Injector questions... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Roostboy102 · 06-03-2013, 07:46 PM

I've come down to firing my 4.8 swap. At first I couldn't get it to start at all. Pulled injectors and they were fullllll of bad gas turned goop or whatever you want to call it. I "cleaned" them (kerosene soak, carb cleaner, boiled in water for 5 minutes) and it worked (for a little bit). After cleaning them it'll start up with a lot of cranking and idle for 3 minutes or so and then just shuts off. I revved it in that time too and it sounded perfect. Then it just dies. It basically will not start for like 10 minutes but if I give it time then it'll pop right off again and run for a while.

Soooo; here is the question: if I get new injectors could I possibly experience the same thing? I'm running a return system with a factory 01 Silverado fuel filter and an external walbro pump with the factory tank.

Where else should I look. I don't want to drop a whole lot of money for new injectors and then I'm back to square 1 after running it for a little. Any help appreciated guys! Gotta thank you all for getting me this far! Before my C10 and the lsx swap, as far as I went with vehicle maintenance was brakes and oil changes. Learning a lot...

Big Port Jimmy 6 · 06-03-2013, 10:52 PM

I bought a set of takeoffs from eBay. Be aware that there are harness differences, and the injectors have different lb/hr ratings so the tune may need tweaking. Jay

Roostboy102 · 06-04-2013, 04:59 AM

I plan to get the same part number injectors so I would think that wouldn't be an issue!?
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66C06 · 06-04-2013, 10:32 AM

could be trash in the fuel rails or the lines. How new are the tank and lines? Were the fuel rails and injectors new or used? Try doing a seafoam treatment through the fuel system. It will clean the junk out of the fuel injection system.

Roostboy102 · 06-04-2013, 02:09 PM

Tank is original but the truck has been driven ever since it was new. Lines are new. Rails came with the engine. I'll try the seafoam
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NPilot1975 · 06-04-2013, 02:40 PM

Did you have the VATS programmed out?
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Roostboy102 · 06-04-2013, 04:41 PM

[QUOTE=NPilot1975;6107121]Did you have the VATS programmed out?
Posted via Mobile Device[/QUOTE

Yes, it runs for like 5 minutes perfectly fine and then just shuts off.
Posted via Mobile Device

NPilot1975 · 06-04-2013, 04:53 PM

I am pretty sure that is how the VATS works. It lets the engine run for a few minutes then cuts fuel.
Posted via Mobile Device

NPilot1975 · 06-04-2013, 04:55 PM

I would check your fuel pressure or if your pump is cutting out
Posted via Mobile Device

06-03-2013, 07:46 PM	#1
Roostboy102 Registered User Join Date: Jan 2012 Location: Amish Country Posts: 138	Injector questions... I've come down to firing my 4.8 swap. At first I couldn't get it to start at all. Pulled injectors and they were fullllll of bad gas turned goop or whatever you want to call it. I "cleaned" them (kerosene soak, carb cleaner, boiled in water for 5 minutes) and it worked (for a little bit). After cleaning them it'll start up with a lot of cranking and idle for 3 minutes or so and then just shuts off. I revved it in that time too and it sounded perfect. Then it just dies. It basically will not start for like 10 minutes but if I give it time then it'll pop right off again and run for a while. Soooo; here is the question: if I get new injectors could I possibly experience the same thing? I'm running a return system with a factory 01 Silverado fuel filter and an external walbro pump with the factory tank. Where else should I look. I don't want to drop a whole lot of money for new injectors and then I'm back to square 1 after running it for a little. Any help appreciated guys! Gotta thank you all for getting me this far! Before my C10 and the lsx swap, as far as I went with vehicle maintenance was brakes and oil changes. Learning a lot... __________________ 72 C10 - Multicolor, 4.8 ls, NV3500. Sold 72 K5 - Under Construction

06-03-2013, 10:52 PM	#2
Big Port Jimmy 6 Addicted to Rust Join Date: Dec 2009 Location: Abbeville SC Posts: 1,030	Re: Injector questions... I bought a set of takeoffs from eBay. Be aware that there are harness differences, and the injectors have different lb/hr ratings so the tune may need tweaking. Jay __________________ Current trucks: (48 GMC100 320 inliner) Gone (48 Suburban in pieces) Sold 87 GMC CCSB 5.3 4l60E Daily Driver ECTA National record holder XO/PP We never really grow up, we just learn how to act in public.

06-04-2013, 04:59 AM	#3
Roostboy102 Registered User Join Date: Jan 2012 Location: Amish Country Posts: 138	Re: Injector questions... I plan to get the same part number injectors so I would think that wouldn't be an issue!? Posted via Mobile Device __________________ 72 C10 - Multicolor, 4.8 ls, NV3500. Sold 72 K5 - Under Construction

06-04-2013, 10:32 AM	#4
66C06 Registered User Join Date: Oct 2012 Location: Rockwall, Tx Posts: 151	Re: Injector questions... could be trash in the fuel rails or the lines. How new are the tank and lines? Were the fuel rails and injectors new or used? Try doing a seafoam treatment through the fuel system. It will clean the junk out of the fuel injection system. __________________ 66 SWB Stepside: Project C-O6 06 ZO6 MSM 6spd 562/520rw N/A 06 Caddy CTS The Daily 07 Hayabusa - absolute chaos

06-04-2013, 02:09 PM	#5
Roostboy102 Registered User Join Date: Jan 2012 Location: Amish Country Posts: 138	Re: Injector questions... Tank is original but the truck has been driven ever since it was new. Lines are new. Rails came with the engine. I'll try the seafoam Posted via Mobile Device __________________ 72 C10 - Multicolor, 4.8 ls, NV3500. Sold 72 K5 - Under Construction

06-04-2013, 02:40 PM	#6
NPilot1975 Senior Member Join Date: Aug 2002 Location: Plymouth, MA Posts: 891	Re: Injector questions... Did you have the VATS programmed out? Posted via Mobile Device __________________ 1972 Blazer body...need to get a thread started for the rest of the story

06-04-2013, 04:41 PM	#7
Roostboy102 Registered User Join Date: Jan 2012 Location: Amish Country Posts: 138	Re: Injector questions... [QUOTE=NPilot1975;6107121]Did you have the VATS programmed out? Posted via Mobile Device[/QUOTE Yes, it runs for like 5 minutes perfectly fine and then just shuts off. Posted via Mobile Device __________________ 72 C10 - Multicolor, 4.8 ls, NV3500. Sold 72 K5 - Under Construction

06-04-2013, 04:53 PM	#8
NPilot1975 Senior Member Join Date: Aug 2002 Location: Plymouth, MA Posts: 891	Re: Injector questions... I am pretty sure that is how the VATS works. It lets the engine run for a few minutes then cuts fuel. Posted via Mobile Device __________________ 1972 Blazer body...need to get a thread started for the rest of the story

06-04-2013, 04:55 PM	#9
NPilot1975 Senior Member Join Date: Aug 2002 Location: Plymouth, MA Posts: 891	Re: Injector questions... I would check your fuel pressure or if your pump is cutting out Posted via Mobile Device __________________ 1972 Blazer body...need to get a thread started for the rest of the story



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