Hello all, I have searched and read all that I can find on the board about fuel pumps, but I guess I am looking for more details. (If there is a post I missed that explains everything let me know). I have a 72 GS convert, and I am pretty sure my fuel pump is bogging everything down. It might even be original as jsut about everything in the car is. Questions: 1. Where is it? 2. Any special tools required? 3. Suggestions on a replacement/upgrade? Thanks guys!
1. there should be a hose running from your carb, to a fuel filter, most likely, then another hose to your fuel pump. then another hose to your fuel line (metal probably aluminum i think...?) i didnt use any special tools on mine. but i think in the old days there could be a fuel pump in the actual tank...dont quote me. my .02 cents
There is no tank pump! The mechanical fuel pump is located on the drivers side at the front of the engine. Just follow the metal fuel line from the front of the carb down and you will see where it enters the fuel pump. Remove the metal fuel line with a line wrench 5/8" I think. Remove the one or two rubber fuel lines at the bottom. See if you can get pinch clamps to stop the flow of fuel or you will have a mess. you will probably have fuel all over you anyway when the metal line drains back. After all lines are removed remove the two bolts attaching it. They may be difficult to get a socket on without proper extensions. After screws are removed pump will want to push out as arm is spring loaded and is pushed on by cam fuel pump surface. Scrape all old gasket material off. Put new gasket in place after coating with a little RTV. When you push in new fuel pump makes sure arm goes back in the samer position under the cam. It will resist somewhat and may fight you as you try and put screw back in. Do not overtighten screws as they are easy to strip. re-attach all fuel lines and you are good to go. All my experience is with 455's but 350's I think are pretty much the same. You sound like you may not be to comfortable with this so maybe you should consider having someone else help you. Hope this helps Good Luck.
thats what i meant to say, but poorly.... i thought way back the fuel pump could be located in or near the tank...not on buicks, but like fords or chevys....i dont know, maybe im confused...afterall im only 21. glad someone else had a better explaination
Pretty much all modern cars have electric fuel pumps located in the gas tank. All the vintage American cars used mechanical fuel pumps mounted to the engine.
Thank you all for your responses. I am comfortable doing just about any engine/car work, I have all the proper tools in the shop, I just wanted some details on replacing the stock fuel pump. And thanks to you all I now have that info. I was just getting confused because everytime I talked to someone, I got the drop the tank answer or the front of engine answer. And since I have not replaced the fuel pump on the GS before I wanted to make sure I was working on the right end of the car. I have some pinch type clamps, and a mess of sockets, extensions, and elbows so I should be fine in that department. When I rebuilt the car originally (6 or 7 years ago) my Dad helped me, but he now lives in Florida (I am in NJ) and have no one to mentor. I have been going through the car fixing and upgrading all of the stuff we skipped during the original rebuild. It has always run fairly good, but it seems like it is starving for gas so I thought I would takle the fuel pump. Last year was the cooling system, this year it will be the fuel system and the tranny, and maybe some carb work. Thanks again for all the responses, I am going to replace it on Friday. I will let you know how it goes. :TU:
Also crank the motor over until it's at TDC, in this position the pump arm has the least load on it. It can be hard to get the bolts installed on reinstalliation. Dave B
Theres only one caveat to that statement with Buicks- the 69 Riviera has an electric fuel pump mounted in the tank. :Smarty:
Alright, I have to ask a stupid question, how will I know it is at Top Dead Center? What should I look for? Sorry for the silly question, as I mentioned above I am comfortable doing just about anything, but I am not so good with the lingo. I know what TDC is just not how to get to it.
Sorry, just rotate the motor until the timing mark on the vibration damper is lined up with the 0 degree mark on the timing tab on the front cover. In this position #1 cylinder is at TDC/top dead center ready to fire, or its on TDC of #6 cylinder. The crank rotates twice for every one rotation of the camshaft. Once the mark is lined up remove the distributor cap and note where the rotor is pointing. If it's pointing at #1 sparkplug wire your where you need to be, if it's pointing to #6 sparkplug wire you need to rotate the crank one more turn until the timing marks line up again and you'll be there. There's no such thing as a dumb question! :TU: Dave B
Definately put the engine at TDC. I have alway found it easiest to get it there by putting a 1 1/8 inch socket on the bolt in the vibration dampener and rotate the engine with a my 1/2 inch drive ratchet or with a pull bar. Disconnect the battery before doing any of these repairs just as a safety measure to prevent any accidental sparks since you are going to have gas in the open air. I also put a bolt in the rubber fuel line and return lines going to the tank and just lightly tighten the clamps on them to keep the fuel from coming out. I would also put a pan or small bucket under the fuel pump to catch the fuel coming back from the carburetor when you take the line off, it just makes for a neater repair. It has already been mention not to overtighten the bolts when you put them back in. Be careful not to cross thread them either, it is easy if you don't have things lined up real well when you put the new one on. You are going into an aluminum cover and it is easy to strip them out. Good luck! :beer
Thanks guys, real good info. Does anyone know how many foot pounds I should tighten the bolts to? I have been dying to try out my new torque wrench........... I am also doing some carb work so if anyone knows how much those carb bolts should be tightened I could use that too. Thanks!
I did not find the sheet that had those figures listed but I seem to remember them to be in the 12 to 15 ft. lbs. range. The carburetor can take more torque but remember to tighten it evenly, alternating corners when tightening it to prevent warping.
Check out this thread. http://www.v8buick.com/showthread.php?t=97948&page=2&pp=10&highlight=torque Dave B :beer
If you are having fuel delivery issues, don't overlook the possibility that your fuel filter might be clogged. And while you are taking lines apart, it will be a good time to replace that anyhow. -Bob Cunningham
I like the way you think Bob. An update: I could not get t new fuel pump in time to install today. I have to order one, so I am thinking a high flow from summit (anyone have any suggestions?). While under the car looking at the pump I noticed something not so good. I had a kinked fuel and return line (rubber hoses)! So I replaced them, what a difference :3gears: . I am not getting anywhere near the same kind of bog down I got before. I am still going to replace the pump as I am pretty sure it is original. While I was at it I finally installed the TH700 tranny adapter plate and changed the oil to the Shell Rotella T with a little lucas. She seems to be running great now. I am not sure if it is my imagination but between the fuel lines being replaced and the adapter plate I got a little more get up and go.............. My fuel filter is pretty new, but I will check that as well. Thanks everyone!!!!!!!!!!!!!!!!!! :TU: :TU:
Your biggest concern about a pump that isn't standard is the physical dimensions if you still have the original metal fuel line from the pump to the carb. The stage 1 fuel pumps are physically longer and require a different fuel line. Check to see if the size of the Summit pump is different from stock. :beer
