When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
1. is fuel line to tank clogged ( does fuel run out the fuel line when disconnected)?
2. can you detect the rod to the camshaft change position if you "bump" the engine?
3. can you push the fuel pump lever and detect suction?
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Originally Posted by planet-automobile
Hello
1- I installed a hose in a gas can next to the wheel
Gravity feeds the fuel pump, is the can too low and why don't you blow out the supply line from the pump to the tank.
2- I didn't look
3- the fuel pump is working but is very difficult to operate by hand
3- yes hard to pump by hand.
You need an 'S' shaped for the tank line to pump fitting, a regular (not molded) hose will kink.
No one changes camshaft because they think the fuel pump lobe is worn out. Not going to happen. Not enough pressure from the fuel pump spring to do any damage to the cam. Besides, the pump rod usually wears out first.
You have other issues going on. Are you sure the pump "arm" was installed under the pump rod before you tightened up the bolts? I assume you cranked & cranked & cranked and no fuel at the carb?
There are three lines to the pump. Are you sure each line goes to where it is suppose to?
here's what I would do,put the timing on #1 firing order,then stick a rod in the fuel pump opening and measure the distance the rod goes into the fuel pump hole.Take the rod out and turn the engine over about a quarter way,put the rod back in and see if the distance is less(the lobe on the camshaft is highest on #1firing order.if it is your cam lobe is good.Next,on a sall block there is a bolt hole in the frt of the engine in line with the fuel pump rod,take that bolt out and get a longer bolt. put the engine back on #1,put your fuel pump rod in and all the way up,using the longer bolt tighten it up so the rod can't fall.Put your fuel pump on and take the longer bolt outand reinstall stock. bolt.Hook up yourfeed line and turn the engine over and see if fuel comes out the outlet fitting.Make sure you've got a bucket to catch the fuel and disconnect th coil.If there isn't a bolt hole in the frt of the engine use some heavy duty grease to hold the rod up while you install pump.
Ok. Getting back to post #6. Just to make sure everyone's on the same page.
New fuel pump pushrod.
Changed pump.
Tried to operate pump by hand.
Installed pump on block.
No fuel at carb.
Now, how was it determined that there is zero pressure at the carb? Line unhooked? No fuel in bowls?
Last edited by HeadsU.P.; Jul 5, 2019 at 12:44 PM.
Pump is working. It was tested.
Pushrod moved when engine was cranked.
No fuel pressure when pump is mounted.
H-m-m-m-m-. I think I would put both pumps side-by-side on a work bench. Compare not only the arms length but the angle of the arm. Do both arms return to the exact neutral position? Do both arms push down to the same position? They appear to be twins, but if one of the pumps arm is a little shorter, then . . . . . . . .
going back to one of the original questions did you check the line from the tank to the pump for obstructions.
the tank is higher than the pump so gravity will force the gasoline to the pump, priming the pump.
holding a plastic bottle below the pump may not prime the pump.
No one changes camshaft because they think the fuel pump lobe is worn out. Not going to happen. Not enough pressure from the fuel pump spring to do any damage to the cam. Besides, the pump rod usually wears out first.
I beg to differ, and I am not the only one. If that cam lobe has not been properly hardened with the rest of the cam, it could well wear out. Pictures are in planet's post #8, so have a look.
With the fuel pump out it is easy enough to check the pushrod for travel, as was done
I beg to differ, and I am not the only one. If that cam lobe has not been properly hardened with the rest of the cam, it could well wear out. Pictures are in planet's post #8, so have a look.
With the fuel pump out it is easy enough to check the pushrod for travel, as was done
What I meant was, of the 17 lobes, that's the last one you will have to worry about. If the fuel pump lobe is gone the other 16 lobes wore off long before that. Those lobes have 300-400 lbs of pressure and the pump lobe has what, 20 lbs? Somethings not right.
Its my understanding the entire cam is put into a heat treating oven at the foundry to harden the entire unit. How could one lobe not be harden?
Last edited by HeadsU.P.; Jul 5, 2019 at 04:32 PM.
What a great question of which I have no answer. I do not know how far the fuel pump pushrod travels. Never gave it any thought. However, a half inch seems short.
Could be cam lobe. Has to be 10,000 to 1 odds that is the problem. If it is, you have a lot of work cut-out for you, sorry.
