Cannot rev. past 4500 part 2... (this time with Datamaster)
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Cannot rev. past 4500 part 2... (this time with Datamaster)
Hi :seeya
heres part one http://forums.corvetteforum.com/zerothread?id=599484
So today i got my Fuel Pressure gauge but it had no fitting for the schraeder valve. So i hooked it up right after the fuel pump using a T pipe. After the lines were primed it had 44.1 psi. After startup 35.8 psi and when at WOT @ 4200 rpms :cry - 42.4 psi. Is this normal??
It was a slow day at work today so i went to radio shack on my lunch break and bought the parts for an ALDL -> rs232 converter and soldered it together in my office :lol: it works like a charm! :thumbs: So now i have recorded som data in TTSs Datamaster -I can e-mail it to whom ever wants it or if someone here could host it, I would be very greatfull..
Thanks alot for helping!
I'm shure that the minds on this forum can cure my baby!
btw: sorry for the poor spelling...
:cheers:
Daniel
heres part one http://forums.corvetteforum.com/zerothread?id=599484
So today i got my Fuel Pressure gauge but it had no fitting for the schraeder valve. So i hooked it up right after the fuel pump using a T pipe. After the lines were primed it had 44.1 psi. After startup 35.8 psi and when at WOT @ 4200 rpms :cry - 42.4 psi. Is this normal??
It was a slow day at work today so i went to radio shack on my lunch break and bought the parts for an ALDL -> rs232 converter and soldered it together in my office :lol: it works like a charm! :thumbs: So now i have recorded som data in TTSs Datamaster -I can e-mail it to whom ever wants it or if someone here could host it, I would be very greatfull..
Thanks alot for helping!
I'm shure that the minds on this forum can cure my baby!
btw: sorry for the poor spelling...
:cheers:
Daniel
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: Cannot rev. past 4500 part 2... (Daniel DK)
:confused: So far I don't see anything wrong:
- good vacuum
- Sterms look good
- Injector duty cycle looks weird, 95% at 5000 rpm sounds kinda high
Maybe you have some bad injectors or fuel pressure regulator.
- good vacuum
- Sterms look good
- Injector duty cycle looks weird, 95% at 5000 rpm sounds kinda high
Maybe you have some bad injectors or fuel pressure regulator.
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: Cannot rev. past 4500 part 2... (Timmy!)
Is your car stock? That injector duty cycle is way too high for a stock car. I have a 383 in my car running stock injectors and hardly reach that.
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: Cannot rev. past 4500 part 2... (Timmy!)
Sorry - just throwing these out there as I review it. Looks like your car is running on the rich side at idle, does it smell rich? You've got STerms at idle that are 64 and 69 :eek: They should be 128 anything less is rich, anything more is lean. You might have an injector that is stuck open or something.
[Modified by Timmy!, 3:38 PM 7/11/2003]
[Modified by Timmy!, 3:38 PM 7/11/2003]
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Timmy!)
:confused: So far I don't see anything wrong:
- good vacuum
- Sterms look good
- Injector duty cycle looks weird, 95% at 5000 rpm sounds kinda high
Maybe you have some bad injectors or fuel pressure regulator.
- good vacuum
- Sterms look good
- Injector duty cycle looks weird, 95% at 5000 rpm sounds kinda high
Maybe you have some bad injectors or fuel pressure regulator.
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: Cannot rev. past 4500 part 2... (Daniel DK)
That is at WOT in neutral ... when i do that cloud of black smoke is pushed out.. so you are saying that i'm WAAAY rich??
[Modified by Timmy!, 3:48 PM 7/11/2003]
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Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Timmy!)
[QUOTE]That is at WOT in neutral ... when i do that cloud of black smoke is pushed out.. so you are saying that i'm WAAAY rich??
WAAAY Rich is an understatement! Rich is 2% less than 128, so 125 would be rich and you are at 64! Your fuel pressure is right where it needs to be so I my best guess is that you have a bad injector(s).
/[QUOTE]
:eek:Dayyamn! ok - ive - done the screwdrivertotehear thing and they are alle ticking... also the system holds fuel pressure for at least an hour at 35 psi. How du I test them?? - put them in a bucket and crank??
what value are the o2s supposed to have at idle?? are the system adjusting the Sterm based on o2s??
I do have a Unichip piggyback computer... also there is an aftermarket exhaust system. Both cats removed and one large is installed after the Y-pipe...
WAAAY Rich is an understatement! Rich is 2% less than 128, so 125 would be rich and you are at 64! Your fuel pressure is right where it needs to be so I my best guess is that you have a bad injector(s).
/[QUOTE]
:eek:Dayyamn! ok - ive - done the screwdrivertotehear thing and they are alle ticking... also the system holds fuel pressure for at least an hour at 35 psi. How du I test them?? - put them in a bucket and crank??
what value are the o2s supposed to have at idle?? are the system adjusting the Sterm based on o2s??
I do have a Unichip piggyback computer... also there is an aftermarket exhaust system. Both cats removed and one large is installed after the Y-pipe...
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Timmy!)
I measured the FP on top of the fuel tank right after the Fuel pump using a T fitting - by doing that did i also test the FP-regulator or do i need to measure at the Schreader valve for that?
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Timmy!)
That is at WOT in neutral ... when i do that cloud of black smoke is pushed out.. so you are saying that i'm WAAAY rich??
WAAAY Rich is an understatement! Rich is 2% less than 128, so 125 would be rich and you are at 64! Your fuel pressure is right where it needs to be so I my best guess is that you have a bad injector(s).
[Modified by Timmy!, 3:48 PM 7/11/2003]
WAAAY Rich is an understatement! Rich is 2% less than 128, so 125 would be rich and you are at 64! Your fuel pressure is right where it needs to be so I my best guess is that you have a bad injector(s).
[Modified by Timmy!, 3:48 PM 7/11/2003]
is this correct?
[Modified by Daniel DK, 12:15 AM 7/12/2003]
Pro
Joined: Aug 2000
Posts: 700
Likes: 1
From: Florida
Re: Cannot rev. past 4500 part 2... (Daniel DK)
Dan
At WOT.. The O2 sensors are ignored by the ECM. At that point, certain static values are read (cells) that determine the amount fuel to deliver. Esentialy determining the amount of time the injectors stay open.
Hank
:auto:
At WOT.. The O2 sensors are ignored by the ECM. At that point, certain static values are read (cells) that determine the amount fuel to deliver. Esentialy determining the amount of time the injectors stay open.
Hank
:auto:
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Cannot rev. past 4500 part 2... (93LT1)
Dude
I had the SAME EXACT problem. The car idles great and had good part throttle but choked around 4000RPM. I trouble shot everything for weeks! I could recite you the wire colors on the back of the ECM after days of probing for signals!!!
I was sitting behind the car while it was idling and my son (12 Year old) snapped the throttle open to hear the eng rev. :rolleyes:
I noticed that the exhaust sounded normal until the rpm came up and then it sounded like it was being chocked off.
LONG STORY SHORT! :D The CAT was just about plugged solid. I changed the CAT and she ran like a scalded Cat!!!!!
I would just unbolt the cat and see if that changes the way she runs. :thumbs: I bet that is your problem.
If it is, I would get a good high flow unit.
Bill C
I had the SAME EXACT problem. The car idles great and had good part throttle but choked around 4000RPM. I trouble shot everything for weeks! I could recite you the wire colors on the back of the ECM after days of probing for signals!!!
I was sitting behind the car while it was idling and my son (12 Year old) snapped the throttle open to hear the eng rev. :rolleyes:
I noticed that the exhaust sounded normal until the rpm came up and then it sounded like it was being chocked off.
LONG STORY SHORT! :D The CAT was just about plugged solid. I changed the CAT and she ran like a scalded Cat!!!!!
I would just unbolt the cat and see if that changes the way she runs. :thumbs: I bet that is your problem.
If it is, I would get a good high flow unit.
Bill C
Race Director
Joined: Aug 2002
Posts: 13,356
Likes: 0
From: tucson AZ
St. Jude Donor '04 & '05
Re: Cannot rev. past 4500 part 2... (Daniel DK)
Sounds like my crossfire....ie: starving for air........4500rpm, then dump.........
Just my simple thoughts...
tony
:smash:
[Modified by oldace84, 5:50 PM 7/12/2003]
[Modified by oldace84, 5:51 PM 7/12/2003]
Just my simple thoughts...
tony
:smash:
[Modified by oldace84, 5:50 PM 7/12/2003]
[Modified by oldace84, 5:51 PM 7/12/2003]
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Bill Curlee)
Dude
I had the SAME EXACT problem. The car idles great and had good part throttle but choked around 4000RPM. I trouble shot everything for weeks! I could recite you the wire colors on the back of the ECM after days of probing for signals!!!
I was sitting behind the car while it was idling and my son (12 Year old) snapped the throttle open to hear the eng rev. :rolleyes:
I noticed that the exhaust sounded normal until the rpm came up and then it sounded like it was being chocked off.
LONG STORY SHORT! :D The CAT was just about plugged solid. I changed the CAT and she ran like a scalded Cat!!!!!
I would just unbolt the cat and see if that changes the way she runs. :thumbs: I bet that is your problem.
If it is, I would get a good high flow unit.
Bill C
I had the SAME EXACT problem. The car idles great and had good part throttle but choked around 4000RPM. I trouble shot everything for weeks! I could recite you the wire colors on the back of the ECM after days of probing for signals!!!
I was sitting behind the car while it was idling and my son (12 Year old) snapped the throttle open to hear the eng rev. :rolleyes:
I noticed that the exhaust sounded normal until the rpm came up and then it sounded like it was being chocked off.
LONG STORY SHORT! :D The CAT was just about plugged solid. I changed the CAT and she ran like a scalded Cat!!!!!
I would just unbolt the cat and see if that changes the way she runs. :thumbs: I bet that is your problem.
If it is, I would get a good high flow unit.
Bill C
YOU WERE RIGHT!
i cut off the cat and mufflers and se is running like a burning monkey! or a scalded cat ! (whatever you prefer :thumbs:)
and she sounds MEAN with an open y-pipe :yesnod:
now i need to figure out why it got clogged .... :smash:
Thank you everyone for helping me!
:cheers:
Daniel
Race Director
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Posts: 12,832
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From: Canton GA
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St. Jude Donor '03-'05-'06-'10-'11-'12
Re: Cannot rev. past 4500 part 2... (Daniel DK)
now i need to figure out why it got clogged ....
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Cannot rev. past 4500 part 2... (Daniel DK)
Dan
I agree with the too rich theory! :iagree: and had the same problem which may have contributed to my cat clogging up. I believe mine was more due to age/miles. She had 145K on the origional converter when it plugged up.
I had my injectors rebuilt and I installed a Accell Super coil. I also installed new plugs, wires, and a cap and rotor.
The coil seemed to make a big difference. The plugs burned much cleaner and when I went through emmisions the guy running the machine couldn't believe that the car had 145K on the odometer! Emissions were GREAT!!
Another contribuitor to the CAT clogging up was that the car had worn valve guide seals and did the start up oil cloud.
I recommend fixing all of those things and you should have many many miles of trouble free driving.
Bill Curlee
[Modified by Bill Curlee, 11:01 PM 7/13/2003]
I agree with the too rich theory! :iagree: and had the same problem which may have contributed to my cat clogging up. I believe mine was more due to age/miles. She had 145K on the origional converter when it plugged up.
I had my injectors rebuilt and I installed a Accell Super coil. I also installed new plugs, wires, and a cap and rotor.
The coil seemed to make a big difference. The plugs burned much cleaner and when I went through emmisions the guy running the machine couldn't believe that the car had 145K on the odometer! Emissions were GREAT!!
Another contribuitor to the CAT clogging up was that the car had worn valve guide seals and did the start up oil cloud.
I recommend fixing all of those things and you should have many many miles of trouble free driving.
Bill Curlee
[Modified by Bill Curlee, 11:01 PM 7/13/2003]
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Cannot rev. past 4500 part 2... (Bill Curlee)
I took mine for a quicky ride on I-95 after I removed the CAT and it felt like I was in a Winston Cup car! Whooooooooooooooo whooooooooooooo it sounded BAD!!!!!!!!!! :D :D :D I meen COOL :cool: :cool:
With the exhaust dumping out right below your butt,, every thing inside the car was vibrating. I got lots of peoples attention!!! :yesnod:
Get a high flow cat if your going to stick one back on. That way if you modify it later ( headers heads manifold and high flow runners) the CAT wont be too much of an obstruction!
BC
With the exhaust dumping out right below your butt,, every thing inside the car was vibrating. I got lots of peoples attention!!! :yesnod:
Get a high flow cat if your going to stick one back on. That way if you modify it later ( headers heads manifold and high flow runners) the CAT wont be too much of an obstruction!
BC
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 1,135
Likes: 17
Re: Cannot rev. past 4500 part 2... (Bill Curlee)
I took mine for a quicky ride on I-95 after I removed the CAT and it felt like I was in a Winston Cup car! Whooooooooooooooo whooooooooooooo it sounded BAD!!!!!!!!!! :D :D :D I meen COOL :cool: :cool:
With the exhaust dumping out right below your butt,, every thing inside the car was vibrating. I got lots of peoples attention!!! :yesnod:
Get a high flow cat if your going to stick one back on. That way if you modify it later ( headers heads manifold and high flow runners) the CAT wont be too much of an obstruction!
BC
With the exhaust dumping out right below your butt,, every thing inside the car was vibrating. I got lots of peoples attention!!! :yesnod:
Get a high flow cat if your going to stick one back on. That way if you modify it later ( headers heads manifold and high flow runners) the CAT wont be too much of an obstruction!
BC
Sounds MEAN! :smash:
:cheers:
Daniel
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Cannot rev. past 4500 part 2... (Daniel DK)
Dan
The best cut out that I have seen so far is one from QUICKTIME.
Go no the internet (I use GOOGLE) and type in quicktime. Their web site is very good and they have LOTS of wave files! :yesnod:
BC
The best cut out that I have seen so far is one from QUICKTIME.
Go no the internet (I use GOOGLE) and type in quicktime. Their web site is very good and they have LOTS of wave files! :yesnod:
BC