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Setting up my s10 fuel system ?

453 Views 10 Replies 4 Participants Last post by  corvairbob
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ok i'm not hot rodding this but the s10 forum guys are in disagreement as to my issue. i have the 2000 s10 2.2L vin5 truck and i had to change out the fuel pump. well when i did that and got it back running and test drove it i got home and the pressure line blew off the pump. so i put it back but then decided that this may happen again and put me on the side of the road. so i put it on the lift and took the tanks down and got some doorman repair endes. so because i have the old pump and before i installed the new pump i made sure the ports were these same the pressure was 5/16" the return 3/8" and the pressure 5/16" port internal line did go down to the pump i made sure of that. then i made sure the wires were the same colors and that they went to the same spots on the new pump as they were on the old pump. i did not want to have to take down again, and also because i had a time flinging that pump the did not cost 300$

so now to my delema. i got the lines all connected i did one at a time and i used doorman repair end kits and put them back on the pump and then fitted the barbs over rubber gas line. then ar the other end i had to fashion some brake line to fit into the old line at the filter and the rubber gas line. so then i started it and i had a leak parrell to the frame and sure enough it was the pressure line, for some reason it did not like just being clamped to the barb so i had to push it more onto the doorman line so it went over the complete bare and i double clamped it on both sides of the barb hump area. now i started it again and i found a leak at the filter center port so i got a new filter and put it in the same ports. then i started it and discovered the rubber gal line swelling some and i figure that is not good. so i double checked the hose rating and i'm be damned if i use 50 psi rated hose. so i have had a hell of a time findng a fuel line kit for this truck the filter has 2 ports on the tank side and one on the engine side.

so some guys i taked to on the carfix forums and the s10 forums are telling me i have the wrong filter or connected it wrong. so maybe you guys can help me out.

i figure if i hooked the filter wrong it will not allow gas to run the engine as the built in regulator will pass fluid in reverse it industry regulators are on way devices. i worked on hundreds of them in my 40 years. so today to calm the car fix guys i did this test see photos. and here is the filter i have see photos can you guys confirm to me the the center port is the inlet and the outside id the return. one for the carifx guys sen a photo showing the other way so it is possible i have the wrong filter but oth original fitler works as the one photo show. but the s10 guys are telling me i have the wrong filter but the gm parts site tells me by my vin i have the correct filter also if i did have it connected wrong that the engine just would not start and or run? of here are tons of photos let me see if i can get sub titles on top of each one for a description

ok this is the original filter that i tested today

Rectangle Handwriting Font Parallel Display device

this is the original filter that afrer i got the new pump and line installed i found this leak so i change out the filter
Automotive tire Motor vehicle Automotive fuel system Automotive exhaust Automotive wheel system

this is the original filter showing all the lines the rubber on the what i'm calling the inlet was for doing a smoke test to find that leak that turned out the where i have pointed out in the above photo

Hand Finger Gas Nail Drinkware

this is the diagram of how i now have this plumbed up
World Font Computer Parallel Engineering

this is a filter the car fix guy sent me telling me the filter is wrong that i have new and original
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the is the original filter you may see the drip between the barb and the filter
Automotive exhaust Gas Household hardware Nickel Fastener

this is the gm site showing me the fuel line diagram and it sure looks like like 24 goes to the center port on the filter and they said it went there. but i'm getting a lot of conflicting stories.
Font Parallel Auto part Line art Drawing


my new filter with the same type of ports

Automotive tire Motor vehicle Engineering Gas Automotive wheel system


thanks fo r any help on this if i was to take this filter off and do the same test with the air i bet i will get the same results as i do not belive the regulator will allow backwards operation. thanks


Rectangle Handwriting Font Parallel Display device
Automotive tire Motor vehicle Automotive fuel system Automotive exhaust Automotive wheel system
Hand Finger Gas Nail Drinkware
World Font Computer Parallel Engineering
Rectangle Font Parallel Microphone Circle
Automotive exhaust Gas Household hardware Nickel Fastener
Font Parallel Auto part Line art Drawing
Gas Engineering Machine Pipeline transport Wood
Automotive tire Bottle Wood Gas Machine
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Part description says 5/16" return line. That's the one in the center.
I thought 3/8 would be the pressure from the pump, 5/16 the return.
However, your air test says center in as it passes thru, and only doubles back when there is too much pressure (plugged)
One more thing, you're using the wrong clamps and 50 PSI is not fuel injection hose.
yes i figured that out when i saw the line swell up after i started it. i used my remote start when i was under the truck to monitor it and saw what all was going on and then i checked the rubber gas line and sure enough it was rated for 50 psi but the clamps are over the steel line and i have flare on the ends of the lines so it should not pull over the flares

anyway don't use the photo of the filter that says the inlet is the 3/8" line that was a reference photo the carfix guys sent. i did a pressure test ont he old filter you can see in the 1st phote that shows how i did the test and the results

now if the new filter was different then i think the engine would not start or run correct. in the test photo one connection was putting air into the 3/8" port and i got no air for the other ports and the filter swelled up form the pressure not going anyplace and when i hooked it up with the air going to the 5/16" port i got air out the othe end to the engine and when i started blocking that port i got air starting from the 3/8" port on the tank side of the filter

anyway i now have a line set getting built for me and for the just in case i did get it wrong they are sending me 2 push to loc connectors so ir i put the line on and the truck fails to start and run i can cut the lines andswitch them and try again.

i will only work one way thanks
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now if the new filter was different then i think the engine would not start or run correct. in the test photo one connection was putting air into the 3/8" port and i got no air for the other ports and the filter swelled up form the pressure not going anyplace and when i hooked it up with the air going to the 5/16" port i got air out the othe end to the engine and when i started blocking that port i got air starting from the 3/8" port on the tank side of the filter
This would be correct as there must be a one way valve in that filter. Never seen those before.
you know when i was in machine repair all the regulators i ever tested would not allow any fluid flow in the reverse direction if you take a propane regulator they have the same size openings on either end and if you connected it backwards you get nothing i'm all most 100% sure that all regulators work the same in fact ever one i ever worked with had flow direction on the body. but this filter dose not indicate inlet and or outlets my guess is the mfg is assuming all you going to do is take the old filter off and replace it and the size ports make it impossible to get wrong.

but tomorrow to prove this new filter i will run the same test that way i know for sure and when the line kit gets to me i will know if i can just plug it in or have to cut it and reroute them the other direction. thanks
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The pictures you show of the fuel filter is the filter used in 1999 - 2004 Corvettes with a built in pressure regulator set at 58 PSI. Often times people use the Corvette filter when doing LS Swaps. The filter for a 2000 Blazer doesn't have a pressure regulator. Click on below:


Are you trying to adapt the Corvette filter?
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i took off the new filter today and tested it and it tested out the same and yes it was about 58 psi that the air started to come out the the 3/8" to tank line as i shut down the to engine port so i have it figured out now . it turns out the vin 4 s10 is the gas engine and the vin 5 is the flex as most know but for the fuel pump they are way different the ports are opposite sides and the filters ports are different as well it only makes since the gm would make the inlet and return be the same size on the pump and filter no matter what side the pump or filterports are on the mut match feed and return so as to not cross them so i plumbed mine according to that theory and i was correct but the s10 guys and the carfix guys did not get that and told me i was all wet and wrong.

one guy here told me i had the lines and fitting wrong for what i was doing and he was correct i never did this and used what i had and it turned out to be wrong. so it is a good thing i found this out on the lift and not on the side of the road. so i have a line kit being built for me now thanks guys for the help you came thru
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The pictures you show of the fuel filter is the filter used in 1999 - 2004 Corvettes with a built in pressure regulator set at 58 PSI. Often times people use the Corvette filter when doing LS Swaps. The filter for a 2000 Blazer doesn't have a pressure regulator. Click on below:


Are you trying to adapt the Corvette filter?
He's using the filter for the flex fuel S10 2.2L.


With those filter/regulators (or the corvette one which is similar), I usually use an adapter that is the female disconnect on one side and AN flare on the other side. If you have an AN flaring tool, you can flare aluminum hard line to match the AN flare, or you can get a second AN flare to compression adapter to attach to the AN flare.

The adatpers are available at https://www.amazon.com/dp/B07NN3CLSD and from most online "speed shops" (Summit, Jegs, Speedway, etc). You need one 5/16 to -6AN and a 3/8 to either -6AN (for 3/8" tubing) or -8AN (for 1/2" tubing). If you want to run flex hose (rated for the appropriate pressure), hose barbs are https://www.amazon.com/dp/B07K59CT1G/ (3/8 hose) and https://www.amazon.com//dp/B07DXVN9XP/ (5/16 hose).

If you want compression fittings on 3/8 hard line, use https://www.amazon.com//dp/B07BRKBZZM to go from -6AN to a 3/8 tube compression fitting.
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thanks guys i have the tank off and i have a new fuel line kit out for delivery today and it is female to female connections. the kit lines may be a bit long so the guy that built the lines called gastankman on ebay sent some push to lock and mechanical fittings in case i have to shorten it. i ordered it to be 6' long anyway i believe this will do the job.

and the filter i have is like this one on rock auto GM GENUINE GF845 . i tested it yesterday by putting regulated air pressure on the center port on the end of the filter that has the 2 ports on it and that lets air pass thru the filter to the other end and if i start blocking that other end the connects to the engine i will start getting air out of the other port on the inlet end of the filter that is the return back to the tank.

so aside from all that now all i need to do is get the fuel line kit and hook up the tank side lines and evap line put the tanks back in then hook up the fuel filter lines and give it a test start and mace sure it has no leaks and i should be good to go. thanks for the help. you guys helped me out way faster than the s10 guys did. they got hung up on the vin issue. i told then i had the vin5 and the vin5 is opposite from the vin4 truck and they just did not pixk that up. you guys got that fast thanks again i was hopeing some hot rodders would have the answers. thanks again
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