fuel
Well-known member
does your dash not have the factory LED boost gauge? On mine I find the last LED bar doesn't light until it hits 9-10psi as displayed on my boost gauge.
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I was told my turbo is not spooling?
- Thread starter kooter
- Start date
The blinky light is a dummy gauge. It doesn't read vacuum. Seems to me like it blinks according to RPM's.
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SouthCaliVR4
Well-known member
in a stock configuration the led bar gauge reads 1st three bars vacuum, & last three boost. when 825 was all stock & the turbo failed I could not get over three bars. running stock boost with a 16g & now a proper gauge indicated the same.
These days the stock bar gauge is way off but still handy if I'm keeping eye on fuel mi. as she sits, just flickering the second bar is zero anything more is boost.
These days the stock bar gauge is way off but still handy if I'm keeping eye on fuel mi. as she sits, just flickering the second bar is zero anything more is boost.
If your mechanic says it isn't spooling and you've got a pretty much stock car, remove the exhaust manifold heat shield and look for cracks in the manifold. Cracks are extremely common on a stock manifold and it can cause power loss and delay in spool up.
Also, out of curiosity, what number is your car?
kooter
Well-known member
418/2000
thank you for all the advice. Yes the stock snorkle or ducting from the stock air box is what he was talking about. I am sorry if I was using the wrong term in calling it a cold air intake. The stock guage on the cluster "night rider" lights are still there and do still move along as acceleration increases and then decreases as you cruise.
as far as I know everything on number 418 is stock.
thank you for all the advice. Yes the stock snorkle or ducting from the stock air box is what he was talking about. I am sorry if I was using the wrong term in calling it a cold air intake. The stock guage on the cluster "night rider" lights are still there and do still move along as acceleration increases and then decreases as you cruise.
as far as I know everything on number 418 is stock.
Ian M
Well-known member
Nobody can be sure how accurate your idea of "fast for a 4 cylinder" is,nor do we know what evidence your tech used in determining that your car isn't spooling so I concur with everyone else that says to get a mechanical gauge. If it's installed correctly,it will tell you what you need to know. If you plan to mod the car,you'll need it anyway. That stock LED is useless.
I actually have driven a couple high mileage cars that didn't make boost. What happened was the clip that holds the wastegate actuator rod on the flapper arm has rusted,broken and fallen out. rod slips off the pin on the arm for the flapper allowing it to be blown open constantly. In that case it won't make boost. The actuator not only opens the wastegate,it also holds it shut. It's easy to check,you don't have to take anything apart.
I actually have driven a couple high mileage cars that didn't make boost. What happened was the clip that holds the wastegate actuator rod on the flapper arm has rusted,broken and fallen out. rod slips off the pin on the arm for the flapper allowing it to be blown open constantly. In that case it won't make boost. The actuator not only opens the wastegate,it also holds it shut. It's easy to check,you don't have to take anything apart.
fuel
Well-known member
Quoting Dbossman:
The blinky light is a dummy gauge. It doesn't read vacuum. Seems to me like it blinks according to RPM's.
Really?? Mine is just about dead accurate! It only sweeps a small scale, it's entirely accurate up to where my aftermarket gauge reads 0 vac/boost and the factory LED graph is on the middle 'dot' point, and the last bar lights up at 9-10psi.
The blinky light is a dummy gauge. It doesn't read vacuum. Seems to me like it blinks according to RPM's.
Really?? Mine is just about dead accurate! It only sweeps a small scale, it's entirely accurate up to where my aftermarket gauge reads 0 vac/boost and the factory LED graph is on the middle 'dot' point, and the last bar lights up at 9-10psi.
As far as I know it gets it's signal from the ecu, not directly from a vacuum source. Mine was never good for nothing but a light show. Now that it's converted to a knock sensor threw my ECU it's useful
Barnes
Well-known member
The stock 'boost gauge' is 100% not reading out any kind of manifold vacuum/pressure. It is completely useless. Do not talk about the stock 'boost gauge' again.
Also, lets not try to trouble shoot a problem that might not exist. The original poster can get a boost gauge, install it, and report back the findings. At that point we can start doing troubleshooting.
Also, lets not try to trouble shoot a problem that might not exist. The original poster can get a boost gauge, install it, and report back the findings. At that point we can start doing troubleshooting.
yeti
Well-known member
Quoting Dbossman:
As far as I know it gets it's signal from the ecu, not directly from a vacuum source. Mine was never good for nothing but a light show. Now that it's converted to a knock sensor threw my ECU it's useful
How could I found more information on the knock sensor mod?
If you say vfag I'm going to feel real stupid.
And yeah. My stock boost gauge lights up all the way and I go no where at the moment its useless
As far as I know it gets it's signal from the ecu, not directly from a vacuum source. Mine was never good for nothing but a light show. Now that it's converted to a knock sensor threw my ECU it's useful
How could I found more information on the knock sensor mod?
If you say vfag I'm going to feel real stupid.
And yeah. My stock boost gauge lights up all the way and I go no where at the moment its useless
boostedinaz
Well-known member
Lets see if we can clear some things up.
The factory "boost gauge" doesn't read boost in any way, it simply estimates boost by taking other values from the ECU and is far from accurate. With some types of tuning software like DSMlink, Key Diver chip, or the like you can change what the "boost gauge" tells you. In my Talon I had it telling me counts of knock but it could also show other things.
The only real way to find out if your turbo is making boost is to get a real boost gauge, hook it up, and drive around to see what it says. If it doesn't show boost then your mechanic is correct if it does show boost then tell us how much and if possible how much by what RPM. Once you do that then we can help trouble shoot what ever issue you may or may not have.
For my sanity please just do this and report back. I have seen threads like this go on for weeks when peope have a simple task like this and they skip it trying this or that, talking to another mechanic, everyone here slowing straying from the original issue guessing what could be wrong etc.. This simple task will take you less than an hour and will give you a 100% concrete answer with no guessing.
The factory "boost gauge" doesn't read boost in any way, it simply estimates boost by taking other values from the ECU and is far from accurate. With some types of tuning software like DSMlink, Key Diver chip, or the like you can change what the "boost gauge" tells you. In my Talon I had it telling me counts of knock but it could also show other things.
The only real way to find out if your turbo is making boost is to get a real boost gauge, hook it up, and drive around to see what it says. If it doesn't show boost then your mechanic is correct if it does show boost then tell us how much and if possible how much by what RPM. Once you do that then we can help trouble shoot what ever issue you may or may not have.
For my sanity please just do this and report back. I have seen threads like this go on for weeks when peope have a simple task like this and they skip it trying this or that, talking to another mechanic, everyone here slowing straying from the original issue guessing what could be wrong etc.. This simple task will take you less than an hour and will give you a 100% concrete answer with no guessing.
Muskrat
Well-known member
^ It's a feature keydiver puts on his re-flashed EPROM chips. It's not something you're going to do youself, unless you have the right equipment, and the right knowledge. Some tuning packages also let you do it (ECMLink).
The stock 'boost gauge' estimates boost pressure based on the signals it's getting from the engine sensors, and magic going on inside the unit itself. It's 'junk' because it doesn't measure ACTUAL pressure. It's basically a guess, and on a stock system, with everything working correctly, it's a fairly good guess. But there's a reason it just say "-" and "+" and no real numbers.
Missed by a minute, lol.
The stock 'boost gauge' estimates boost pressure based on the signals it's getting from the engine sensors, and magic going on inside the unit itself. It's 'junk' because it doesn't measure ACTUAL pressure. It's basically a guess, and on a stock system, with everything working correctly, it's a fairly good guess. But there's a reason it just say "-" and "+" and no real numbers.
Missed by a minute, lol.
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kooter
Well-known member
I will definately do just that and report back just as soon as it is done. with the 20some inches of snow we just got might take me a little bit.
again thanks to all for the helpfullness.
again thanks to all for the helpfullness.
belize1334
Well-known member
I disagree with the "uselessness" of the factory LED gauge. That it doesn't read manifold pressure is true... what it does instead is report the calculated g/rev value which turns out to be almost exactly proportional to boost.
Now, when you install a real boost gauge it becomes redundant and is better used as a knock gauge the way most people do. But in the mean time it'll give you a ball-park figure. Anything over 3-bars and you're in boost. 6-bars and you're in the 10-12psi range.
As far as your car goes... unless the mechanic took it for a drive around the block I don't see how he'd know if the turbo was acting up. You need to be above 3k rpm with your foot in it and I don't see that happening in the parking lot. But, assuming he's right there are only a few ways in which turbo systems fail.
1) Your exhaust is escaping before the turbine and thus not spooling the turbo. This is either from a serious leak in the manifold or the housing OR because the waste-gate is hanging open as was suggested. This can be tough to diagnose... look for cracks in the manifold and make sure the wastegate actuator is connected.
2) The turbine IS getting exhaust but the turbo still isn't spooling. This means your cartridge is frozen and you need a new turbo. This is easy to diagnose by making sure the compressor wheel spins freely (with the engine off so you don't loose a finger).
3) The turbo is getting exhaust and is spinning but you're still not developing boost. This is because you have a SERIOUS leak in your charge pipes and you're venting all that air. This is easy to diagnose because you're dumping metered air and so the car will run pig-rich as it delivers fuel for air that is never making it's way to the engine.
Good luck... keep us updated.
Now, when you install a real boost gauge it becomes redundant and is better used as a knock gauge the way most people do. But in the mean time it'll give you a ball-park figure. Anything over 3-bars and you're in boost. 6-bars and you're in the 10-12psi range.
As far as your car goes... unless the mechanic took it for a drive around the block I don't see how he'd know if the turbo was acting up. You need to be above 3k rpm with your foot in it and I don't see that happening in the parking lot. But, assuming he's right there are only a few ways in which turbo systems fail.
1) Your exhaust is escaping before the turbine and thus not spooling the turbo. This is either from a serious leak in the manifold or the housing OR because the waste-gate is hanging open as was suggested. This can be tough to diagnose... look for cracks in the manifold and make sure the wastegate actuator is connected.
2) The turbine IS getting exhaust but the turbo still isn't spooling. This means your cartridge is frozen and you need a new turbo. This is easy to diagnose by making sure the compressor wheel spins freely (with the engine off so you don't loose a finger).
3) The turbo is getting exhaust and is spinning but you're still not developing boost. This is because you have a SERIOUS leak in your charge pipes and you're venting all that air. This is easy to diagnose because you're dumping metered air and so the car will run pig-rich as it delivers fuel for air that is never making it's way to the engine.
Good luck... keep us updated.
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This has all been stated by me and other's already. /ubbthreads/images/graemlins/banghead.gif Let us know when you get your boost gauge kooter.
kooter
Well-known member
belize1334
Well-known member
Barnes
Well-known member
Not sure if you noticed Belize1334, but it does have a boost gauge built in. Although I do agree, what you posted is a much better choice. We should have made the suggestion early. /ubbthreads/images/graemlins/frown.gif
kooter
Well-known member
ha its all good I figure I am gonna buy all sort's of stuff that I shouldn't.
currently have way to many plans and ideas
really into the idea of suede headliner visor's and pillars.
painting the engine bay, have the motor completely rebuild and the block and everything else possable to be powder coated.
as you can tell mostly cosmetic. I have no knowledge of turbo's or horsepower. but I look forward to learning.
One somewhat off the topic question. replacement exhaust manifold. should I just get the stock one from mitsu. or is there something else that would serve better, or have to later option for upgrades that I will get to down the rd.
currently have way to many plans and ideas
really into the idea of suede headliner visor's and pillars.
painting the engine bay, have the motor completely rebuild and the block and everything else possable to be powder coated.
as you can tell mostly cosmetic. I have no knowledge of turbo's or horsepower. but I look forward to learning.
One somewhat off the topic question. replacement exhaust manifold. should I just get the stock one from mitsu. or is there something else that would serve better, or have to later option for upgrades that I will get to down the rd.
