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Opinions needed - Performed Optical Bump

ak diesel driver said:
Did you replace the OPS when you did the relay mod?
Click to expand...
yes, all new OPS. that was one of the thing I tested to make sure it was working when I discovered the lift wasn't working this weekend. had my son cycle the key while I was testing for power at the pump. then found my goof up with the ground disconnected !! now that the lift is working, pressure isn't looking too good.
 
I'm going to have to look and see if the old pump was a GM EP309 I took off. I just found the flow and pressure ratings for it and for the carter I bought last year on Rock auto. both pumps are listed by application for my truck.

looks like the EP309 is 35gph and 6-8 psi and the Carter P74143 is 20gph and 1 psi since it still worked when I replaced it, I might just swap it back to see if that temporarily fixes the problem.

Maybe this is another one of my Goof-Ups!!

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Fuel pump question. Which one is best for my truck? Looking online the EP309 is rated at 8 psi max and the EP158 is rated at 14psi max. I looked at my old pump and it’s a EP309 but i tried it and it won’t pickup any fuel from the tank.

this afternoonI tried swapping it out to find it’s bad. Since I wasn’t getting fuel I swapped it back and still no fuel so I used my compressor and blew back into the line going into the tank with the cap off. Something must have blew and all I hear is air coming up the full neck. No gurgling like I would expect similar to a straw in a cup bubbling. Something is ether rusted through or blown on the pickup tube in the tank!
Just ordered a new sending unit / pickup tube assembly for the tank that should be here in Thursday, just need to make sure I order the right lift pump.
 
Take the screen off the replacement pickup tube assembly and leave it off. The OEM screen has a bypass valve in it.

If you see a bunch of silver strips: that's the tank lining coming off, plugging things up, and you will need a new tank as well.
 
Yup, could be the sock filter in the tank. Get rid of it and install an inline filter between tank and lift pump. I use NAPA filter 3270, it's a simple 120 mesh screen filter that fits 3/8 hose, just cut the steel line and splice in using rubber hose.
 
dbrannon79 said:
Yes, with the remote mount filter I have and eliminated the original filter manager, it uses 3/8" line from the steel line from the lift pump to the IP, but I have not enlarged the fitting that's in the IP. that was the last step, I just need to buy a fitting for that.
Click to expand...

So double check the 3/8” hose being compressed onto the 5/16 fitting. Wrong size hose is a common point for air ingress.
If you get some good pressure from the other lift pump, might see a fuel leak there. And yes Rockabillyrat is correct restriction of bad LP restriction could cause aeration too.

On the lift pump get the ep158. Yes to all above- drop tank, clean- might need replacement. Remove in tank filter (aka sock) and use external pre filter before lift pump. While tank is out - inspect both metal fuel lines VERY CLOSELY. Rusted lines above the tank is way common. Any rubber line you install should be sae30R9.
 
Thanks guys! I will order the AC Delco EP158 lift pump and start pulling the tank, install a inline filter between the tank and the LP and remove the sock from the new pickup tube. I really hope I don't need a tank too!! Also will get the fitting replaced with the correct size for the 3/8" hose on the IP. :)
 
real quick question before I place the order for the LP. I just stumbled across an AC Delco EP1000 pump that supposedly is for the 98-2000 model 6.5 trucks. it's ratings are 35gph and 8-12 psi where the EP158 is 35gph and 9-14 psi. not sure on the application for the EP158. both are the same price. is the EP1000 an upgraded design on the later years and is that better to go with?
 
Not in my experience. Some of us got together and did testing on a bunch of inline pumps. The 158 had best pressure & lasted the longest.
Gonna say this again- super critical here- ONLY get it from an authorized AC Delco reseller.

Be clear you want to know how to replace it if it fails under warranty and note the day the warranty is up on paperwork. Take the time to test it and get it replaced when it fails to meet spec a couple weeks before warranty is up- as most all the pumps will. Some places will issue a new warranty with the new pump- take advantage of that if they do. This pump design is low cost not long term.
 
Thank you @Will L. EP158 it is. I placed the order through Amazon, I've had a pretty good experience getting GM parts from them ( I do have to watch what I buy from them and look carefully at the reviews) on warranty usually AC Delco has a limited lifetime warranty, but I have never had to do a warranty claim through them. I do however plan to order a spare later through my local Advance Auto store which I know carries a lifetime warranty and they don't ask questions. this way when ether one fail I will go back to Advance and get an exchange, always keeping a spare on the truck. I have a commercial account with them that keeps a record of everything I've bought too. Trust me, if the one I just ordered shows up and just happens to be a chinese knock-off in an AC Delco box, I will be sending it back and heading to Advance! it was $55 vs $89 through Advance.

Here is the link to the one I ordered:
AC Delco EP158 LP
 
As an Amazon Associate we earn from qualifying purchases.
Nope. Cancel it imo.
Amazon is the main place AC Delco said they were trying to sue.
That is where they have the most knock offs, and they have to cut it open in their lab to tell the fakes.

Idk if advanced auto is an authorized dealer or not. Call AC Delco to find out. Last I spoke to them there was 1 and only 1 place that was authorized through Amazon,under the name AC DELCO but spelled a specific way which I don’t remember off hand. He pointed out 2 others that were spelled differently and both were known selling knock offs. and he said NO OTHER ONLINE SELLER WAS AUTHORIZED.
 
Not sure if this is what you were referring to on AC Delco, but I found this site that outlines a list of unauthorized sellers. I also found a price list the sellers have to abide by from AC Delco. I didn't see this Amazon seller on the unauthorized list and also cross matched some of the parts on the price list to see and they seem legit. But I hear you loud and clear on fake copies that you have to cut open to find out. I remember all the chineese iphone copies that were on the market a few years back. they would so good of a copy that you really had to have a good eye to find the differences. this is very good info, I will find out if this seller and also the Advance store are in deed authorized sellers. I think a full list of all the authorized sellers would be a nice piece of info to share.

AC Delco Unauthorized sellers
 
You aren’t getting it. Lets say the first company on that list: 2040ah blah- they are on the list so they eventually loose enough sales. They simply open another business name. Where I live that is a $5 fee, in Las Vegas it is $25 fee. Now they can call themselves “greatest parts place that ac delco loves” and start selling. After enough people get ripped off, after a big enough law suit is pushed against actual AC Delco, then that new company name gets added to the list.

That company you linked via Amazon is NOT listed as an authorized dealer either. So maybe it is real, maybe it is junk.

The complete list of online companies advertising AC Delco parts I would trust:
AC Delco
AM General
Then the AM General authorized dealers since AM General is listed as one
Leroy diesel
Real4wd
Rubber duck
Unique Diesel

I don’t trust predator or us engine products because both have proven not trustworthy.

good luck.
 
And the saga continues. just got the tank dropped and well... it doesn't look good. even the sending unit piece is melted. the top side of the tank was covered in what looks like powder from a fire extinguisher. the upper part of the inside of the tank has surface rust, but isn't as bad as some I've seen before. what on earth would cause the gauge part of the sending unit to melt as if it somehow shorted out!. I'm guessing at this point I need a new tank. this I think is a 24 gallon tank, if I do replace, will a larger tank bolt right up without any mods needed? and will the same sending unit work? here are some photos I was able to take with my phone of the inside of the tank and of the sending unit. I didn't see any problems with the pickup tube it self or the rubber lines that were connected to the pickup tube lines.

the really rusty photo is the filler tube in the tank. I will have to get my mirror to have a look at the top side, but feeling it with my fingers it didn't feel like the filler tube was.IMG_1814.jpgIMG_1815.jpgIMG_1816.jpgIMG_1817.jpgIMG_1818.jpgIMG_1819.jpg
 
I may be wrong on the size tank, looking on Advance Auto by application it shows two tanks. a 25 gallon that measures 14x48" and the 34 gallon that measures 14x62". I measured mine and it's 13 1/4" tall at the highest point (by the lockring) and 61" long from crimped edge to edge. it also looks to have about 1/4 tank of fuel in the tank and I was thinking it was about empty going off of my mileage reaching 300 miles per tank (gauge has never worked) looking at the pictures on their site, it looks the same as the 34 gallon.
 
yeah I'm pretty sure it's a 34 gallon tank. looking more into it the measurements and all plus the amount of fuel left in there.
I got my mechanics mirror and had a peak if the top side in the tank and it's not bad at all. there is a bit of surface rust that has formed but the worst area is the inside of the steel fill tube.

what should I do? run it or get a new tank? rockauto shows a Spectre 34 gallon tank for slightly over $100 and I can order one through Advance for $117. but again it's not GM branded. I really don't want to spend $400 + from the GM dealer for one! I did a google search on the Advance part number and it's a Dorman tank that they're offering a limited lifetime warranty which most likely doesn't cover rust lol.
 
aside from the question to reuse my tank or not, I was reading up on what might have caused the gauge sender to melt inside the tank. I remembered on the old school vehicles there was a power resistor mounted on the inside of the firewall that was for the dash gauges. on my truck I have had the instrument cluster apart to repair the tach and I also have another donor cluster from a gas truck I had used some parts from to repair mine. I noticed that each gauge has a resistor mounted on the power studs inside the cluster. I have not messed with the fuel gauge but I am wondering if something in the cluster may have caused the sender to burn. I took my multi-meter and checked the power output at the harness where the sender plugs in and I'm getting 8.74 volts and will also make my test light glow. my fuel gauge also always stays just below 1/2 tank reading. when I cross the two pins in the connector the gauge moves to the point where it can contact the gauge needle below it. when I go to install my new sending unit I really don't want to burn it up too. is there something I need to check at the cluster before hand?

I also want to add that when I repaired my cluster before, there were several noticeable giveaways that someone else has had it apart. the section where the SES light and STS light are, the plastic divider that directs the glow from the bulb was broken out with pliers along with other pry marks where someone tried to pry the cluster apart. I ended up using the light divider and other plastic pieces from the donor cluster to make mine whole again. should I start by swapping out the fuel gauge with the one in the gasser cluster or will it use a different resistance for the sender?
 
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