Idle question
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I've never used a Modern Musclecar chip, but they've been doing Turbo Buicks (Mike Licht / now called Ramchargers) for a long time.
Let us know what you find out on DirectScan. The 009 injectors are kind of weird right off idle. I have them on my 87GN using a Red Armstrong 93 chip....I had to remove one MAF screen to get rid of an off-idle stumble. Runs great now.
I'm assuming this is on the GNX you list in your sig.....you're a brave man modifying a GNX!
I'm up in Pryor....East of Tulsa. I have family in El Reno and make it to Thunder Valley every once and a while. Were you at the Shootout last fall?
Good Luck,
John
Let us know what you find out on DirectScan. The 009 injectors are kind of weird right off idle. I have them on my 87GN using a Red Armstrong 93 chip....I had to remove one MAF screen to get rid of an off-idle stumble. Runs great now.
I'm assuming this is on the GNX you list in your sig.....you're a brave man modifying a GNX!
I'm up in Pryor....East of Tulsa. I have family in El Reno and make it to Thunder Valley every once and a while. Were you at the Shootout last fall?
Good Luck,
John
It's the throtle follower function of the IAC.
It's to prevent stalling.
Everytime you crack the gas you'll see the IAC jump up a little, then deacy back to *normal* at idle.
You'll also see a max posistion at WOT of like 150+.
This function can vary as a matter of what the programmer wants.
It's to prevent stalling.
Everytime you crack the gas you'll see the IAC jump up a little, then deacy back to *normal* at idle.
You'll also see a max posistion at WOT of like 150+.
This function can vary as a matter of what the programmer wants.
Okay, I finally got the DS hooked up and saved some files. By the way, I hate tuning this thing!! Anyway, what numbers do you guys need? I'm encountering another problem (I think). I'm running 44psi fp with hose off, but I can't adjust it any lower. I'm also getting 2.3 deg of retard with 101 octane.
John,
After you replied to my post I noticed that you're in the OK Buick club. I'm sure I've seen you before. You can look at it that I'm either brave or stupid for modifying a GNX. I had the GNX at the shootout the last three years. Each year I'm progressively getting quicker, but I think I've hit a tuning wall.
Thanks for your help,
John,
After you replied to my post I noticed that you're in the OK Buick club. I'm sure I've seen you before. You can look at it that I'm either brave or stupid for modifying a GNX. I had the GNX at the shootout the last three years. Each year I'm progressively getting quicker, but I think I've hit a tuning wall.
Thanks for your help,
Brandon,
The things to look at when you think your idle is funny are (obviously) idle RPM, which the chip controls...usually 750-775 RPM. The IAC #'s at idle should be 10-30 with the car in P/N and everything up to temp (160-170 degF). Your idle TPS voltage should be .40-.45 volts. Idle BLM should be close to 128...higher than 128 means that the computer is adding fuel therefore it's a bit lean (usually a vacuum leak somewhere)....lower than 128 means it taking fuel out and you're a bit rich. Also look at the MAF # at idle...should be between 4 and 6. Take a look at the O2 cross counts and make sure the O2 sensor is active....the O2 millivolt readings will be jumping all around and this is normal for a closed loop idle.
If all these numbers are within range the idle is probably as good as it will get unless you have something else wrong like bad wires / coil pack / fouled plugs / etc.
If you can't adjust your fuel pressure down, even though the 44 psi is going to be pretty close to what you need, it may indicate a problem with the FP regulator. I would hook up a hot wire to the fuel pump test lead behind the alternator and get a MityVac to hook up to the vacuum line on the top of the regulator....you can pump the MityVac up to...say 10 lbs...and confirm that the regulator is adding 10 psi of fuel pressure....
Yeah...I remember your car. I did a double take on it two years ago at the Shootout. It was parked south of the consession stand over by the burgandy beast that Conley had there. I didn't pay too much attention to the badging and the fender vents until I looked under the hood and saw the GNX intercooler. I stopped myself mid sentence saying "wow, they even put a GNX intercooler on it" (thinking it was a clone). Hmmmmm walked around to the back of it and peeked under the back bumper....NO KIDDING. This guy is racing his GNX! COOOOOOL.
Good Luck and let us know how it goes,
John
The things to look at when you think your idle is funny are (obviously) idle RPM, which the chip controls...usually 750-775 RPM. The IAC #'s at idle should be 10-30 with the car in P/N and everything up to temp (160-170 degF). Your idle TPS voltage should be .40-.45 volts. Idle BLM should be close to 128...higher than 128 means that the computer is adding fuel therefore it's a bit lean (usually a vacuum leak somewhere)....lower than 128 means it taking fuel out and you're a bit rich. Also look at the MAF # at idle...should be between 4 and 6. Take a look at the O2 cross counts and make sure the O2 sensor is active....the O2 millivolt readings will be jumping all around and this is normal for a closed loop idle.
If all these numbers are within range the idle is probably as good as it will get unless you have something else wrong like bad wires / coil pack / fouled plugs / etc.
If you can't adjust your fuel pressure down, even though the 44 psi is going to be pretty close to what you need, it may indicate a problem with the FP regulator. I would hook up a hot wire to the fuel pump test lead behind the alternator and get a MityVac to hook up to the vacuum line on the top of the regulator....you can pump the MityVac up to...say 10 lbs...and confirm that the regulator is adding 10 psi of fuel pressure....
Yeah...I remember your car. I did a double take on it two years ago at the Shootout. It was parked south of the consession stand over by the burgandy beast that Conley had there. I didn't pay too much attention to the badging and the fender vents until I looked under the hood and saw the GNX intercooler. I stopped myself mid sentence saying "wow, they even put a GNX intercooler on it" (thinking it was a clone). Hmmmmm walked around to the back of it and peeked under the back bumper....NO KIDDING. This guy is racing his GNX! COOOOOOL.
Good Luck and let us know how it goes,
John
I think OK hit it on the head. I bet your TPS is .46v or better. Get it under .46
Also some chips have some "dashpot" built in, in that they will bring the idle down at a certain rate. Maybe this is the case with your chip
Also some chips have some "dashpot" built in, in that they will bring the idle down at a certain rate. Maybe this is the case with your chip
You got it! After warming up the car the TPS was fluctuating between .48-.50. I'll adjust that down on Sat.
All of these are pretty close. Idle is a little higher, but that's probably due to the high TPS. BLM is 118, IAC is 33, and MAF is 6. I'll jack with my fp regulator and adjust the tps and see what I come up with then.
Thanks for all your help guys!
See...that wasn't too bad now was it....
I would be very careful if the FP regulator is acting funky. You don't want it to go lean at WOT and blow up that GNX.
Do you have a MityVac tool? It will allow you to check the FP reg. for a vacuum leak, and also check that it is adding 1 psi of FP for every 1 psi of boost. (You'll need to get the MityVac kit that does pressure AND vacuum)
You think these things are hard to tune....I used to be into old Triumph motorcycles. I sold my last one about 6 months ago. It was a '72 Trident (3 cylinder).....three coils / three sets of points / three finicky AMAL carburetors / and it didn't like to run on the "new" gas. But boy did it look and sound cool. I would spend HOURS playing around with the points trying to get them all gapped and dwelling correctly. Most of the time I would just give up after an hour and go for a ride. It basically has three separate ignition systems all trying to work at the same time.
Lucas....the prince of darkness.
Oh well, talk at ya later,
John
I would be very careful if the FP regulator is acting funky. You don't want it to go lean at WOT and blow up that GNX.
Do you have a MityVac tool? It will allow you to check the FP reg. for a vacuum leak, and also check that it is adding 1 psi of FP for every 1 psi of boost. (You'll need to get the MityVac kit that does pressure AND vacuum)
You think these things are hard to tune....I used to be into old Triumph motorcycles. I sold my last one about 6 months ago. It was a '72 Trident (3 cylinder).....three coils / three sets of points / three finicky AMAL carburetors / and it didn't like to run on the "new" gas. But boy did it look and sound cool. I would spend HOURS playing around with the points trying to get them all gapped and dwelling correctly. Most of the time I would just give up after an hour and go for a ride. It basically has three separate ignition systems all trying to work at the same time.
Lucas....the prince of darkness.
Oh well, talk at ya later,
John
John,
Well I tested my fp regulator with my "modified" mighty vac pump. Wow! With 10 psi on the regulator it increased fuel pressure by one whole pound. No wonder I'm getting sky high egt temps and knock @ 17 psi of boost. Do you know if you can rebuild billet fp regulators? I'll start a new thread and see if it can be done.
Triumph Motorcycles!
Do you know Tom Keith form the OKC area? He has the ECGN. I think he's into Triumphs also.
Anyhow, thanks again for your help. I'll keep you posted on how my idle problem plays out.
Well I tested my fp regulator with my "modified" mighty vac pump. Wow! With 10 psi on the regulator it increased fuel pressure by one whole pound. No wonder I'm getting sky high egt temps and knock @ 17 psi of boost. Do you know if you can rebuild billet fp regulators? I'll start a new thread and see if it can be done.
Triumph Motorcycles!
Do you know Tom Keith form the OKC area? He has the ECGN. I think he's into Triumphs also.
Anyhow, thanks again for your help. I'll keep you posted on how my idle problem plays out.
