Idle Dips In Reverse Only
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Joined: Jul 2010
Posts: 1,756
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From: Maryland
My driveway is down hill...doesn't matter if I leave it in neutral or have it in reverse while coasting with or without the clutch depressed. Seems to happen at 3 MPH, but have not been able to make an adjustment that has made a difference.
No turns, 6M, just straight back surging between 500 - 900 RPM until stopped again. Has always done this, even before being modded, just not as bad. Frustrating.
No turns, 6M, just straight back surging between 500 - 900 RPM until stopped again. Has always done this, even before being modded, just not as bad. Frustrating.
Thread Starter
TECH Addict
Joined: Jun 2002
Posts: 2,428
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From: Las Vegas, NV
Same here Slowhawk, I tried everything as far as tuning. My last gasp is replacing the pcv hoses suggested by Justin (arriving today). Luckily this reverse thing isn't a major problem, just a minor inconvenience.
Thread Starter
TECH Addict
Joined: Jun 2002
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From: Las Vegas, NV
I installed the new pcv valve and hose and the idle and reverse situation is much improved. It's a subtle difference with the idle overall, but the first thing I noticed is that the gauge needle stays pegged, no movement at all, at the commanded rpm. Idle shifting into reverse is much improved as well the one time I tested it and was the reason for this thread.
I feel silly having asked for tuning help when it was a mechanical problem all along, sorry about that. Thanks to everyone who posted, it was all helpful, and especially to Justin who nailed the problem, thanks!
I feel silly having asked for tuning help when it was a mechanical problem all along, sorry about that. Thanks to everyone who posted, it was all helpful, and especially to Justin who nailed the problem, thanks!
Thread Starter
TECH Addict
Joined: Jun 2002
Posts: 2,428
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From: Las Vegas, NV
I thought I had my idle dip problem (reverse mostly) solved with new pcv hoses, but I didn't test drive enough to draw that conclusion. It turns out that it was a tuning problem afterall. This is really dumb but I had just blindly followed the rule-of-thumb of taking fuel out of the 400, 800, and 1200 rpm columns in the VE table by multiplying by 60, 80, and 90 percent. I tried decreasing the amount of fuel removal by multiplying by 85, 90, and 95 percent and no more idle dips under any circumstances. It makes perfect sense because I just have a small cam (TR 224/ 224 112 LSA) and the more aggressive fuel removal is to solve problems for bigger cams.
The only other changes to my idle tuning are 2 degrees of timing advance in the idle region; +1 across the board in the Base Running Idle Airflow table, and a minor bump to 825 rpms for idle. Simple and effective with great results for my setup.
The only other changes to my idle tuning are 2 degrees of timing advance in the idle region; +1 across the board in the Base Running Idle Airflow table, and a minor bump to 825 rpms for idle. Simple and effective with great results for my setup.
Launching!
Joined: Apr 2019
Posts: 206
Likes: 11
From: Bay area
[QUOTE=Predator;15841088]I thought I had my idle dip problem (reverse mostly) solved with new pcv hoses, but I didn't test drive enough to draw that conclusion. It turns out that it was a tuning problem afterall. This is really dumb but I had just blindly followed the rule-of-thumb of taking fuel out of the 400, 800, and 1200 rpm columns in the VE table by multiplying by 60, 80, and 90 percent. I tried decreasing the amount of fuel removal by multiplying by 85, 90, and 95 percent and no more idle dips under any circumstances. It makes perfect sense because I just have a small cam (TR 224/ 224 112 LSA) and the more aggressive fuel removal is to solve problems for bigger cams.
The only other changes to my idle tuning are 2 degrees of timing advance in the idle region; +1 across the board in the Base Running Idle Airflow table, and a minor bump to 825 rpms for idle. Simple and effective with great results for my setup.[/QUOTE
Is a
I know this tread is kinda old but it seem like I'm having the exact same issue lol. Ever since the cam installed it's been doing it. I just recently received my other pcm from my tuner and it still does it. Just the other day it's stall while reversing. Other then that it's idles perfect at 750 in drive and park. Occasionally in reverse it idle OK, but most times it seem like it about to stall out. My tuner did mention to do the tps reset procedure. If anybody can tell how to do it, much appreciate.
The only other changes to my idle tuning are 2 degrees of timing advance in the idle region; +1 across the board in the Base Running Idle Airflow table, and a minor bump to 825 rpms for idle. Simple and effective with great results for my setup.[/QUOTE
Is a
I know this tread is kinda old but it seem like I'm having the exact same issue lol. Ever since the cam installed it's been doing it. I just recently received my other pcm from my tuner and it still does it. Just the other day it's stall while reversing. Other then that it's idles perfect at 750 in drive and park. Occasionally in reverse it idle OK, but most times it seem like it about to stall out. My tuner did mention to do the tps reset procedure. If anybody can tell how to do it, much appreciate.
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Brett Foote Launching!
Joined: Apr 2019
Posts: 206
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From: Bay area
wsup bro why you trolling? You have nothing to do with your life? I'm just asking a simple questions that's it, there no need for negatively. If you don't got no good info that not gonna help me out, then say less. Go somewhere and BTW it's not the tuner fault it's something everybody has to do when it's comes to these motor.
TECH Senior Member
Joined: Jun 2016
Posts: 22,290
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From: Central Cal.
Not trolling at all. If your tuner can't or won't tell you how to do a re-learn, what is he good for? It's like asking a chef to boil an egg. He mentioned you should do it. He should be able to tell you how. Why seek advice on the internet when you have a good source at hand?? Common sense to me...
Launching!
Joined: Apr 2019
Posts: 206
Likes: 11
From: Bay area
Not trolling at all. If your tuner can't or won't tell you how to do a re-learn, what is he good for? It's like asking a chef to boil an egg. He mentioned you should do it. He should be able to tell you how. Why seek advice on the internet when you have a good source at hand?? Common sense to me...
TECH Senior Member
Joined: Jun 2016
Posts: 22,290
Likes: 3,615
From: Central Cal.
I am here to dispense any good info that I have knowledge of.
Back to the subject, WHY can't your tuner tell you how to do the relearn, since he advised you to do it? When someone needs help, that someone asks a qualified person about it. You know a qualified person, your tuner. Is there a reason you can't ask him?? So far you have avoided answering that question, which I have asked in every post in this thread.
Don't get philosophical, please answer the question.
Back to the subject, WHY can't your tuner tell you how to do the relearn, since he advised you to do it? When someone needs help, that someone asks a qualified person about it. You know a qualified person, your tuner. Is there a reason you can't ask him?? So far you have avoided answering that question, which I have asked in every post in this thread.
Don't get philosophical, please answer the question.
Launching!
Joined: Apr 2019
Posts: 206
Likes: 11
From: Bay area
I am here to dispense any good info that I have knowledge of.
Back to the subject, WHY can't your tuner tell you how to do the relearn, since he advised you to do it? When someone needs help, that someone asks a qualified person about it. You know a qualified person, your tuner. Is there a reason you can't ask him?? So far you have avoided answering that question, which I have asked in every post in this thread.
Don't get philosophical, please answer the question.
Back to the subject, WHY can't your tuner tell you how to do the relearn, since he advised you to do it? When someone needs help, that someone asks a qualified person about it. You know a qualified person, your tuner. Is there a reason you can't ask him?? So far you have avoided answering that question, which I have asked in every post in this thread.
Don't get philosophical, please answer the question.
Launching!
Joined: Apr 2019
Posts: 206
Likes: 11
From: Bay area
[QUOTE=G Atsma;20178396]OK, now you have an explanation. He has a life, and something like this would not take more than 5 minutes out of his day. Barring that, have you googled it?[/QUOTE ]it ain't that simple, he lives in Connecticut, I live in California. This was mail-order tune. Sorry I didn't mention that in the first place and yes I Google it, that why I'm here lol.
Last edited by LT1DG; Dec 1, 2019 at 01:18 AM.
TECH Senior Member
Joined: Jun 2016
Posts: 22,290
Likes: 3,615
From: Central Cal.
I don't have the answer as I didn't google it, which you COULD have done the whole time, as I suggested, instead of waiting for it here.
PLUS, you never said it was a mail order tune until lately, only that you had a "tuner", which gave the impression you got it tuned someplace, which led me to believe you actually knew the guy. I did not have a few important details that could have shortened this whole deal.
PLUS, you never said it was a mail order tune until lately, only that you had a "tuner", which gave the impression you got it tuned someplace, which led me to believe you actually knew the guy. I did not have a few important details that could have shortened this whole deal.
Launching!
Joined: Apr 2019
Posts: 206
Likes: 11
From: Bay area
I don't have the answer as I didn't google it, which you COULD have done the whole time, as I suggested, instead of waiting for it here.
PLUS, you never said it was a mail order tune until lately, only that you had a "tuner", which gave the impression you got it tuned someplace, which led me to believe you actually knew the guy. I did not have a few important details that could have shortened this whole deal.
PLUS, you never said it was a mail order tune until lately, only that you had a "tuner", which gave the impression you got it tuned someplace, which led me to believe you actually knew the guy. I did not have a few important details that could have shortened this whole deal.
Why would you need to do a TPS relearn? Are you at 4% with the throttle closed or something?
If it's dying when you are backing up, either fuel is off or your IAC is off. If you have an aftermarket TB, the IAC counts are all wrong I'm sure, and the IAC motor is not stepping correctly to keep the engine RPM stable.
Of course, it's a bit of balancing act to get the throttle blade open enough and then tuning the IAC transfer table correctly.
If however, you have a stock TB, then it's simply the fueling is off in idle. And you may need some more airflow in your follower table to offset the cam.
Btw, these are all shots in the dark. I have no idea what your combo is. And just because it idles rock solid doesn't mean anything. It's the return to idle, maintaining idle when you turn the steering wheel, etc. that determine if your idle tuning is any good.
If it's dying when you are backing up, either fuel is off or your IAC is off. If you have an aftermarket TB, the IAC counts are all wrong I'm sure, and the IAC motor is not stepping correctly to keep the engine RPM stable.
Of course, it's a bit of balancing act to get the throttle blade open enough and then tuning the IAC transfer table correctly.
If however, you have a stock TB, then it's simply the fueling is off in idle. And you may need some more airflow in your follower table to offset the cam.
Btw, these are all shots in the dark. I have no idea what your combo is. And just because it idles rock solid doesn't mean anything. It's the return to idle, maintaining idle when you turn the steering wheel, etc. that determine if your idle tuning is any good.