Spider Injectors Clogged Completely

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

jce98

OBS Enthusiast
Joined
Jan 13, 2023
Messages
72
Reaction score
52
Location
Austin
Innoperative / clogged spider injectors could never prevent the fuel you poured in from reaching the cylinders.

Here is what they look like in their ports / place.

You must be registered for see images attach


You must be registered for see images attach


Above is a V6, the V8 is the same idea:

You must be registered for see images attach


Hope that helps.
Thought the same, but I pulled #2 & #6 plugs and they were bone dry.
 

jce98

OBS Enthusiast
Joined
Jan 13, 2023
Messages
72
Reaction score
52
Location
Austin
"Fuel pressure good at the valve" = what is the actual reading? Not just pressing the valve to see if there's fuel.

Richard
I have not checked actual reading yet. But it is a healthy spray out of the schraeder valve.
 

GoToGuy

I'm Awesome
Joined
Sep 16, 2020
Messages
2,934
Reaction score
3,409
Location
CAL
A healthy spray does not indicate required fuel pressure. That just tells you there's fuel. But is it min Max to operate and atomize. A bigger question if you have spark, and dump fuel in intake why no light off? Not even a backfire from bad or off timing?
 

someotherguy

I'm Awesome
Joined
Sep 28, 2013
Messages
9,784
Reaction score
14,138
Location
Houston TX
I have not checked actual reading yet. But it is a healthy spray out of the schraeder valve.
If I've said it once I've said it a million times because it's true: Vortec small block is super picky about fuel pressure. Once it gets marginally low, it does not have enough pressure to force open the poppet valves in the spider injector setup. It only takes being a few psi low. This is why one of your very first troubleshooting steps is to confirm fuel pressure with a proper gauge. They're not expensive and it's super easy on the Vortec since they were nice enough to provide you with a test port, unlike TBI's.

Richard
 

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
5,890
Reaction score
7,539
Location
DFW, TX
Check for spark. The spider injection typically just runs like garbage. I haven't heard of anyone with one completely plugged.
The OEM one in my van was completely stuck or gunked shut when I put the crate engine in it after it sat for a year with a blown engine. It ran on ether though.
 

jce98

OBS Enthusiast
Joined
Jan 13, 2023
Messages
72
Reaction score
52
Location
Austin
If I've said it once I've said it a million times because it's true: Vortec small block is super picky about fuel pressure. Once it gets marginally low, it does not have enough pressure to force open the poppet valves in the spider injector setup. It only takes being a few psi low. This is why one of your very first troubleshooting steps is to confirm fuel pressure with a proper gauge. They're not expensive and it's super easy on the Vortec since they were nice enough to provide you with a test port, unlike TBI's.

Richard
Thanks, could not locate my pressure gauge yesterday. Running to get one today. I pulled the intake and cleaned things up, poppet valves looked fine other than the crud on the port. Tested the wire main harness on top of the manifold, getting power. Just as well I could not find my pressure gauge, cleaned the top end up nicely. I did have to replace the fuel line between the back of the block and the fuel filter. I should probably check and make sure those are tight as well.
 

GoToGuy

I'm Awesome
Joined
Sep 16, 2020
Messages
2,934
Reaction score
3,409
Location
CAL
Do you have original poppet injection or upgraded ?
 

kennythewelder

Officially Retired, B31-3 (6-G) certified welder.
Staff member
Super Moderator
Joined
Jul 14, 2014
Messages
6,496
Reaction score
9,087
Location
Louisiana
First of all, you need to check fuel pressure with a gauge. It needs to be over 60 PSI, pre start, for the fuel to get pushed through the popet valves. When you turn the key on, the ECM only cycles the fuel pump, for 2 or 3 seconds. That's it. Next question, how much gas did you pore down the throttle body ? This is a grate video on how to determine what is going on with a no start.
xc_hide_links_from_guests_guests_error_hide_media
 

jce98

OBS Enthusiast
Joined
Jan 13, 2023
Messages
72
Reaction score
52
Location
Austin
Do you have original poppet injection or upgraded ?
Original poppets. It's a 98 2 door 2wd tahoe, it was stolen about a year ago. I recovered it a couple of weeks ago. Amazingly in tact except for some hot wiring and trying to install halogen headlights without a ground. Once I got it back all grounds were cut along with fuel and trans lines removed. I thought the thieves must have started to pull the engine, nope. They had installed a different 5.7. I was able to rewire everything and security light goes off after 3 seconds just like it should. New ICM, coil and crank sensor. Good spark jumping from plug. Next step is to check fuel pressure at rail, should have done that earlier but could not locate my gauge.
 

jce98

OBS Enthusiast
Joined
Jan 13, 2023
Messages
72
Reaction score
52
Location
Austin
First of all, you need to check fuel pressure with a gauge. It needs to be over 60 PSI, pre start, for the fuel to get pushed through the popet valves. When you turn the key on, the ECM only cycles the fuel pump, for 2 or 3 seconds. That's it. Next question, how much gas did you pore down the throttle body ? This is a grate video on how to determine what is going on with a no start.
xc_hide_links_from_guests_guests_error_hide_media
Thanks!! That is my next step is check the pressure. Hopefully check that today.
 
Top