Won't crank after installing new fuel sending unit.

[Mels72C20]

Okay guys, I finally got the correct fuel sending unit for my truck and popped it in. Key on, 1/2 a tank, yeah it works. Then I proceeded to change the tranny fluid, new pan, gasket, and dipstick to fix the really bad leak I had. Filled it to just below the add mark and went to crank it up to start getting the level right. Truck fired up momentarily and cut off. Now it won't crank at all. First of all, I am carburetor stupid! Any help on what to check would be appreciated. Truck has a 350 with the original Rochester quadrajet.

[BigDaddyV]

Good old Quadraflood. Give it a bit and try it again. possibly just flooded it, My truck has been doing the samething but I need a carb rebuild and new fuel tank... Dont get discouraged, Lots a good peeps here that will help out.

[Lee H]

Originally Posted by Mels72C20

Now it won't crank at all.

Meaning the starter will not turn over the engine or the starter turns over the engine but it will not fire?
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[Mels72C20]

I thought it may have been flooded. I had to leave it sitting for work and I tried again two days later to crank it with no luck. It turns over, but either it something with fuel or maybe no spark. When I operate the throttle by hand I see fuel spraying into it. I fixing to go out to the shop and I was just wanting to get some ideas before I started.

[PanelDeland]

Try priming it.Even though you're getting some squirt,you have gotten air in the fuel lines while they were apart to install on the new sending unit.

[Shyguy]

If it is not flooded, starting fluid should allow it to start if it is a fuel delivery problem. If it does not start with starting fluid you will have to see if there is a spark at the plugs.

A wise member of this board, not me of course, has said often what is needed for an engine to run is: air, fuel and a spark if memory serves right. That is what is so good about this board we have so many knowledgeable people that are always willing to help. I have learned a lot from them.

[Mels72C20]

I have some starting fluid on hand. How much should I spray in there? I think it air in the line as well.

[Shyguy]

Take the air cleaner off and spray in the throat of the carb, one good squirt. It may not stay running the first time if you have air in the line. Sometimes I have to try 3 times.

See if it starts the first time, like I said it will tell if you have a fuel delivery problem or lack of spark.

[MikeyMan]

Originally Posted by Mels72C20

It turns over, but either it something with fuel or maybe no spark. When I operate the throttle by hand I see fuel spraying into it.

I've had issues with flooding on my 307 2bbl Rochester. Once that thing dumps some fuel, I can't get it to fire. More cranking only seems to suck down more fuel. The plugs get wet and don't want to fire.

What I ended up doing was pulling each spark plug and drying them with the air compressor. A little blast of air into the cylinder too. Once they're dry, I can get it to fire. Wet spark plugs in the sealed combustion chamber ain't gonna dry up anytime soon.

Of course, you need to check your ignition system and make sure you are getting spark to the cylinders. Also, check your engine oil to see if any gasoline may have leaked down.

[luvbowties]

Originally Posted by Mels72C20

Okay guys, I finally got the correct fuel sending unit for my truck and popped it in. Key on, 1/2 a tank, yeah it works. Then I proceeded to change the tranny fluid, new pan, gasket, and dipstick to fix the really bad leak I had. Filled it to just below the add mark and went to crank it up to start getting the level right. Truck fired up momentarily and cut off. Now it won't crank at all. First of all, I am carburetor stupid! Any help on what to check would be appreciated. Truck has a 350 with the original Rochester quadrajet.

It is super easy, when replacing the dipstick, to pull a wire off the coil or the distributor. Since u see fuel spraying into carb when pulling the throttle back, sounds like you're missing spark; u might ought to look for that loose wire. HTH,
Sam