Anyone got a good fuel pump replacement write-up?

I searched, but did not find anything.

TIA.

 

Depends on what you need the writeup for. Changing out the fuel pump really isn't that hard, depending on if you have a carb model with motor mounted fuel pump, or a EFI model with in-tank pump. Best thing would be to either run down to your local auto parts store and grab the Haynes manual for your Blazer, or fill us all in on your exact specs so that we'll know in what direction to point you in.

 

its a 92, with the intank pump.

 

Mine went out about half a year or so back. I'll type up a bit from what I remember but you might wait for a couple of the other members to fill in any blanks

It went out while I had a full tank. Luckily it worked enough to pump a little, so I jumped it at the relay and took off the fuel filter, then pumped out (excruciatingly slowly) everything in it into another car and a couple of spare gas cans. There are a bunch of plastic brackets that hold the fuel lines in place, I took off the one closest to the tank so i could get a little more play out of the lines. After that I went after the plastic casing around the tank, that one is pretty straight forward. Next came a pretty difficult part since my pump hadn't ever been changed. The rubber pipe running from the gas cap to the tank had to be disconnected. Its got a couple of ring clamps that keep the pipe in place.... these weren't hard to get off, but sepereating the pipe from the tank ended up being a pretty big pain. I think that there is the main one for getting gas into the tank and then another that runs to where the fuel line goes into the tank. After that you need to take off the 2 metal bands that are holding the tank in place. there are 4 bolts holding them in place and from what i remember one of them was at a akward angle so it took a little more attention. Before you take them all the way off you might want to have a buddy or a jack under there to keep the tank in place, it's not heavy with no gas in it but things get difficult when parts come falling down. I couldn't get the tank all the way to the ground while the fuel line was in it, so i lowered it a little and tilted it. Once you've got it in a position where you can work on it, you need to get into the tank. I used a flathead screwdriver and hammer, pressed the screwdriver up against one of the pieces of the ring that was sticking up and gave it a few good hits. You'll still want the tank to be stabilized or else your sender might get messed up (pricey fix). Once the ring is seperated you can lower the tank a little more and pull out the assembly. It should all come straight out with the exception of the float, You'll probably have to disconnect that but its not difficult, just a clip holding it in. Although you should be really careful since that plastic on there is 16 years old now. After thats done you can pull everything out of the tank and should be set for putting the new pump in. Getting the new pump on is pretty straight foward.

It takes a pretty long time but a 12 pack and a helper should make things go pretty smoothly. If I missed any spots yall feel free to correct me. Good luck hombre.

 

A

 

I'll go ahead and write up my experience as well, though it's going to sound remarkably like campesino's description. It is a fairly straightforward process, only that it can be something of a hassle with a tank thats never been dropped and disconnected before. I've got an 86 2.8 TBI, and I'd thought my fuel pump had gone out completely and was unable to pump out the gas that was in it, which made this a major pain in the a$$. I'd highly recommend having a small electric pump available if your pump is completely dead just in case you run into this scenario, as it will make your life so much easier. Anyway, it's been a few years since I've had to drop mine, but you will definitely want to have a helper around, preferably someone who won't complain the whole time . There are the 2 straps holding the tank up, 2 bolts per strap and they should come down pretty easy. You will want to be mindful of the 2 rubber send/return hoses, as well as the main intake hose (aka the one where you fill the tank up from normally). Should just be a few ring clamps holding them each in place like campesino described, and it will likely be an act of congress to get the hoses off once you release the clamps, mainly because you have to remove them before the tank can come completely off and it's sort of a tight spot. I was able to get all of the hoses off with a lot of pulling (hard to do at those angles I must say) and using a flathead screwdriver to pry around the edges of the hoses and "unstick" them from the metal tubes sticking out of the gas tank, and at some point there you'll want to disconnect the electrical connections going to the pump itself. Once (if) you're able to get them off, just lower the tank down easy and slide it out. The pump is held it with a locking ring mechanism with a few tabs sticking up, just get a flathead and a hammer and tap on it in a counter-clockwise direction and it'll slowly back its way out. Make sure you aim the screwdriver near the base of the tabs to minimize the possibility of breaking them. Once you get that loosed, just lift up on the whole mechanism, but do it slowly. I was able to get the entire thing out, with the float/sending unit, and pump and all, you just have to tilt it at a few angles as you're lifting it out to get it. If you are unable to remove the hoses and end up having to try and take out the whole assembly from the tank before you drop it completely, just be very careful and have someone holding the tank up solidly, otherwise you will damage something.

I'd suggest going ahead and spending the few extra bucks (yeah, might be 30 or 40 extra bucks) and getting a decent fuel pump, mainly because you only want to have to do this whole operation once. In my case I thought at the time that I bought a cheapo that didn't perform properly and I ended up having to drop the tank again and do this all over again, but I stuck an OEM replacement in this time. Once you get the whole assembly all out of the tank, just swap out the fuel pump, which should be fairly straightforward. Also, check the rubber gasket at the top of the tank under your ring locking mechanism and see if it needs to be replaced. There should have been one in the fuel pump replacement kit you bought, but you may or may not need it. Sometimes the replacements they send look cheaper than the old one thats in there. Installation is, as they say, the reverse of removal. Stick the assembly back into the tank as it was, lock the ring, being mindful of the rubber gasket.. Especially with the replacement gaskets, because they're so young, they'll want to try and bunch up sometimes while you're locking the ring mechanism back.. Just watch it as you go. Make damn sure that tank is empty, because if you thought it was hard to get the tank off with gas in it, it's friggen impossible to get it back on, even with as little as 1/8 or 1/4 tank. A few things I learned from my experience that its nice to have are a fuel pressure gauge, and a way to lift the vehicle. I ended up having to do this 3 or 4 times tracking down another problem that I thought was fuel related, but the last few times I did it with a lift (a buddy of mine worked at a gas station with a little shop and a few lifts). I must say that having the lift turned a 2-3 hour swearing cursing event into a 35 minute walk in the park, off and on hehe. Anyway, that should be about it, it's been a few years since I did this, and may have missed a few things, but feel free to post back with specific questions.

-daniel

 

Thanks guys, that will be useful info when I do this sometime this week.

So your telling me there is not drain in the tank? That makes no sense.

 

Nope, unfortunately there is no drain. Not sure if that's a theft prevention thing or what. There was one other thing I'd noticed when I was working on my Blazer yesterday that may be helpful on your model. I'd noticed that if I knelt down by the rear driver side wheel, I had easy access to the send and return lines, right where the ring clamps hold the rubber hoses on the tank to the metal lines going to the front of the vehicle. I'm able to disconnect them right then and there, and that might help you out greatly. Also, if there is any life in your pump at all, you should be able to disconnect thesend line (the slightly larger hose, or just disconnect both if you're not sure), and jumper the pump on, stick a fuel can under it and let the pump do the draining for you. The quickest place I'd jumper the fuel pump on would be at the fuel pump relay under the hood. Just stick a paper clip from the hot pin over to the one going back to the pump. Hope this helps!