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Old 04-10-2012, 12:46 PM
Gkeepa Gkeepa is offline
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Default Injector questions.

I was thinking of buying some refurbished injectors off Ebay, but then I read this:


"stock injectors are 24 lb hr. While there are multiple brands making 24 lb injectors they are NOT the same and anything other than stock ACDelco ones will require a PCM tune to adjust for them."

Will the car still run without a tune after non Delco injectors are installed?
Trying to minimize complexity/steps/vehicle downtime...thanks in advance for any insight.


BTW, this is part of the Ebay auction/ad:


24 LB Fuel Injectors Camaro Mustang Corvette LT1 24lb

Item Description

This is a set of 24 lb fuel injectors. These injectors have been ultrasonically cleaned. They have been flow and induction tested with ASNU fuel injector servicing equipment. These have new O rings and filter baskets installed.
These are flow matched from a large batch of fuel injectors and flow with less than 1% variance
These will fit the LT1, TPI engines, and 5.0 mustangs along with many others.
These injectors are flow matched from many sets of injectors to give you top performance. Flow sheet will be included
The injectors will come shipped sealed so they stay in like new condition until you are ready to install them.
We will gaurantee these to be free from defects for 3 years.
We are an ASNU certified service center and we stand behind what we sell.
Fast Payment will get you fast shipping.
Item must ship to the shipping address on your paypal payment. Please do not contact me after the payment and ask me to ship it to a different address, this is against paypals protection policy. Please change the shipping address when you are making the payment if you need it to go to a different address.
You should receive an email from to your paypal email address when you item ships USPS. They will provide you with a confirmation number. Keep in mind this number is not a tracking number, it just confirms delivery. I ship items as soon as possible. If your item is shipping with Fedex I will contact you with a tracking number. Please let me know if you have any questions about your shipment.










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Sell one like this
24 LB Fuel Injectors Camaro Mustang Corvette LT1 24lb Impala Caprice injecter

Ultrasonically Cleaned and Flow Matched



Seller: Member id jscottwrxsti2004 ( Feedback Score Of 3265)
99.8% Positive feedback
Save this seller | See other items from this seller | Visit store: jscottwrxsti2004






Item condition:RemanufacturedCompatibility: This information is not available.Time left:15d 23h (Apr 26, 201210:36:56 PDT)Quantity:
4 available / 4 sold
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  #2  
Old 04-10-2012, 02:36 PM
Marky Dissod Marky Dissod is offline
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Quote:
Originally Posted by Gkeepa View Post
I was thinking of buying some refurbished injectors off Ebay, but then I read this:

"stock injectors are 24 lb hr. While there are multiple brands making 24 lb injectors they are NOT the same and anything other than stock ACDelco ones will require a PCM tune to adjust for them."

Will the car still run without a tune after non Delco injectors are installed?
Trying to minimize complexity/steps/vehicle downtime thanks in advance for any insight.
1st of all, not all 24lb/hr injectors are actually rated equal.
The complete rating for LT1 injectors:
24 lb/hr @ 43.5 PSI (many forget the PSI rating)
If you do not have BOTH the lb/hr AND the PSI [at the fuel pump], you have an incomplete rating, thus you can't be sure if they actually flow the same or not.

2nd, even with two [sets of] injectors rated, say, 24 lb/hr @ 43.5PSI, they still must have the same OFFSET (response timing).
If the offsets differ, the injector[s] will open &/or close faster/slower than expected/intended.

In other words:
if both the flow and the fuel pump pressure ratings are not EXACTLY the same, the tune will need to be adjusted to compensate.
if the injector offset is not EXACTLY the same, the tune will need to be adjusted to compensate.

A closed loop tune may be able to compensate for injectors that are flow-rated within 5% of the original spec, but that's asking a lot.
Doubt that any closed loop tune would be able to compensate for injectors with varying offsets.

Can't answer your last question. Describe your car in your sig ONCE, and you'll never need describe it again. (I'll venture a guess that 96 MIGHT handle it better than 94/95, but I'll never try it; can you guess why?)

Consider the following alternatives if you want zero complexity:
http://www.corvetteinjectors.com/sho...?productid=257
http://fuelinjectorconnection.com/sh...d&productId=50
http://fuelinjectorman.com
http://hurstinjectorservice.com
http://www.cruzinperformance.com/fuelinj.html
http://injector-rehab.com/shop/Dynamic-Cleaning.html
http://www.witchhunter.com/injectorserv1.php4
(I still haven't decided which I'll use )
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Old 04-10-2012, 03:04 PM
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Ask the seller if they are rated at 43.5 psi. Ford rates their injectors at 39.2 PSI, and the seller threw "Mustang" in the title.

The flow rate difference due to the difference in the pressures used by GM and Ford for the flow rating is 5.4%. The PCM can pull out up to 15% fuel using the long term fuel corrections.

Why do you feel you need refurbished injectors ?
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Old 04-10-2012, 08:27 PM
Gkeepa Gkeepa is offline
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Marky/Jason-

Thanks for the good info. I will definitely get my car info.(1994 Caprice Wagon)in my signature...that is understandable how that could be a big help to someone trying to answer a question.

I wanted to get new injectors b/c I think one or more may be clogged/partially clogged. I'll cut to the chase: ran the car outta gas one night, and I don't know if that correlates, but it seemed to develop a misfire/sputter subsequently whenever I would give it partial throttle/lightly accelerate. An example: I'd drive onto an on-ramp with the car in cruise ctrl. and the knock/misfire/stumble would show upas it tried to keep the set speed up. I could get it to do it while coasting in neutral and mashing on the throttle. Apply the brake w/tranny in "D" while depressing gas pedal and get it to do it. Sometimes it's worse than others. I have changed the plugs and wires, fuel pressure regulator, fuel filter(all ACDelco stuff)...even the front shocks. Still getting the stumble. My mobile mech buddy. subs a bay at HIS bud's brick and mortar auto repair facility. He put it on the scanner. Fuel pressure is around 42-ish, but there is an "electrical anomaly"...I figure it's either the cap and rotor or injectors cruddied up b/c I ran it out of gas. Thought I would swap in some injectors that I knew were cleaned and ready to go b4 I mess with the cap and rotor. The way I see it is these are pretty much all maintenance items for a car of this age and Unknown(by me, anyways)maintenance history. Injectors would be easier to do(IF that is in fact my issue), than the cap and rotor(which I will probably do later, anyways, unless I have to do it sooner).

So that's where I stand at this point. I got a lot of great ideas from reading the various posts on this site regarding LT1 misfire issues. Just trying to rule out possible reasons as to this issue I'm having. it's been frustrating, but I know we'll get there eventually...keep buying parts, and see what develops, I reckon. I'm no mechanic, but it seems it might be a fuel delivery problemb/c of the throttle response component. I don't know.

Thanks again, Guys.
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Old 04-10-2012, 09:02 PM
sherlock9c1 sherlock9c1 is offline
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There is no way the injectors got crudded up because you ran out of gas.

1. There is a filter on the inlet side of the fuel pump.
2. There is an in-line filter downstream of the fuel pump.
3. The inside of your gas tank is a lot cleaner inside than you might think. I once cleaned out a B-body gas tank with 166,000 miles on it and there was hardly any dirt in there at all.

What is the fuel pressure when the car stumbles?
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Old 04-10-2012, 10:45 PM
Gkeepa Gkeepa is offline
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Quote:
Originally Posted by sherlock9c1 View Post
There is no way the injectors got crudded up because you ran out of gas.

1. There is a filter on the inlet side of the fuel pump.
2. There is an in-line filter downstream of the fuel pump.
3. The inside of your gas tank is a lot cleaner inside than you might think. I once cleaned out a B-body gas tank with 166,000 miles on it and there was hardly any dirt in there at all.

What is the fuel pressure when the car stumbles?

I have not checked that...which way would you suggest is the best to accomplish that? Also, should I not be driving the car until this is fixed? Thanks.
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Last edited by Gkeepa; 04-10-2012 at 11:01 PM. Reason: b/c I'm a clueless newbie
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Old 04-11-2012, 08:28 AM
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I had similar issues a couple years back. I replaced all the injectors but it didn't solve the problem. Turned out to be just a short in one of the little injector wires.

Get a screwdriver, put one end on an injector and the other end up to your ear...you should be able to clearly her the injector pulsing. Then wiggle the injector wire and listen for any change.

Easily found which injector had the bad wire and could have saved myself a lot of money on injectors had I thought to check the wires first.
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Old 04-11-2012, 03:09 PM
Gkeepa Gkeepa is offline
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Quote:
Originally Posted by Gacob View Post
I had similar issues a couple years back. I replaced all the injectors but it didn't solve the problem. Turned out to be just a short in one of the little injector wires.

Get a screwdriver, put one end on an injector and the other end up to your ear...you should be able to clearly her the injector pulsing. Then wiggle the injector wire and listen for any change.

Easily found which injector had the bad wire and could have saved myself a lot of money on injectors had I thought to check the wires first.
Alright, that will be the 1st thing I do, I gonna go buy a fuel press gauge at HF later just in case the wires are all good, and hook that up to get a reading during acceleration. Thanks for all the pointers.
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Old 04-11-2012, 10:33 PM
Gkeepa Gkeepa is offline
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Well, all the injectors seem to be pulsing just fine...no change when wiggling wires. Check fuel pressure while vehicle is operating next.
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