and see if it has fuel in/on it. If there is any gas at all, it's bad.
Second, go to Autozone, or any major parts store, and rent a fuel pressure gauge. Check your fuel pressure using the schreader valve near the regulator. If it's low, below 38-42 psi, then you have either a clogged filter and/or your fuel pump is going south.
Spark, first pull the car into the garage, or wait for it to get dark. Remove the hood light fuse, located near the driver side headlight, and look for arching from your plug wires.
Next, and get one while your at the parts store, rent/buy a spark tester. Check for spark at the plugs. If you do not have spark at the plugs then check for spark at the coil wire at the opti connection. If you have spark there, then you have a bad opti. If you do not have spark there, then check for spark coming from the coil, at the coil. If you do not have spark there, get a 7mm socket and remove the ICM, it is the thing plugged in just above the coil. Take it to the parts store when you return the rented tools, and they can check it for you. This part fails when the heat sink grease on the back wears thin and it overheats. Note about the coil wire, if you have spark at the coil, but going into the opti, then you could have a bad coil wire. It lives in a rough neighborhood, they go bad sometimes.
If your spark checks out, then it's back to fuel, or fuel management. If the pressure and the regulator checked out, then you're looking at IAC (idle air control) or the injectors. There are a couple of ways to check the injectors, try a search in this forum and you'll get the specs pretty easily. The iac controls the amount of air let in at idle when the TB blade is closed. It is basically a spring device on the side of the throttle body. These can get gummed up, it's easy to remove and can be cleaned with some brake cleaner.
Something else that should not be overlooked are the catalytic converters. If these burn up, they either break up into pieces and rattle. Or worse, they melt, and clog up the exhaust, creating back pressure which will cause the engine to run like crap. Sometimes you can tell by checking out the exhaust at the rear of the car, or if the pipes in front of the cats are getting alot hotter than they should be.
Also see if the parts store has a code scanner that is OBDI compatible. If you are having converter issues, maf sensor issues, O2 sensor issues, misfire issues, it will lead you in that direction.
Of course there a few other things it could be, but I've written a wall of text already, and most of those are more longshot things, whereas what I've listed are the more common on a 20+ year old car.
Thank you again enjoy your weekend
