I'm trying to get my car started after replacing the pick-up, fuel lines and installing an NOS Delco fuel pump and I can't for the life of me get any fuel to the carb. I dumped little cups of fuel into the carb to "prime the system" like I've read you have to do, but after an hour of doing this and cranking the starter I still can't get any gas at the carb inlet fitting. I'm afraid I'm going to wear out a new starter. I checked the fitting at the sending unit and gas is getting out of the tank, so the fuel pump is making a little progress. Do I need to be more patient and keep doing what I've been doing or get a new fuel pump because my NOS pump's seals have gone bad over time?

Thanks for any help.

I forgot to mention that I'm using a mechanical fuel pump, and yes, I know they aren't very good at pump fuel vapor or air.

If your 101% certain you don't have any leaks anywhere from the pickup sock to the fuel pump's inlet that could be letting air IN (and thereby negating the fuel pump's suction)......

And your also 101% sure there are no obstructions from the sock to the pump (not allowing fuel to flow).......

And your likewise 101% sure that the pump's operating lever is being properly pushed by the pushrod that's supposed to operate it.......

Then yeah, your NOS pump may have a dried out diaphragm or check valve......

I also replaced the fuel hoses and clamps, and the lines are on so tightly they are very difficult to pull off to check for fuel. I don't see how I could have any leaks in the system allowing air in to break the vacuum since everything is new and put together so tightly. I think I'll go get a new Standard (made in China) pump, which is the best I can find locally, tomorrow to see if that fixes the problem.

This NOS pump I got is so old it still says "AC" on it. When did AC Delco quit putting that on their fuel pumps? I think it's been a while, so this pump was probably in storage for several decades before I got it.

I would NOT replace it with a Chinese part. No car part manufacturer should even be using Chinese factories. I have had my best luck with Taiwan parts, but Mexico seems to be next best right now.

See my post #7:
https://www.thirdgen.org/forums/tech...ml#post6546279

Did this engine come stock with a mechanical fuel pump?
What year is the engine and is it a stock cam?

I’d test fuel pump first. Disconnect the fuel pump supply hose(think it 3/8). It’s the bigger one. Get a 4-5 foot long hose and install it on pump. Then other end of hose put directly into a gas can. This will determine if it’s fuel pump to carb issues. Or sending unit to fuel pump issues.

If it still wont feed the carb get new fuel pump or make sure pump pushrod is all good.

I would suggest a Carter m6626. Made in logansport Indiana USA. Great pumps I put them on everything.

What year make model do you have by the way?

It's a 1989 Camaro with a 350 TBI truck engine that some previous owner swapped in. The car was a mess when I bought it (see my other posts) including the fuel system which they tried to convert to an Edelbrock carb (which is a design that dates back to the 1960's). After ruling out recreating the TBI system due to the complexity and cost I decided to just make it similar an earlier carbureted Camaro, so now it has a non-computerized Quadrajet on a stock GM intake manifold.

I don't see how it could be a sending unit issue since this is new. The only thing is I had to get a TBI one (because that's all that's available at a sane cost) so I put a piece of tubing in place of where the fuel pump is and connected that to an older style Camaro strainer ("sock"). I don't see how that would prevent the fuel from being sucked into the fuel lines. I was very careful to make sure the tubing that went into the sock was the right length so it would seal off the fuel (I even angle cut the end just to make sure).

The Carter M6626 fuel pump is was I meant to say in my above post that I referred to as a Standard made in China pump. I actually bought one of these before I got my NOS one and I returned it because it said "made in China". I would venture to guess that that's where all these kinds of parts are being made nowadays. The only way to get US made parts any more is to by NOS (or NORS) ones, and then take your chance that they are still any good.

Before I installed my NOS fuel pump I made sure the pushrod (that I had to buy and install due to it being a TBI engine) went in and out of it's bore like it should (to make sure the cam even had a lobe on it for this). It went in and out a good distance, so I feel it's working as it should.

BTW, Taiwan is part of China. At least that's what the rest of the world thinks.

There website says “there pumps are proudly made in USA”. Now I see that’s only for new oem electric pumps for cat,case ih,Cummins etc…. Deceiving bastards. lol

But regardless if you plumb the fuel pump directly to a gas can it’ll tell whether fuel pump is at fault.

It's not going to pump anything if there's no cam eccentric or fuel pump push rod.

It appears that taguy has already got this covered

I originally was going to go with an external electric pump, but I couldn't find a place to mount it to my satisfaction since everything around the left side of the gas tank is so crammed together on our cars. It was then I decided that since this engine block had a fuel pump block off plate I would take it off and see if the provisions for a mechanical pump were there, which they were. Then I got a pushrod and made sure it would go in and out, which it did. It was then that I decided I could probably go with a mechanical pump.

How far should the pushrod go in and out on a SBC for it to operate the pump right?

I got the M6626 pump and installed it later today. I was able to get the car to start with it, but the engine only ran momentarily and then quit. I couldn't get it restarted after cranking the engine again for a while while pumping the gas and even holding the gas pedal down. I thought tomorrow I would take the fuel line loose at the carb and put a rag over the end then crank the engine to see if the rag gets wet with gas indicating the pump is indeed still pumping gas. I don't know what to do after that - whether I need to try putting gas directly in the carb again to see if this primes the system, or what. I also never know in these kinds of situations whether to hold the gas pedal down, pump it, or do nothing while I crank the engine.

I converted the carb from a hot air to an electric choke, which is closed completely now due to the cooler weather, if that matters at all in this situation.

One thing I noticed when I was changing the fuel pump was that the pushrod fits pretty snugly in the bore. I could push it in and out without TOO much effort as I turned the engine over by hand, but it doesn't just drop out of the bore on its own. I would think that the return spring in the fuel pump would be able to push it back into the bore when the cam pushes it out, but I guess there's the possibility that it can't and it's getting stuck. I imagine the pushrod bore isn't pristine since this engine never had a mechanical fuel pump and therefore the bore was empty to collect all kinds of gunk and whatnot.

Thanks again for all the good input.

Although I kinda/sorta did a search to see if anyone actually reported this being a problem, well the claim is if everything is clean, it's not going to be an issue. With that said, since your Camaro started life as a fuel injected car, have you visited the stock fuel filter plumbed in the system??? Btw...I would just bypass it for testing purposes.

I just have stock carbureted car fuel lines that go straight from the tank to the pump. Carbed cars never got the big fuel filter in the middle of the undercarriage lie FI ones did. The fuel filter is in the inlet of the carburetor on a Quadrajet like I have.

They were still putting carburetors in 1989 F-bodies from the factory? That's a first for me.

Read the above posts.

Pull the spark plugs, they'll tell you if you've been drowning them with fuel. Don't just dump gas down the carb, use a bottle with a cap and fill the float bowl through the vent on the carburetor and let the carburetor do the metering.
Do you have a vacum gauge? Hook it to the fuel pump inlet side and crank the engine and see if the pump is able to pull fuel. The pushrod usually is very loose and drops down easily. There is a bolt in the front of the block that leads to the fuel pump pushrod bore. If the bolt is too long it will rub the rod. The easy way to replace the pump is to remove the bolt, get the rod in the up position and use a longer bolt threaded in by hand and hold the rod up. Then after the pump is in install the original short bolt with sealer on the threads.

Yes, I know about filling the carb thru the vent hole. I thought I would also check to see if fuel squirts out after filling the fuel bowl and operating the throttle lever on the carb to see if the accelerator pump is doing its job. I pulled this carb off another one of my cars: it is a rebuilt carb I got from Jet, but it was rebuilt a long time ago.

I had no idea about this “bolt in front of block method to hold the pushrod rod up”. I’ll have to try that next time. Thank you for that info. All those years doing it the hard way.

The thing I can't understand about this "trick" is why you even need a longer bolt at all to keep the pushord from dropping down. Why can't you just stick a punch, or some other rod that will fit in the hole, to do this task. If you use a bolt you have to find one that has enough threads to go in far enough to do this, not to mention the trouble involved in threading a bolt in and out of a threaded hole that is most likely all gunked up from not being used.

I pulled several spark plugs and they were dry.

Still no luck getting the car to start, but I think I have some possible causes narrowed down. The fuel pump is definitely pumping fuel up to the carb now, so it's got to be something in and around the carb. I pulled the return hose off of the pump and it was full of fuel: I suspect this might indicate that the fuel isn't able to get into or flow normally thru the carb and is being routed back to the tank when the fuel pressure gets to a certain point inside the pump. I put some more fuel in the fuel bowl and tested the accelerator pump and this seems to be working. I need to figure out if my carb's tiny fuel filter inlet is blocked. I'm wondering if something from inside my new fuel pump broke loose and got caught in the fuel filter inlet, which is why the car started yesterday but quit after a few moments and couldn't be restarted after that.

I may just plumb in a regular inline fuel filter and do away with the little filter inside the inlet of the carb. I'm not a big fan of that design anyway. For one thing it's very hard to get the fuel line-to-carb fitting threads started. Also, the large fitting that the filter goes in is very easy to crossthread - then you've basically ruined your carb unless you can make one of the repair kits for this mistake work. I've worked on Quadrajets that literally had two sets of threads going in the the carb inlet: one correct and one at a slight angle (crossthreaded).

If it's not the fuel filter then I figure I'll just rebuild the carb since it's probably been close to 20 years since it was last rebuilt. It could be that the float has gone bad or something of that nature. If I remember correctly I got this carb for my '78 Firebird (with a Chevy engine) from Jet as being one of their superduper rebuilt Quadrajets. I had a Holley rebuilt Quadrajet before that that didn't seem to work out for some reason, so I sold it at a swap meet. I also seem to recall getting one from Autozone that didn't work at all (big surprise). I think it was around this point in time that I started rebuilding them myself and had better luck doing this.

Might be something as simple as, the carb inlet filter is installed backwards. Those have a little check valve in them, intended to prevent fuel from siphoning back out of the carb when the engine is off. Put it in backwards and you get a blockage.

No, I'm not that stupid.

That "trick" doesn't work for me. That bolt hole in my GM Goodwrench 350 crate motor is blind, so a bolt doesn't go all the way through.
Fortunately, it's really pretty easy for me to get a finger in there to push the rod up as I am inserting the pump arm. I've done it twice now...

That's the way this engine seems to be, too.

Sorry I offered to help. I'll know better in the future.