Injectors-Buyer Beware
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Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Thread Starter
Team Owner
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Posts: 35,065
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Anyway, how's this. Manufacturer's starting point spec...is that better
You just don't get it.
RACE ON!!!
RACE ON!!!
Safety Car
Joined: Dec 1999
Posts: 4,691
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From: Framingham MA
Ultimately different injectors typically wil notl flow in linear fashion. For instance your 40# injector may not flow 67% more fuel 1.3 ms pulse (idle) like a factory 24# at 1.3ms. At 100% duty cycle it should flow 67% (assuming they are rated at the same fuel pressure)
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
To make it easy you could always turn your base fuel pressure down to compensate and make the 40# injectors look like 37# If you base FP is 43.5, to make it look like 37# it would need to turn down about psi. (37/40)^2 * 43.5
Ultimately different injectors typically wil notl flow in linear fashion. For instance your 40# injector may not flow 67% more fuel 1.3 ms pulse (idle) like a factory 24# at 1.3ms. At 100% duty cycle it should flow 67% (assuming they are rated at the same fuel pressure)
Ultimately different injectors typically wil notl flow in linear fashion. For instance your 40# injector may not flow 67% more fuel 1.3 ms pulse (idle) like a factory 24# at 1.3ms. At 100% duty cycle it should flow 67% (assuming they are rated at the same fuel pressure)
I think I'm just more pissed that I purchased a 37, told it was really a 38.3, and really flowed 40.
It costs time, money, and aggravation.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Originally Posted by jsup
Are you a retired English teacher?
Anyway, how's this. Manufacturer's starting point spec...is that better
Anyway, how's this. Manufacturer's starting point spec...is that better
Originally Posted by jsup
I understand where you're going, but it's irrelevent until I fix what I know I can get right. THEN I can start looking at the plugs.
RACE ON!!!
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Anyway, I'll concede, I don't have a clue. How about you provide some clues and we'll play puzzle and I'll try to figure it out.
Pro
Joined: Mar 2007
Posts: 526
Likes: 1
From: San Angelo Texas
Well this will be locked soon. It's kind of hard to pick out the info with all the bashing. Why can't people just agree to disagree?
You two are both smart and I read a ton of your posts so please calm it down a little before you guys get banned or something.
You two are both smart and I read a ton of your posts so please calm it down a little before you guys get banned or something.
Drifting
Joined: Oct 2006
Posts: 1,934
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From: Citrus Heights California
Jsup:
I got burnt twice with bad injectors. The first time they were rebuilts. The second time it was new yellow top Accels.
Nothing will make me more irate than to spend time, money and effort only to have the car run like crap.
I'm on my third set of injectors now and all is well. I just hope that the injectors last.
I'm usually the one ranting and raving about being burnt by dealers that sell you bad or the wrong injectors. So I know what you're going through.
You'll get things squared away soon.
We really need to be careful and choose the right injector regardless of the price. I tried to save money and it cost me.
I want to drive my Vette not rip it apart.
I got burnt twice with bad injectors. The first time they were rebuilts. The second time it was new yellow top Accels.
Nothing will make me more irate than to spend time, money and effort only to have the car run like crap.
I'm on my third set of injectors now and all is well. I just hope that the injectors last.
I'm usually the one ranting and raving about being burnt by dealers that sell you bad or the wrong injectors. So I know what you're going through.
You'll get things squared away soon.
We really need to be careful and choose the right injector regardless of the price. I tried to save money and it cost me.
I want to drive my Vette not rip it apart.
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Le Mans Master
Joined: Dec 2004
Posts: 5,789
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From: Myrtle Beach SC
St. Jude Donor '05-'06
As mentioned the plugs may be out of spec causing (or helping) the carbon but just as you need to datalog after a tune it takes time for the PCM to tweak itself so the tuner can do his job.
Overall the pattern and flow rate are not as important as the duty cycle and that is what The tuner adjust for based on your setup as that determines the most efficient flow.
Last edited by Redeasysport; Apr 26, 2008 at 10:11 AM.
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
I could be wrong but as mentioned you may have not let the car run long enough. The ECM/PCM will adjust the duty cycle based on the O2's over a short period of time. A tune just gets you in the ballpark so to speak. Once again I could be wrong but I believe it would have the ability to compensate easily for that 3lb difference. The only caveat here is when the injectors are so oversized that the duty cycle drops so low as to make the flow unreliable. I can't remember the exact # but the duty cycle at WOT should be under 90% and that is what is important. I would be much more upset if the injector under flowed leading to the engine going lean at WOT.
As mentioned the plugs may be out of spec causing (or helping) the carbon but just as you need to datalog after a tune it takes time for the PCM to tweak itself so the tuner can do his job.
As mentioned the plugs may be out of spec causing (or helping) the carbon but just as you need to datalog after a tune it takes time for the PCM to tweak itself so the tuner can do his job.
Too many moving parts.
Could the plugs be too cold? Sure. Could the combination of cold plugs and a bad tune produce this result? Sure. However, when you start with a bullshlt rating these other variables are impossible to nail down.
It's like X+Y=4. What's the value of X? That's my point. Unless I can get a solid baseline from known specs, which I would expect from a manufacturer, how am I supposed to adjust the other variables effectively?
It's a function of time, money, and aggravation becuase specs ain't really specs and as the consumer I don't see why it's my responsibility to figure it out. I should get what I pay for.
Le Mans Master
Joined: Dec 2004
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From: Myrtle Beach SC
St. Jude Donor '05-'06
I am still not sure what you expect. Injectors are not made in a lab and can and will vary some. Maybe 10% is a little extreme. Mabey the supplier needs to rethink what he tells his customers. Tuning a PCM is far from an exact science too. All in all I think you may be making too big a deal about it. As long as they all flow the same it will probably take the same amount of dataloging/dyno time to get it tuned. There are so many variable inside the engine itself. As I said I would want an injector that flows more than advertised than less any day of the week as long as it is not excessively so. The PCM can compensate for richness but the engine will blow/overheat/ run bad on lean.
Drifting
Joined: Sep 2004
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You bought 40 lbers. you're right the manufacturer/vendor was "wrong". the photos of the plugs show it was running rich. to bad you did not have a set of 37's around - i suspect if you ran them with new plugs - they would look the same!
did the vendor return your money after you returned the injectors?
Carl Johansson
did the vendor return your money after you returned the injectors?
Carl Johansson
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
You bought 40 lbers. you're right the manufacturer/vendor was "wrong". the photos of the plugs show it was running rich. to bad you did not have a set of 37's around - i suspect if you ran them with new plugs - they would look the same!
did the vendor return your money after you returned the injectors?
Carl Johansson
did the vendor return your money after you returned the injectors?
Carl Johansson
I have another vendor who took back those 40lb injectors and traded me straight up for 25s. I am seriously considering going with 30s or 32s. I have a couple days to decide. I really believe 30s would be dead on ***** for my application.
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
I am still not sure what you expect. Injectors are not made in a lab and can and will vary some. Maybe 10% is a little extreme. Mabey the supplier needs to rethink what he tells his customers. Tuning a PCM is far from an exact science too. All in all I think you may be making too big a deal about it. As long as they all flow the same it will probably take the same amount of dataloging/dyno time to get it tuned. There are so many variable inside the engine itself. As I said I would want an injector that flows more than advertised than less any day of the week as long as it is not excessively so. The PCM can compensate for richness but the engine will blow/overheat/ run bad on lean.
The vendor told me they were either 38.3 or 37. Which they are not.
I know what you are saying about none of this being an exact science, however, having parts that don't perform as advertised don't make it easier.
Le Mans Master
Joined: Jun 2006
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From: One day you're a Comet...the next day you're dust... Arkansas
Nope. I have no more contact with that vendor. They have no phone number listed, it's an email only business.
I have another vendor who took back those 40lb injectors and traded me straight up for 25s. I am seriously considering going with 30s or 32s. I have a couple days to decide. I really believe 30s would be dead on ***** for my application.
I have another vendor who took back those 40lb injectors and traded me straight up for 25s. I am seriously considering going with 30s or 32s. I have a couple days to decide. I really believe 30s would be dead on ***** for my application.
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
I finally ordered a new set of 32s. I'm not jerking around any more. They are brand new and flow matched. they are 30lb bosh rated 32 at three bar.
I agree with you. That's where I need to be.
I got them from FICINJECTORS. Jon has been very good to me and I have no problem giving them my money. Hell, he called my house TODAY on a Saturday when he got my email. How many people do that?
I agree with you. That's where I need to be.
I got them from FICINJECTORS. Jon has been very good to me and I have no problem giving them my money. Hell, he called my house TODAY on a Saturday when he got my email. How many people do that?
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Safety Car
Joined: May 2002
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From: Somewhere nowhere
[QUOTE=Kool88vette;1565189580]Jsup:
I got burnt twice with bad injectors. The first time they were rebuilts. The second time it was new yellow top Accels.
QUOTE]
may I ask....
what happened with the new accel;s?
The new accels are suppose to be OK.
I got burnt twice with bad injectors. The first time they were rebuilts. The second time it was new yellow top Accels.
QUOTE]
may I ask....
what happened with the new accel;s?
The new accels are suppose to be OK.
