Different Truck Injector Sizes by Year?
07-11-2014, 07:17 PM
#1
On The Tree
Thread Starter
Different Truck Injector Sizes by Year? Hey Everyone,
I'm in the parts gathering phase for an LSx swap on my '89 Blazer. My donor engine is a 5.3L (LM7) from a 2000 Yukon that had around 146k miles on it when it was wrecked and I got the whole vehicle on the cheap. I plan on freshening it up a little bit before I do the swap and was trying to figure out what injectors I should get. I had heard on a few different websites that the 99-00 engines had smaller injectors than later models but haven't been able to find anything that spells out what the differences are. I had also read that the flex fuel and 8.1L big block injectors are better than the gas only models but other people say there's no significant difference until you go with an aftermarket source. I'll most likely be trying to find reman. or lightly used injectors for replacements due to a tight budget so I guess my question is should I be looking at another year to source my injectors from? Also are all truck injectors interchangeable (4.8, 5.3, 6.0, 8.1) or do I need to stick with the original size? I found a local guy on Craigslist that has a complete "like new" intake (w/injectors, rails, etc.) from an '02 Tahoe that he removed for a supercharger swap at 23k miles and I'm thinking about picking up if it's what I'm looking for. Thanks for any info or advice you guys can give.
-Anthony
I'm in the parts gathering phase for an LSx swap on my '89 Blazer. My donor engine is a 5.3L (LM7) from a 2000 Yukon that had around 146k miles on it when it was wrecked and I got the whole vehicle on the cheap. I plan on freshening it up a little bit before I do the swap and was trying to figure out what injectors I should get. I had heard on a few different websites that the 99-00 engines had smaller injectors than later models but haven't been able to find anything that spells out what the differences are. I had also read that the flex fuel and 8.1L big block injectors are better than the gas only models but other people say there's no significant difference until you go with an aftermarket source. I'll most likely be trying to find reman. or lightly used injectors for replacements due to a tight budget so I guess my question is should I be looking at another year to source my injectors from? Also are all truck injectors interchangeable (4.8, 5.3, 6.0, 8.1) or do I need to stick with the original size? I found a local guy on Craigslist that has a complete "like new" intake (w/injectors, rails, etc.) from an '02 Tahoe that he removed for a supercharger swap at 23k miles and I'm thinking about picking up if it's what I'm looking for. Thanks for any info or advice you guys can give.
-Anthony
07-11-2014, 08:46 PM
#2
Depends on how much he wants for the setup? I suggest you just clean those up and put new o-rings if necessary unless you know there was something wrong with them. I almost pulled the trigger in another LM7 setup to have more for mine but then found the TBSS intake for $111 new shipped. The intake is almost worth nothing so having two..
07-11-2014, 09:08 PM
#3
On The Tree
Thread Starter
Depends on how much he wants for the setup? I suggest you just clean those up and put new o-rings if necessary unless you know there was something wrong with them. I almost pulled the trigger in another LM7 setup to have more for mine but then found the TBSS intake for $111 new shipped. The intake is almost worth nothing so having two..
Do you know if there is a size difference between the '00 and '02 5.3L injectors.
07-11-2014, 09:43 PM
#4
That's not bad if you would be happy with that size injector for a good while. I did some research when I was looking for bigger injectors for mine and did not conclude that there was any size increase as far as 2002. Best bet is to ask what the part # is on the injector and just google "<part number> lbs/hr." You should find your answer pretty quick and that's the safest way to know. You could do the same for yours.
Personally I would trust higher-mileage injectors that had been running recently over injectors that were sat on the shelf as an intake unit 11 years ago..there's 11 yr old fuel gunk sitting in there and that could net you a set of low mile but clogged injectors. If they had been pulled and cleaned and/or stored in a specific way maybe that's different but I would be cautious. You may be surprised by an inexpensive alternative by searching Rockauto or similar to get a part number for the piece(s) you are missing and then searching frugalmechanic or Amazon.com for the replacement parts. Would also save you from removing and reinstalling all of that to have basically the same parts. That's how I've found the later model intake and other bits that I am upgrading my LM7 with now.
FWIW, the "flex" injectors in theory have to have a higher potential rating because ethanol os less power-dense than gasoline. The computers in the flex vehicles detect the fuel by a couple of different methods and adjust fueling appropriately. If you find flex injectors and put them on a non-flex vehicle, they would probably run the higher rate and very rich unless you got a custom tune for it.
Personally I would trust higher-mileage injectors that had been running recently over injectors that were sat on the shelf as an intake unit 11 years ago..there's 11 yr old fuel gunk sitting in there and that could net you a set of low mile but clogged injectors. If they had been pulled and cleaned and/or stored in a specific way maybe that's different but I would be cautious. You may be surprised by an inexpensive alternative by searching Rockauto or similar to get a part number for the piece(s) you are missing and then searching frugalmechanic or Amazon.com for the replacement parts. Would also save you from removing and reinstalling all of that to have basically the same parts. That's how I've found the later model intake and other bits that I am upgrading my LM7 with now.
FWIW, the "flex" injectors in theory have to have a higher potential rating because ethanol os less power-dense than gasoline. The computers in the flex vehicles detect the fuel by a couple of different methods and adjust fueling appropriately. If you find flex injectors and put them on a non-flex vehicle, they would probably run the higher rate and very rich unless you got a custom tune for it.
07-11-2014, 11:55 PM
#5
yeah the FF injectors have flow numbers given at like 50 psi
the FPR is FF specific and regulates it to around there
you'd have to do some injector math/scaling and adjust it in the tune if you wanna run em at "normal" psi
there are online calculators on the ol google
the FPR is FF specific and regulates it to around there
you'd have to do some injector math/scaling and adjust it in the tune if you wanna run em at "normal" psi
there are online calculators on the ol google
07-12-2014, 01:31 AM
#6
*Injector Values listed below are based off factory tune data* I don't have part number to cross reference.
Some of the 99s did use a lower rating. 21.763701
2000 and up would shows a 24.801938 with a return style fuel system based on the 48-52 PSI at idle under vacuum with an adjustable vacuum operated fuel pressure regulator.
2002 L59 Flex fuel injectors are 33.048583 based on a return style fuel system with the 48-52 Base PSI at idle under vacuum with an adjustable vacuum operated fuel pressure regulator.
2004 and up returnless style Start at 24.491914 and ramp up to 27.096118 Based on Manifold vacuum. They also run a constant fuel pressure of 60 PSI
05- 07 classic Flex fuel injectors start at 35.404767 and ramp up to 38.443005 on a returnless system also based off a constant fuel pressure of 60 PSI.
8.1 injectors are 29.948341 on a return style but I don't know what base PSI they run at
So most everything was the same with the exception of flex fuel injectors or 8.1L injectors.
Flex fuel injectors have a different plug from the standard truck injector.
You're PCM needs to have the correct data for which ever injectors you are running or it won't run correctly.
If you're doing a swap, there is no way for them to know exactly which year the engine is from. They get the info based on what you tell them and what comes up when they read the PCM Data.
If it were me, I would do away with all the nonsense and go with a 2002 truck set up with No EGR and No Air injection.
The Air injection only runs at startup for a predetermined amount of time (210 seconds) to inject fresh air into the exhaust stream to lean out the mixture and light off the catalyst faster.
The EGR hardly ever runs as it has a small window based on MPH and TPS reading that it will operate in. You basically have to be lightly cruising at a certain speed or RPM with little to no throttle input for it to work. This is putting hot exhaust gasses back into the intake tract. If the engine runs efficiently and the catalyst system is still intact and functioning correctly, there is no need for this type of system. GM did away with it and has not used it sense.
Some of the 99s did use a lower rating. 21.763701
2000 and up would shows a 24.801938 with a return style fuel system based on the 48-52 PSI at idle under vacuum with an adjustable vacuum operated fuel pressure regulator.
2002 L59 Flex fuel injectors are 33.048583 based on a return style fuel system with the 48-52 Base PSI at idle under vacuum with an adjustable vacuum operated fuel pressure regulator.
2004 and up returnless style Start at 24.491914 and ramp up to 27.096118 Based on Manifold vacuum. They also run a constant fuel pressure of 60 PSI
05- 07 classic Flex fuel injectors start at 35.404767 and ramp up to 38.443005 on a returnless system also based off a constant fuel pressure of 60 PSI.
8.1 injectors are 29.948341 on a return style but I don't know what base PSI they run at
So most everything was the same with the exception of flex fuel injectors or 8.1L injectors.
Flex fuel injectors have a different plug from the standard truck injector.
You're PCM needs to have the correct data for which ever injectors you are running or it won't run correctly.
If you're doing a swap, there is no way for them to know exactly which year the engine is from. They get the info based on what you tell them and what comes up when they read the PCM Data.
If it were me, I would do away with all the nonsense and go with a 2002 truck set up with No EGR and No Air injection.
The Air injection only runs at startup for a predetermined amount of time (210 seconds) to inject fresh air into the exhaust stream to lean out the mixture and light off the catalyst faster.
The EGR hardly ever runs as it has a small window based on MPH and TPS reading that it will operate in. You basically have to be lightly cruising at a certain speed or RPM with little to no throttle input for it to work. This is putting hot exhaust gasses back into the intake tract. If the engine runs efficiently and the catalyst system is still intact and functioning correctly, there is no need for this type of system. GM did away with it and has not used it sense.
07-12-2014, 07:48 AM
#7
Fuel injector questions aren't pistons, rods or crankshafts and don't belong here in the internal engine section.
The https://ls1tech.com/forums/fueling-injection-8/ section is where this belongs.
The https://ls1tech.com/forums/fueling-injection-8/ section is where this belongs.
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07-12-2014, 10:33 AM
#8
on the old low mileage injectors I would echo the other poster's concerns. A friend recently put an engine in his car that hadn't run in probably about 6 years, would not start, did all the diagnostics had fuel pressure, had spark. Little ether and it fired instantly. Swapped for a rail and injectors that had last run back in December and it ran perfectly.
After seeing that I think I will always thoroughly drain a rail rather than leave it sit full of fuel on the engine. If it is dry there is nothing to varnish up.
After seeing that I think I will always thoroughly drain a rail rather than leave it sit full of fuel on the engine. If it is dry there is nothing to varnish up.
07-15-2014, 12:34 AM
#9
On The Tree
Thread Starter
Thanks for all of the replies everyone. This was all good helpful info.
1FastBrick - That was exactly what I was looking for thank you.
I'll be getting this thing tuned whether I stick with what's in there now or if I get something else since I will need to have VATS removed and a few other things tweaked for the swap. I'm hoping to get a couple of other bolt-ons added before I get the 5.3 dropped in so a re-tune is definitely in the plans to make everything work together.
As far as getting this thing smogged after the swap goes, I think the easiest way to get everything taken care of will be to get a PCM from an '02 truck like 1FastBrick suggested. From what I've been reading that should be the first year without EGR and AIR but will still be DBC and have the red/blue connectors like my '00 donor so I won't have to buy another harness or re-pin the existing one. Then when it comes time to do the smog ref inspection/certification, I won't have to worry about a lot of the smog headaches when they hook up to the PCM to check the VIN and see what smog items should be there.
Thanks again for all the info and tips everyone
1FastBrick - That was exactly what I was looking for thank you.
I'll be getting this thing tuned whether I stick with what's in there now or if I get something else since I will need to have VATS removed and a few other things tweaked for the swap. I'm hoping to get a couple of other bolt-ons added before I get the 5.3 dropped in so a re-tune is definitely in the plans to make everything work together.
As far as getting this thing smogged after the swap goes, I think the easiest way to get everything taken care of will be to get a PCM from an '02 truck like 1FastBrick suggested. From what I've been reading that should be the first year without EGR and AIR but will still be DBC and have the red/blue connectors like my '00 donor so I won't have to buy another harness or re-pin the existing one. Then when it comes time to do the smog ref inspection/certification, I won't have to worry about a lot of the smog headaches when they hook up to the PCM to check the VIN and see what smog items should be there.
Thanks again for all the info and tips everyone
07-15-2014, 12:38 AM
#10
On The Tree
Thread Starter
Paul Bell - Sorry about that. I clicked on the first Gen III section I saw and didn't realize there were different sections for internal, external, fuel delivery, etc. Can you move this to the appropriate forum?
07-15-2014, 12:54 AM
#11
On The Tree
Thread Starter
In case anyone else is interested in another source, I found this on LT1Swap (http://www.lt1swap.com/inj_maf.htm)
FUEL INJECTOR FLOW RATES - GM used various different sized fuel injectors across engine sizes and vehicle platforms. I have compiled this data from looking at many different calibrations. GM also changed the style of fuel rail from a type with vacuum referenced regulator, supply and return lines, to a return-less system without a regulator in 2004 for all Pickups, SUV's and so on. The ONLY exception, is Flex Fuel 5.3L (L59 Vin Z) kept the return style rail for model year 2004, and in 2005 went return-less.
25317669, 25320287 - 1999, 4.8L and 5.3L - flows 2.742 gm/sec or 21.8 lb/hr @ 58 psi
25317670, 25320288, 25323974 - 1999-2000 6.0L, 2000 4.8L and 5.3L - flows 3.125 gm/sec or 24.8lb/hr @ 58 psi
25317628 2001-2007 - 4.8L, 5.3L, 6.0L - flows 3.180 gm/sec or 25.2lb/hr @ 58 psi
25326903 - 5.3L L59 Vin Z, flex fuel 5.3L - flows 4.164 gm/sec or 33lb/hr @ 50 psi
12554271 - 1997-1998 5.7L LS1 - flows 3.727 gm/sec or 29.6lb/hr @ 58 psi
12555894 - 1999-2000 5.7L LS1 - flows 3.438 gm/sec or 27.3lb/hr @ 58 psi
12561462 - 2001-2004 5.7L LS1, LS6 - flows 3.781 gm/sec or 30lb/hr @ 58 psi
PCM SERVICE NO. USAGE - This will list the service number printed on the PCM that I have come across. This should pretty well complete any PCM you'll see 1999 to 2007 for Pickup trucks. Some PCM's will work with cable thorttle, these will have a ( ** ) next to the 8 digit number. These PCM's that work with cable thorttle were for sure in Express Vans 2003 to 2007, V6 4.3L Pickups, and in 2004, GTO's with the 5.7L LS1.
09354896 - Used 1999-2000 in Vortec Trucks, Blue & Red Connectors, F-Body, Y-Body
12200411 - Used 2001-2002 in Vortec Trucks, Blue & Red Connectors, F-Body, (to 2004 in Y-Body - so I've read)
All 2003-2007 PCMs have Blue & Green Connectors. (** WILL WORK WITH CABLE THORTTLE)
12576106**, 12581565**, 12582605 - 2003 Vortec Truck
12586242, 12586243** - 2004 Vortec Truck
12589462**, 12589463 - 2005 Vortec Truck
12602801, 12602802** - 2006-2007 Classic Vortec Truck
It looks like '99 was the year with the smallest/least flowing truck injectors. the '00 year was pretty close to the '01-'07 injectors which should be fine for what I have planned.
FUEL INJECTOR FLOW RATES - GM used various different sized fuel injectors across engine sizes and vehicle platforms. I have compiled this data from looking at many different calibrations. GM also changed the style of fuel rail from a type with vacuum referenced regulator, supply and return lines, to a return-less system without a regulator in 2004 for all Pickups, SUV's and so on. The ONLY exception, is Flex Fuel 5.3L (L59 Vin Z) kept the return style rail for model year 2004, and in 2005 went return-less.
25317669, 25320287 - 1999, 4.8L and 5.3L - flows 2.742 gm/sec or 21.8 lb/hr @ 58 psi
25317670, 25320288, 25323974 - 1999-2000 6.0L, 2000 4.8L and 5.3L - flows 3.125 gm/sec or 24.8lb/hr @ 58 psi
25317628 2001-2007 - 4.8L, 5.3L, 6.0L - flows 3.180 gm/sec or 25.2lb/hr @ 58 psi
25326903 - 5.3L L59 Vin Z, flex fuel 5.3L - flows 4.164 gm/sec or 33lb/hr @ 50 psi
12554271 - 1997-1998 5.7L LS1 - flows 3.727 gm/sec or 29.6lb/hr @ 58 psi
12555894 - 1999-2000 5.7L LS1 - flows 3.438 gm/sec or 27.3lb/hr @ 58 psi
12561462 - 2001-2004 5.7L LS1, LS6 - flows 3.781 gm/sec or 30lb/hr @ 58 psi
PCM SERVICE NO. USAGE - This will list the service number printed on the PCM that I have come across. This should pretty well complete any PCM you'll see 1999 to 2007 for Pickup trucks. Some PCM's will work with cable thorttle, these will have a ( ** ) next to the 8 digit number. These PCM's that work with cable thorttle were for sure in Express Vans 2003 to 2007, V6 4.3L Pickups, and in 2004, GTO's with the 5.7L LS1.
09354896 - Used 1999-2000 in Vortec Trucks, Blue & Red Connectors, F-Body, Y-Body
12200411 - Used 2001-2002 in Vortec Trucks, Blue & Red Connectors, F-Body, (to 2004 in Y-Body - so I've read)
All 2003-2007 PCMs have Blue & Green Connectors. (** WILL WORK WITH CABLE THORTTLE)
12576106**, 12581565**, 12582605 - 2003 Vortec Truck
12586242, 12586243** - 2004 Vortec Truck
12589462**, 12589463 - 2005 Vortec Truck
12602801, 12602802** - 2006-2007 Classic Vortec Truck
It looks like '99 was the year with the smallest/least flowing truck injectors. the '00 year was pretty close to the '01-'07 injectors which should be fine for what I have planned.
09-15-2014, 06:31 AM
#14
In case anyone else is interested in another source, I found this on LT1Swap (http://www.lt1swap.com/inj_maf.htm)
FUEL INJECTOR FLOW RATES - GM used various different sized fuel injectors across engine sizes and vehicle platforms. I have compiled this data from looking at many different calibrations. GM also changed the style of fuel rail from a type with vacuum referenced regulator, supply and return lines, to a return-less system without a regulator in 2004 for all Pickups, SUV's and so on. The ONLY exception, is Flex Fuel 5.3L (L59 Vin Z) kept the return style rail for model year 2004, and in 2005 went return-less.
25317669, 25320287 - 1999, 4.8L and 5.3L - flows 2.742 gm/sec or 21.8 lb/hr @ 58 psi
25317670, 25320288, 25323974 - 1999-2000 6.0L, 2000 4.8L and 5.3L - flows 3.125 gm/sec or 24.8lb/hr @ 58 psi
25317628 2001-2007 - 4.8L, 5.3L, 6.0L - flows 3.180 gm/sec or 25.2lb/hr @ 58 psi
25326903 - 5.3L L59 Vin Z, flex fuel 5.3L - flows 4.164 gm/sec or 33lb/hr @ 50 psi
12554271 - 1997-1998 5.7L LS1 - flows 3.727 gm/sec or 29.6lb/hr @ 58 psi
12555894 - 1999-2000 5.7L LS1 - flows 3.438 gm/sec or 27.3lb/hr @ 58 psi
12561462 - 2001-2004 5.7L LS1, LS6 - flows 3.781 gm/sec or 30lb/hr @ 58 psi
PCM SERVICE NO. USAGE - This will list the service number printed on the PCM that I have come across. This should pretty well complete any PCM you'll see 1999 to 2007 for Pickup trucks. Some PCM's will work with cable thorttle, these will have a ( ** ) next to the 8 digit number. These PCM's that work with cable thorttle were for sure in Express Vans 2003 to 2007, V6 4.3L Pickups, and in 2004, GTO's with the 5.7L LS1.
09354896 - Used 1999-2000 in Vortec Trucks, Blue & Red Connectors, F-Body, Y-Body
12200411 - Used 2001-2002 in Vortec Trucks, Blue & Red Connectors, F-Body, (to 2004 in Y-Body - so I've read)
All 2003-2007 PCMs have Blue & Green Connectors. (** WILL WORK WITH CABLE THORTTLE)
12576106**, 12581565**, 12582605 - 2003 Vortec Truck
12586242, 12586243** - 2004 Vortec Truck
12589462**, 12589463 - 2005 Vortec Truck
12602801, 12602802** - 2006-2007 Classic Vortec Truck
It looks like '99 was the year with the smallest/least flowing truck injectors. the '00 year was pretty close to the '01-'07 injectors which should be fine for what I have planned.
FUEL INJECTOR FLOW RATES - GM used various different sized fuel injectors across engine sizes and vehicle platforms. I have compiled this data from looking at many different calibrations. GM also changed the style of fuel rail from a type with vacuum referenced regulator, supply and return lines, to a return-less system without a regulator in 2004 for all Pickups, SUV's and so on. The ONLY exception, is Flex Fuel 5.3L (L59 Vin Z) kept the return style rail for model year 2004, and in 2005 went return-less.
25317669, 25320287 - 1999, 4.8L and 5.3L - flows 2.742 gm/sec or 21.8 lb/hr @ 58 psi
25317670, 25320288, 25323974 - 1999-2000 6.0L, 2000 4.8L and 5.3L - flows 3.125 gm/sec or 24.8lb/hr @ 58 psi
25317628 2001-2007 - 4.8L, 5.3L, 6.0L - flows 3.180 gm/sec or 25.2lb/hr @ 58 psi
25326903 - 5.3L L59 Vin Z, flex fuel 5.3L - flows 4.164 gm/sec or 33lb/hr @ 50 psi
12554271 - 1997-1998 5.7L LS1 - flows 3.727 gm/sec or 29.6lb/hr @ 58 psi
12555894 - 1999-2000 5.7L LS1 - flows 3.438 gm/sec or 27.3lb/hr @ 58 psi
12561462 - 2001-2004 5.7L LS1, LS6 - flows 3.781 gm/sec or 30lb/hr @ 58 psi
PCM SERVICE NO. USAGE - This will list the service number printed on the PCM that I have come across. This should pretty well complete any PCM you'll see 1999 to 2007 for Pickup trucks. Some PCM's will work with cable thorttle, these will have a ( ** ) next to the 8 digit number. These PCM's that work with cable thorttle were for sure in Express Vans 2003 to 2007, V6 4.3L Pickups, and in 2004, GTO's with the 5.7L LS1.
09354896 - Used 1999-2000 in Vortec Trucks, Blue & Red Connectors, F-Body, Y-Body
12200411 - Used 2001-2002 in Vortec Trucks, Blue & Red Connectors, F-Body, (to 2004 in Y-Body - so I've read)
All 2003-2007 PCMs have Blue & Green Connectors. (** WILL WORK WITH CABLE THORTTLE)
12576106**, 12581565**, 12582605 - 2003 Vortec Truck
12586242, 12586243** - 2004 Vortec Truck
12589462**, 12589463 - 2005 Vortec Truck
12602801, 12602802** - 2006-2007 Classic Vortec Truck
It looks like '99 was the year with the smallest/least flowing truck injectors. the '00 year was pretty close to the '01-'07 injectors which should be fine for what I have planned.
09-15-2014, 06:53 AM
#15
TECH Addict
I you sure they aren't 12580681? http://r.search.yahoo.com/_ylt=AwrBT...VyE16hpOFQgLE- https://search.yahoo.com/search;_ylt...fr=yfp-t-901-s
09-15-2014, 12:51 PM
#16
I you sure they aren't 12580681? http://r.search.yahoo.com/_ylt=AwrBT...VyE16hpOFQgLE- https://search.yahoo.com/search;_ylt...fr=yfp-t-901-s
