DocHoliday

Well last night I fired up the car and began to leave and it dies on me. So I start it again and then it does the same thing. Now it doesn't start. So I began to diagnose the problem. I have spark, and I have air. I sprayed starter fluid into the carb. Starts up then dies when the fluid burns off. Took out the old filter to check if it could be clogged. Replaced and attempted startup. Nada. I even unhooked the fuel line at the filter to see if fuel was going to come out. Bone dry. So any suggestions? I'm guessing fuel pump. I hope not. Thanks!

phess11

I would say no fuel:
1. check fuel lines from pump to the tank.
2. if ok, fuel pump.

You probably have a fuel pump on the engine block, and maybe another electrical fuel pump in the gas tank.

DocHoliday

How do I check the fuel lines? And how do I locate whether or not I have a fuel pump on the block?

phess11

This is a pic of the location of the fuel pump. Follow the lines back to the tank to see if there are any breaks or kinks.

Sonix

iTrader: (1)

it's your fuel pump.

don't fret though. on your carbed car a fuel pump is like $30, and takes about 20 minutes with a set of wrenches.

Your HO car *may* also have an in tank electric, not totally sure about that, or how it works. Replace the block mounted fuel pump, then keep the fuel inlet from the carb disconnected, and crank the motor over. If it spews fuel (hopefully into a cup or something), then you're done.

DocHoliday

Well to make a long story short, that solved the problem, for this afternoon. Car ran beautifully after the new pump went on. No more fuel starvation or anything. Then this evening, I was going to Taco Bell, and the same symptoms hit AGAIN. Car doesn't want to start. Have air, have spark. Hell after we pushed it into my garage again I got it to start with starter fluid. Then it got a rough idle and died. WTF. Any help here would be great. Did the new pump already fail? Thanks for all the help.

Vader

Remove the line again and see if the pump moves fuel. If so, you may want to check your fuel filter in the carb. The new pump may have deposited some debris there. If not, you have some work to do.

An old trick is to remove the fuel tank cap, remove the fuel supply line to the pump, and blow compressed air back through the line. You should hear the air bubbling at the tank filler neck. If the pickup screen in the tank was clogged, it isn't any more. That doesn't mean it wouldn't clog again. This also won't work if you have an electric boost pump in the tank.

Sonix

iTrader: (1)

I was thinking:

where your hard line goes into the block mounted fuel pump (from your tank, your feed line), it should only be 1' long or so, and have a rubber line that goes to frame rail, where it's hard line again. Disconnect the rubber line that attaches to the hard line at the frame, this will be the fuel inlet to the block mounted fuel pump. Put that rubber line into a gas can, you can set it on the ground below your rad basically (bypassing the lines back to the tank, and a possibly dead electric fuel pump) and start the car. If it runs fine, you've solved the problem.
I would guess it's a dead electric fuel pump, that's blocking flow. Or clogged lines, either way this would bypass that, and tell you if that's the problem.

or a clogged carb fuel filter. You can replace that for $2 to be sure.

mw66nova

iTrader: (13)

i don't think that the 84's got the electric helper pump.

make sure you actually have fuel in the tank too.

five7kid

iTrader: (14)

They didn't routinely get the electric pump in the tank from the factory, but they could get it via a dealer-installed kit.

I'm still not clear if L69's got them, but my guess would be they are more likely to have it than LG4's.

mw66nova

iTrader: (13)

my suggestion:

follow the fuel lines up into the tank and look to see a wiring harness coming out of the back of the car, right in front of the fuel tank. if there is more than one wire, then there is a helper pump in the tank. drop the tank, take out the helper pump and attach a piece of 3/8" tubing via a brass compression fitting. this will get rid of the restriction.

i'm not sure why they put helper pumps in, my father and i are both running stock replacement $12 mechanical pumps for a 1985 305 z28. he's been 11.84@116mph, i've been 12.16@110mph, i don't think the factory pumps are the issue.

phess11

Helper pumps were put in to help with Hot Start vapor lock. Not for fuel volume.

five7kid

iTrader: (14)

Understood, but if the electric goes bad, you've got a good chance of having a volume problem.

Could still be the gunked-up pick-up sock that Vader was talking about. But, he needs to know for certain whether or not his car has the in-tank electric.

DocHoliday

Well somehow me and a buddy of mine got it running again. He says that the clamp on the fuel pump on the inlet line wasn't tight enough. It was loose enough to have a slight leak causing a drop in pressure. I personally think that the line had a clog in it. And when we floored it, it cleaned it out. Well it runs now. Thanks guys.

mw66nova

iTrader: (13)

vapor lock? i've never had a problem with that, and i drive mine everyday....of course my car doesn't have much other than just the motor under the hood anymore too.

five7kid

iTrader: (14)

Go get a $3 fuel filter then. If the line passed a clog, it's probably sitting in your filter causing a by-pass situation.
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Add AC, PS, a fuel line that goes up and over the transmission and behind the engine (where all the heat is going to go), stop & go driving on hot days - you'll get aquainted with Mr. V.L.

mw66nova

iTrader: (13)

nah, screw all that powder-puff stuff.

no ac and manual steering for me buddy!!!