rev limiter help
03-20-2009, 02:24 PM
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rev limiter help
ok so i bought an acura integra that was lsvtec with a crome chipped ecu. when ur not moving it wont rev over 5g cuz of rev limiter. when it reached 8k rpm the check lite came on for a shift light, it redlined at like 8400 or so. i put a b16 in the car thanks to nitrous and lsvtec not gettin along. after that im pretty sure it still reved past 8k cuz of shift light. now it hits 7800 like its hitting a rev limiter. all ive done is put a fuel pressure gauge on it and i lowered the fuel pressure because it was running rich. anybody have any ideals. i wanna take my car to the track but id like to know the problem cuz id like to have my shiftlight
03-20-2009, 04:14 PM
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Re: rev limiter help
You may want to get the car retuned also. Your ecu you have now is running off the LS/vtec tune? If so that maybe affecting the performance of your b16
03-20-2009, 05:54 PM
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Re: rev limiter help
So you've put a fuel pressure regulator on it (I'm assuming the gauge is on a fuel pressure regulator, because a gauge can't adjust anything) and haven't done anything else to the car? You should get tuned, or at the very least get someone to make you a stock B16 program that is compatible with your ECU (if you have a P28, a stock P30 program with the knock sensor disabled will work perfectly). You're running a B16 with a tune done for an LS/VTEC, so I don't think you're going to have the best luck.
Oh, and you should put your fuel pressure back to stock when you get tuned. Lowering the fuel pressure is a horrible way to tune, and will only hurt engine performance when it actually is tuned properly. Lower pressure does nothing good when it comes to fuel atomization, etc.
Oh, and you should put your fuel pressure back to stock when you get tuned. Lowering the fuel pressure is a horrible way to tune, and will only hurt engine performance when it actually is tuned properly. Lower pressure does nothing good when it comes to fuel atomization, etc.
Last edited by Fabrik8; 03-20-2009 at 06:05 PM.
03-21-2009, 04:16 PM
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Re: rev limiter help
the reason i havnt got it tuned is becuz i have a complete turbo kit to put on and im gonna tune it then. im just wondering why my rev limiter is comin in at 7800 instead of 8200 like it used too. and my shift light (programed into check light) doesnt come till 8000 but now it wont hit 8000
03-21-2009, 04:34 PM
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Re: rev limiter help
the reason i havnt got it tuned is becuz i have a complete turbo kit to put on and im gonna tune it then. im just wondering why my rev limiter is comin in at 7800 instead of 8200 like it used too. and my shift light (programed into check light) doesnt come till 8000 but now it wont hit 8000
03-21-2009, 04:49 PM
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Re: rev limiter help
You have a working speed sensor, right?
Ok, so this may be completely wrong, but here are my thoughts. You lowered the fuel pressure, and then changed the engine. You have no idea if it is running rich or lean at high RPM around the rev limiter. I wouldn't even rev that high at all without knowing the state of the tune, but that's up to you.
So, the way rev limiters work, they usually have multiple stages based on load and RPM. The ECU has a cut sequence that will start cutting cylinders, or cutting fuel, or decreasing coil charging energy at a certain RPM. If that doesn't work, they go to a different, more aggressive cut sequence. After that, there is usually a really hard cut sequence that will just shut everything off. So the engine load and RPM dictates how much of those things that are needed to keep the engine from revving past a certain point. There are different strategies depending on what the ECU programmers decided to do.
Pretend you're some d-bag at a bar with your girl. Some guy looks at your girl, so you tell him to stop looking at your girl. He might stop. If he doesn't stop, you might get into an argument with him. If that doesn't stop him, you call your d-bag friends and get into a brawl. That's how a rev limit strategy usually works. You take action in increments until he stops looking at your girl, or you make him unable to look any more.
If it's a single stage rev limit strategy then it would be like this: Guy looks at your girl. Then he looks at your girl again. You freak out and start beating his ass with a pipe. You go from no action to 100% action.
This is what happens when I watch TV while doing project design and answering tech questions. I start making stupid analogies.
You've changed your engine to a B16 with lower intertia, and also screwed around with the fuel pressure. So because of tuning, you may not be actually getting the full rev limiter strategy from the ECU, OR you may actually be seeing what it's supposed to be doing, and the LS/VTEC wasn't getting rev limited properly. No telling. The fuel pressure might be too low, and it may not be able to overcome the higher cylinder pressure of a B16, so you might unintentionally making your own fuel cut. Who knows.
The only way to find out is to get it tuned and then you'll know what the parameters (like rev limit) are supposed to be.
Ok, so this may be completely wrong, but here are my thoughts. You lowered the fuel pressure, and then changed the engine. You have no idea if it is running rich or lean at high RPM around the rev limiter. I wouldn't even rev that high at all without knowing the state of the tune, but that's up to you.
So, the way rev limiters work, they usually have multiple stages based on load and RPM. The ECU has a cut sequence that will start cutting cylinders, or cutting fuel, or decreasing coil charging energy at a certain RPM. If that doesn't work, they go to a different, more aggressive cut sequence. After that, there is usually a really hard cut sequence that will just shut everything off. So the engine load and RPM dictates how much of those things that are needed to keep the engine from revving past a certain point. There are different strategies depending on what the ECU programmers decided to do.
Pretend you're some d-bag at a bar with your girl. Some guy looks at your girl, so you tell him to stop looking at your girl. He might stop. If he doesn't stop, you might get into an argument with him. If that doesn't stop him, you call your d-bag friends and get into a brawl. That's how a rev limit strategy usually works. You take action in increments until he stops looking at your girl, or you make him unable to look any more.
If it's a single stage rev limit strategy then it would be like this: Guy looks at your girl. Then he looks at your girl again. You freak out and start beating his ass with a pipe. You go from no action to 100% action.
This is what happens when I watch TV while doing project design and answering tech questions. I start making stupid analogies.
You've changed your engine to a B16 with lower intertia, and also screwed around with the fuel pressure. So because of tuning, you may not be actually getting the full rev limiter strategy from the ECU, OR you may actually be seeing what it's supposed to be doing, and the LS/VTEC wasn't getting rev limited properly. No telling. The fuel pressure might be too low, and it may not be able to overcome the higher cylinder pressure of a B16, so you might unintentionally making your own fuel cut. Who knows.
The only way to find out is to get it tuned and then you'll know what the parameters (like rev limit) are supposed to be.
Last edited by Fabrik8; 03-21-2009 at 05:09 PM.
03-21-2009, 05:13 PM
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Re: rev limiter help
You have a working speed sensor, right?
Ok, so this may be completely wrong, but here are my thoughts. You lowered the fuel pressure, and then changed the engine. You have no idea if it is running rich or lean at high RPM around the rev limiter. I wouldn't even rev that high at all without knowing the state of the tune, but that's up to you.
So, the way rev limiters work, they usually have multiple stages based on load and RPM. The ECU has a cut sequence that will start cutting cylinders, or cutting fuel, or decreasing coil charging energy at a certain RPM. If that doesn't work, they go to a different, more aggressive cut sequence. After that, there is usually a really hard cut sequence that will just shut everything off. So the engine load and RPM dictates how much of those things that are needed to keep the engine from revving past a certain point. There are different strategies depending on what the ECU programmers decided to do.
Pretend you're some d-bag at a bar with your girl. Some guy looks at your girl, so you tell him to stop looking at your girl. He might stop. If he doesn't stop, you might get into an argument with him. If that doesn't stop him, you call your d-bag friends and get into a brawl. That's how a rev limit strategy usually works. You take action in increments until he stops looking at your girl, or you make him unable to look any more.
If it's a single stage rev limit strategy then it would be like this: Guy looks at your girl. Then he looks at your girl again. You freak out and start beating his ass with a pipe. You go from no action to 100% action.
This is what happens when I watch TV while doing project design and answering tech questions. I start making stupid analogies.
You've changed your engine to a B16 with lower intertia, and also screwed around with the fuel pressure. So because of tuning, you may not be actually getting the full rev limiter strategy from the ECU, OR you may actually be seeing what it's supposed to be doing, and the LS/VTEC wasn't getting rev limited properly. No telling. The fuel pressure might be too low, and it may not be able to overcome the higher cylinder pressure of a B16, so you might unintentionally making your own fuel cut. Who knows.
The only way to find out is to get it tuned and then you'll know what the parameters (like rev limit) are supposed to be.
Ok, so this may be completely wrong, but here are my thoughts. You lowered the fuel pressure, and then changed the engine. You have no idea if it is running rich or lean at high RPM around the rev limiter. I wouldn't even rev that high at all without knowing the state of the tune, but that's up to you.
So, the way rev limiters work, they usually have multiple stages based on load and RPM. The ECU has a cut sequence that will start cutting cylinders, or cutting fuel, or decreasing coil charging energy at a certain RPM. If that doesn't work, they go to a different, more aggressive cut sequence. After that, there is usually a really hard cut sequence that will just shut everything off. So the engine load and RPM dictates how much of those things that are needed to keep the engine from revving past a certain point. There are different strategies depending on what the ECU programmers decided to do.
Pretend you're some d-bag at a bar with your girl. Some guy looks at your girl, so you tell him to stop looking at your girl. He might stop. If he doesn't stop, you might get into an argument with him. If that doesn't stop him, you call your d-bag friends and get into a brawl. That's how a rev limit strategy usually works. You take action in increments until he stops looking at your girl, or you make him unable to look any more.
If it's a single stage rev limit strategy then it would be like this: Guy looks at your girl. Then he looks at your girl again. You freak out and start beating his ass with a pipe. You go from no action to 100% action.
This is what happens when I watch TV while doing project design and answering tech questions. I start making stupid analogies.
You've changed your engine to a B16 with lower intertia, and also screwed around with the fuel pressure. So because of tuning, you may not be actually getting the full rev limiter strategy from the ECU, OR you may actually be seeing what it's supposed to be doing, and the LS/VTEC wasn't getting rev limited properly. No telling. The fuel pressure might be too low, and it may not be able to overcome the higher cylinder pressure of a B16, so you might unintentionally making your own fuel cut. Who knows.
The only way to find out is to get it tuned and then you'll know what the parameters (like rev limit) are supposed to be.
03-25-2009, 08:19 AM
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Re: rev limiter help
car is being retuned cuz i put my turbo kit on. it was runnin average of 12.4:1 a/f. i know this cuz i have a wideband. it was runnin richer so i droped fuel pressure for a temp fix. thanxs for all ur imput.
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