Introduction: Poor Mans Repair Guide for Chevy,GMC Vortec Fuel Injector Spider or CSFI System

Picture of Poor Mans Repair Guide for Chevy,GMC Vortec Fuel Injector Spider or CSFI System

I hope I can take some of the Dark Voodoo power away from the notorious Vortec injection spider. If your reading this then  like I did you have been searching  the web and under the hood of you GMC Jimmy, S10, Astrovan, Or Chevy Blazer trying to figure out what to do about that crazy injection system in your truck. Well you have a few choices
1. Buy a new spider set for a small fortune.
2. Buy a "MPFI" retrofit system for about $300.00
3. Try Replacing individual injectors or "poppets" 
4. Junk the p.o.s. the front end is falling apart anyway.

or you can

5. Spend about $16.00-30.00 and a few hours of your time and fix it like I do.

This guide explains how to clean/repair  leaky or stuck poppet valves/injectors. only continue if you are sure that your injectors are getting a signal from the ecu and are actuating. if your not sure, Google it, do your testing and come back.

I am not responsible for any kind of damage or injury you may cause yourself or your car.  Messing around with a fuel system is dangerous, gasoline leaks can and will cause fire and or explosion. Be Safe, Be Smart, Or be Dead.

Step 1: Take a Look at the Injector and Get You Stuff Together

Picture of Take a Look at the Injector and Get You Stuff Together

At this point you have pulled the injectors from the fuel meter body, you have your injector reseal kit with all of the o-rings napa and everyone else has them .
napa's part is....

Fuel Injector O-Ring Kit
Part Number: BK 735359

Make sure the meter body has no cracks, this can be fixed in a pinch, Google plastic welding with soldering iron.

Make sure the black plastic tubing is not cracked or too brittle to be reinstalled. They need to be able to hold 60lbs of fuel pressure. If in doubt take an old piece of  tubing to the local auto parts store and get some double walled plastic gas line tubing. Ford uses quite a bit of it, as does BMW.

You will need the following in addition to your o-ring kit

1. Carb Cleaner
2.Sea Foam in a can "Deep Creep"
3. A Pot O Boil'in Water and or a Heat Gun "Heat gun is faster but water is safer"
4. A Few pairs of needle nose pliers
5. An air compressor with blow gun.
Optional but highly recommended is an ultra sonic jewelry cleaner  "got mine for $30.00 from harbor freight, for the wife......."


Step 2: Heat the Tubing and Pull the Poppet Out.

Picture of Heat the Tubing and Pull the Poppet Out.

With this step be patient, you need too heat the black tubing right at the poppet to just the right temp. the safest way to do it is to dip the  last inch or two in a pot of boiling water for about a minute.  
As soon as you pull the poppet out of the water start to work it out of the tubing with two pairs of pliers.
Be very careful not to scratch the poppet or break the hose. Don't squeeze to hard on the poppet or you will crush it an then you might as well buy the MFI kit cuz the cost about $80.00 a piece.
You will only have a few second at a time to work the poppet out before it needs to go back in the pot. Be gentle and it will come out.
If you are using a heat gun it only takes a few seconds to work it out, but if you over heat the tubing it will become brittle and increase the chance of making your problem much worse.  

Step 3: You Got It Out! Time to Clean It.

Picture of You Got It Out! Time to Clean It.

Great you got that tiny little thing out!
Don't lose it!!!!
Now it is time to test/ clean it.
You might have a better way to do this but the poppet fits perfectly in hole of the rubber piece of my air compressors blow gun.
The poppet is designed to open at about 40lbs of pressure. So l like to start there.
1. Set your regulator to 45lbs.
2.Insert poppet into blow gun nozzle, or ring up some rubber tubing and clamps to hold firmly. The last thing you want is for the poppet to be shot across the garage never to be seen again.
3. Give it a 45lb shot of air. if the poppet opens then obviously it is fairly clean. most likely nothing is going to happen. 
4. Take the blowgun from its quick connect and fill it with carb cleaner.
5. Give it another shot of air, if nothing crank it up to 60lbs. and try again. 
6. When it finally gives way repeat the procedure until you are satisfied that it is clean.
7. Switch to the deep creep and repeat a few more times."the deep creep will remove varnish an keep everything from flash rusting." 

Step 4: Put It Back Together

Picture of Put It Back Together

Now all thats left is getting the poppet back on the hose.

1. Heat the hose like you did before. Heating only the very end will help you keep from kinking.
2. Slowly press the poppet back in, don't rush it.
3. let it fully cool and give it a few good tugs to make sure it set.

The O-ring set comes with instructions follow them.

 Make sure you don't have any leaks before you seal up the upper intake manifold!!!
Drive around for 50 or 60 thousand miles and repeat the process and save some hard earned cash.


Dave85 (author)2015-03-08

I had a problem with injector 8 showing as a p0308 misfire. So l replaced everything plugs, wires, distr cap, rotar, ignition coil, and the problem still remained. I took mine to a dealership because I wanted to be absolutely sure it was the injection. After a quote of 1300 bucks, I decided that I could do the job myself. From the pics below, you can see that the fuel leaked into my intake and was burned leaving a residue. I highly recommend an MFI upgrade as I've noticed an increase in the MPG and HP. I did the replacement following a youtube video and I wanted to give back to the web community. Thanks.

JeremyS170 (author)Dave852016-09-01

I have a p0300 random misfire and ive changed everything. Plugs ,wires , all vac lines. Distributor, fuel filter clean maf sensor egr valve manafold gaskets uper and lower and valve cover gaskets. Still cant get the check engine light off. Could this be my problem?

JoeV24 (author)JeremyS1702017-02-19

One of the problems I've faced on these units in my shop and the mileage idea is just wrong as I've got 340K miles on my 2000 Astro and so far no repairs other than one fuel pump.

One oddball problem with a code P0300 is the manifold pressure/vacuum regulator on the side of the spider. They will occasionally rupture there and even though the engine starts well cold, once warmed up and restarted, it will be flooded and pop a code like you have.

This causes all sorts of thoughts that there's a problem in the ignition system which is an easy primary voltage test. That's usually a red herring.

I can't believe that this is such a mystery. Changing batteries and starters is so 'way out in let field that I shudder at the sheer expense of not doing a thorough diagnosis of the real problem first.

Dave85 (author)JeremyS1702016-09-03

Sounds like my issue so I would say yes. I mentioned all that I had done to my truck to the service guys at the Chevy house and they did their diagnostics to find out. Honestly, you get to a point where it couldn't be anything else. If your model is around the same age and mileage (160k) it's likely that the problem is the Spider injector.

ChevyBlazeiT96 (author)2016-10-27

So my 96 Blazer decided she wasnt going to start one day and after replacing fuel pump relays. ignition switch. battery. Spark plugs ans wires. Temp sensor. And discovering it does stay on with starting fluid sprayed but only as long as it is being sprayed.. Im assuming this is my next attempt... Cleaning the injectors? Any advice? My truck starts only once for 3 seconds if that then dies and wont fire up again.. Just continues to kil my battery from more failed attempts to start. No codes either. Although temp sensor snd o2 sensor read INC on i/m readiness check

JoeV24 (author)ChevyBlazeiT962017-02-19

Stop right where you are before you spend any money.

Why didn't you diagnose the system first? It's only nuts and bolts and a man can fix it if they don't just start ripping into the vehicle and their kid's college funds first.

3 second runs is usually a problem in fuel delivery. Get a FI Pressure tester and find out what the pump discharge pressure is, corrected for altitude, of course.

TIMOTHYW1 (author)2017-01-21

The only that I can tell you is follow the instruction & clean the ports where the injections & use a shop vacuum to clean out the valley.& properly torque the upper plenum the factory part has the sequence torque the bolts 1st pass is (44 lbs in) & 2nd pass is (80 lbs in) if in doubt & you have access to a Snap-on or shop grade scanner tool do a do fuel injector test! & after you're done change the oil & filter & add marvelous mystery oil to gas & oil ! & change fuel filter is cheap & by changing can save the fuel pump! a dirty fuel filter can cause the fuel pump cavitation & will burn up the pump connector & watch youtube videos without dropping the tank on the pickup only there are 2 videos

My last tip is Be Safe & take 5 seconds & think before you do something!!

TIMOTHYW1 (author)2016-05-17

Ebay sells for or $190 for a 4,3 eng & 5.7 eng $260 Brand New ! Too much work with trying to fix junk ? i just replaced on both my trucks ! Fyi ! Run marvious mistery oil all the Time!

ZRB0415 (author)TIMOTHYW12017-01-21

Im getting ready to do the same. we have the extact same truck, medium beige s10 zr2

Redbandit72 (author)2017-01-01

I have a 96 tahoe 5.7 vortec an So far after trouble shooting, i have changed distributor cap, fuel pump, fuel filter,oil, oil filter, spider injector an set timing, after all that its knocking can one one please help im up into the thousands an need my truck fixed or i will lose everything. Thanks lisa

Ridesagain65D (author)2016-12-13

I have a 96 Chevy S 10 4.3 that sabatouged. It sounds like rhe timing is off, no real compression and no fuel through the injectors to the manifold. We tried to start it by priming and it worked. after a few days and toeing it home, tried again with either and started a fire. itjjust didnt sound right.

RB01_ett (author)2016-10-28

I have a 2003 Chevy Silverado V6 4.3 Liter engine. Can someone tell me what the white wire, (I think it is a fiber optic) wire that connects along with the Spider Assembly Power connector? Mine is broken and I am wondering how to fix, if it needs to be repaired?? Thank you in advance.

Felixinstruct (author)2016-10-12

thanks for the idea of rebuilding the spider.I was about to purchase a new one when I stumbled on to it.I just wanted to share some info on going an extra step. I used my leakdown tester and adapted a piece of 3/8" copper tubing to it to pressure test the poppets. With this I was able to force carb cleaner thru the injector,hose,n poppets. This cleaned them good. This also helped verify that the poppets were only opening after 40 psi n not sooner.I powered up the injectors using a small 12volt power supply. With the help of a stethoscope,i was able to confirm I had no leaks. I hope this is helpful to anyone else with this situation.Heressome pics.

JeremyS170 (author)2016-09-01

P0300 random miss fire ive replaced everything but the spider. Check engine light will not go off. Could this be my problem?

TIMOTHYW1 (author)2016-05-17

Vacuum for fuel regulator comes intake vacuum

IsraelC7 (author)2016-02-14

is not working 2001 gmc Sonoma

IsraelC7 (author)2016-02-14

I try in a new set of Injector in my gmc Sonoma 2001 4.3 v6

RonnieW11 (author)2016-01-23

What is the red and blue wire plug actually called that plugs into the spider fuel injectors on a 4.3 vortec?

pundsack (author)2015-10-08

need to know where the vacuum comes from that hooks up to the regulator.

MichaelG127 (author)pundsack2015-10-12

There is no vac line. Its inside the intake so its in a vac

Brandon murray (author)2015-09-02

The yellowish part stayed in the injector hole what do I do

Brandon murray (author)2015-09-02

The yellowish part stayed in the injector hole what do I do

Brandon murray (author)2015-09-02

My buddy and i were working on replacing the injectors in my k1500 all of the injectors came out except for one and The injectors sleeve that goes in to the hole came off and won't come out any ideas

Royevatom (author)2013-06-05

There is a semi clear tube liner at least at each end of the tubing. Under heat it collapses when the fitting end at the meter is reinstalled or at the poppet end when the poppet is forced into the tube after being heated. Once this is done you have have had it. It can not be reassembled. Two units down now after removing the fittings from the tubing.
Until there is more information and an address for the issues I ran into I would advise anyone to avoid this means of repair.

Royevatom (author)2013-06-05

Back again, it appears that the cap on the inlet end of the poppet did not come out as it seems to be melted in place.
The engine overheated (plastic heater control valve came apart at weld) after R&R the heads 5,6,7,8, not hitting. I replaced the unit from a yard now 1,5, 7, not hitting.
So either they are clogged or came from an engine that also had overheated.
I would go back to the throttle body in a minute except it is way expensive.
Plastic and engineers have become good friends and left us out in the cold or heat I should say.

Royevatom (author)2013-06-05

Boiling water is not hot enough. It is not reliable enough temp wise.
If you soften the tubing in one way or another enough to get the poppet out there is a cap on the inlet end if this does not come out with the poppet it will be destroyed when you reinsert the poppet. It is easily crushed. Trying to determine which tube the poppet came out of with out the cap is impossible as there is more line resister still in the tube.
Removing the poppet is easy reinserting it requires a temperature close to the melting point of the tubing once past it there is no return.
I have not tried removing the tubing from the metering unit and then blowing thru it to check for function and cleaning.
Better have several units on hand before you try this.

rolavez (author)2013-01-03

Can I vary the pressure thru the adjustment screw of the regulator ?

gtoner50 (author)2012-08-05

Damned if I can get these things back together. Who carries the tube? All the stores I go to have no idea what it is. I can't even find it on line. Now I have to go to the yard and dig up another unit.

elgray03 (author)2012-03-29

Sooooooo happy I found this. My truck has been having fuel problems concerning starting and I thought it was the fuel pump (which needed to be replace anyways), but I found out I have a leak in my injectors. I recently replaced the spider cylinder in my truck because my old one was clogged. The one I replaced it with was used from another engine I have. Now the one I put in my truck has a leak. Would it be easier to fix the leak or the clogged injector?

krhagerich (author)elgray032012-04-01

It depends on where it is leaking. If you have 2 spiders mix and mach parts till you have a good one.

pddonovan2011 (author)2012-01-22

I love this and I did this and it worked, but cylinder #3 still miss fires. Then I bought the after market MPI Set-up. Also Plugs, wires, rotor and cap. Pulled he distributor, cleaned and lubricated it, then had to rebuild it because it was WAY to sloppy! The timing mark danced all over the place, now it is nice and steady. It DID have 96,000 miles on it! BUT, guess what, #3 Cylinder still miss fires. Now I am going to the Dealer too have the wire harness between the Spider and the ECM replaced! If that doesn't fix it then I plan to build a new motor, built correctly, and that will include a custom manifold with real individual injectors. #3 has to stop miss firing, I don't like it!

krhagerich (author)pddonovan20112012-02-12

First check your plug on cyl 3 it is very, very common for this spark plug to cross thread because it is so hard to get to. Next check your compression..If its good you don't need a rebuild. If you have good compression it will come down to a vacuum leak because of bad lower intake manifold gasket..also a big problem with theses engines or depending on what year you have it could be a leaky fuel line "if it enters the manifold from the back of the engine" or leaky fuel pressure regulator. To check this pull the top intake manifold off peek at the lower manifold and if you have any leaks you will see a clean spot where the gas is washing the manifold. Check your fuel pressure as well to see if it is dropping pressure.
They make an aftermarket spider with mini injectors that works great for about $250.00. I have installed full sized injectors in these trucks in the past and to be honest its not worth it.

im2scary (author)2011-10-18

THANK YOU! I was going to tear mine apart and try to clean it, as I have over 200,000 miles on my engine and don't want to dump over $300 into right now. This is going to help out tremendously. I'll let you know if it works for me.

Thanks again for sharing this!

Gathrax (author)2011-08-22

Gm says to clean em' with some specialized equipment and everyone else says to convert to the MPFI unit. Most people assume your willing to dump $300 into 14 year old truck with 200k on it. Great job on giving some info on a question everyone else seems to disregard.

krhagerich (author)Gathrax2011-08-24

No prob...I'm glad someone actually saw this. Its my first write up. I just did a diy transmission rebuild on this truck. I was told by everyone that I would need about $1000.00 worth of tools. I made all of the tools with scrap metal and some brain juice. running great so good in fact that the transmission shop that told me it could not be done wants to outsource some work to me.

krhagerich (author)2011-04-06

Sorry about the poor pics, I will do a video next time I do this.

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