Dodge Van wont start

1986 Dodge Ram 350 van. Van was running perfect.

I just replaced the fuel filter and all the rubber lines. 

Cant get the van to start now, I may have flooded it, I'm not terribly gifted with carbs. Very first time I tried to start it after replacing the filter it sputtered on but then died a moment later and I've not been able to start it since. The solution every other time I've flooded, is to hold the pedal to the floor while cranking, which i think opens the choke completely? Anyways that's what they tell ya in the owner's manual and it's always worked. It is not working now and anything I've tried has resulted in endless cranking.

So, tired of messing around, I took the hump off, opened the air cleaner and got some starting fluid to spray directly into the carb. Because surely if I could just get it to fire for a bit, it would get that mechanical fuel pump working, fill the lines and everything would be back to normal right? Well I'm pretty sure I'm doing something wrong because it still wont fire even with the starting fluid.

Here's my carb, hopefully someone who knows this old American stuff can tell me what I'm doing wrong. Is there a secondary choke stopping the starting fluid or something? I've opened every valve visible and gave it some starting fluid and got nothing. This seems like a pretty simple problem, what am I missing?

Fuel filters generally only flow in one direction, did you put it in backwards? Sounds like you are not getting any fuel

06HHR (Forum Supporter) said:

Fuel filters generally only flow in one direction, did you put it in backwards? Sounds like you are not getting any fuel

My first thought too. Then try start fluid, 1 spray should be enough. Which engine?

Pull a spark plug to see whether you're dealing with flooding or no fuel?

The lack of trying to start with starting fluid suggests "too much" is a possibility. OTOH, stumbling on the first try sounds a little like it tried to run on what was left in the carb.

Just to be clear, because I feel like there was some ambiguity in the exposition, "flooding" so much fuel you can't light it, and holding the throttle wide open lets lots of air in without drawing in much or any fuel.

Check for fuel where the line enters the carb?

Did this project involve the van sitting for very long after last run? Just wondering about a sticking float valve.

Any possibility that hoses got switched and you are pumping fuel into the vapor line?

The butterflies over the secondaries are an air door.  The throttle linkage is mechanical, but those doors open only when airflow is demanded, so it is kind of like having vacuum secondaries.  Since they also raise and lower fuel metering rods, it is also kind of like an SU carb back there.  Neat setup when it works right, and it usually does if it hasn't been screwed with too much.

You have either created an air leak on the suction side of the fuel pump, and getting no fuel, or you have dislodged a chunk of something and stuck the float valve open, and it's flooded.  

Hold the primary (small) choke plate open and work the throttle.  You should see a fine stream of fuel coming from the accelerator pump nozzles.  If not, you have no fuel.

If the float valve is stuck open and flooding, then should be fuel drooling from someplace in the carb body.

Or, you accidentally unplugged something important to the ignition.  Unplug the coil wire from the distributor and grab on the end of it while cranking the engine.  Not really, although you will know if it has spark that way.  Hold the coil wire close to something steel and crank.  Spark, you didn't unplug anything too important.

In reply to Streetwiseguy :

Alright so after some finnicking it does start on starting fluid. So it does have spark, air, everything. But you're right I'm not getting fuel. But my question remains why the heck not?! Van ran perfect, then I swapped out the rubber lines and filter, and now no run. Nothing else changed. And on the topic of that filter here it is:

I've marked all the lines for clarity. I'm 99% sure everything is plumbed correctly. In the top right you can see the pump. Green line comes from the tank and goes into the pump, red line comes out of pump and goes to the filter. On that bottom side where that line goes in there is inscribed "IN" and an arrow on the side of the filter. So the filter is the right way up, I replaced the green line separately before the others so that I wouldn't mix it up, only place for the red to go is the bottom of the filter and then the blue return line is a smaller diameter than the rest, so you can't mix that one up. Had to give this a run down to make sure I'm not crazy.

So assuming everyone agrees that's right, what else is going on here, why am I not getting fuel? It ran with that pump 5 days ago

With fire extingisher at hand, pull the hose off the pump and see if it is still pumping.  Point the hose somewhere safe.  Disconnect the coil,etc.   Then turn over engine.

Then put it back together and do the same thing by pulling the hose off the exit side of the filter.

If it pumps.  You have to pull the new lines off and check for blockage.

If all that passes.  It gets harder, because you may have pumped trash into the carb.

put the old E36 M3 back on and see if it runs

Squeeze the return line off with vice grips and give it a go.  

In reply to Purple Frog (Forum Supporter) :

Alright well all lines before and after the pump and the filter were flush with fuel, so I supposed it's time to take apart my carb...

Don't these have a small filter at the inlet of the Rochester carb? The line is a 5/8 nut and the filter holder is 7/8 or 1 inch?

Assuming you have spark, you should definitely see if it pumps fuel to the carb. On my old 318 in my truck, I had two fuel pumps fail due to junk in the tank clogging them up. The sending unit sock disintegrated into bits that would clog everything up. Also, since that's a Quadrajet (at least it appears to be), they should have a small filter at the inlet. Change that out, too. 

Another thing if all that seems good: check timing. The LA engines are notorious for timing chain issues and stretching, and on my old 318, it got so loose that it popped off, which created a no-start condition (and bent a bunch of pushrods and caused a valve and cylinder to get cozy). Hope it's not that, especially on a van. 

Here's the deal with older mechanical diaphragm pumps.  As the diaphragm ages, it becomes stiff.  It will run seemingly forever, but as soon as the fuel drains out of that pump (like when you're changing lines) it dries out and cracks and dies.  It's very common when you're doing fuel line work for an old pump to be instantly useless once you get it back together.

Pull the line at the carb and point it into a cup.  Have someone crank and see if you get fuel.  If you don't, pull the line off the filter inlet and see if you get fuel the same way.  I suppose it's possible the filter is faulty, but not much to fail in there.

If you get fuel just fine, obviously check the spark.

You're on the right track with holding the throttle open when it's flooded.  That gives it big gulps of air.  Often times with carburetors if you flood the engine, it just takes a while of cranking at WOT to get it to fire.  Another option (if you don't want to do the WOT which risks making it worse first with the pump squirt), is to just stick a screwdriver in the secondary doors and the choke to hold them open while cranking.  If the plugs are soaked, they are giving a weak spark as well.  I'm sure it's not easy in a van, but you can take the plugs out and hit them with a propane torch to burn off the gas, dry them out, and preheat them.  Even if you can only reach three, that will help.

Your carb is most likely a Thermoquad, yes?  It's basically a Rochester Qjet with a composite bowl assembly to prevent heat soak.  They're great carbs, but as someone mentioned, they do have a filter behind the fuel inlet.  Spin that puppy out and check it.  If you have a good enough filter inline, you can skip it, but they're $3 and don't restrict fuel except in demanding applications (like 400+ hp), so it can't hurt to replace it.  There are two types; a papery one and a sintered bronze filter.  The sintered bronze is better at filtering, but easily clogs and you can't really see when it's obstructed.

How much starting fluid are you using?  A couple short blasts won't do it.  Spray and count to three, then put the air cleaner cover back on in case you get a wee backfire.