It does sound like fuel, but please do the ignition test to prove it. Apparently you have time while it is cooling off, or whatever is happening since we don't know yet.

And, while you are testing try the accelerator pump test by looking down the carb and opening the throttle. The spurting fuel seems to indicate that you have either a blockage of fuel or are pulling in air at some point - which starves the pump for fuel if the air leak is upstream to the pump. But, if the accelerator test fails we know you don't have fuel in the bowl of the carb and if that is true the engine will not run.

Also, if the pump that is ahead of the valve is failing you may well have a problem with the valve. IIRC, the one you have is powered by the pressure from the in-tank pump, so if your pump ahead of the valve is failing then the valve may not have enough pressure to work properly. And, even if it has enough pressure it may be failing - I've seen more than one of them fail with good pressure. Again, I would bypass that thing in a heart-beat.

 

Ok, I will work on bypassing the switcher/hot fuel unit. Next, would you recommend removing the return line and regulator like others have suggested?

 

I had the original fuel system on my truck until I converted it to EFI recently. I had replaced the front pump right after I bought the truck, but the rear was still the original one. I really had no problems with it. I would check all the wiring unless you have already thrown in the towel on it. When the EVAP system was removed, are the lines capped or open? You do need a way for air to get in or out of the tanks.

 

No. I would make sure you are getting enough fuel into the carb by checking the accelerator pump when the engine stalls. And then I would check the ignition. If you don't have fuel in the carb when the engine has stalled then we'll chase that rabbit. But, if you do and the ignition isn't working then we'll chase that rabbit.

 

Ok, checked accelerator pump when it died. A couple of squirts and then dry!

 

Since it holds some fuel it looks like you squirted that out and the bowl is dry. So, Houston, you have a fuel problem. I'd bypass the valve next.

 

Ok, will do. Just as a thought though, I noticed that when it starts to spit and sputter, If I let off the gas, it will still run. If I put my foot into it and try to get it going, it will totally quit. Sometimes if I hold it in one place, it will surge going down the road, and continuously loose power and speed until it just can't go anymore, then it dies.

Also, I just checked the fuel flow by engine before and after 2nd pump.

Before 2nd pump fuel rate: slow but consistent.

After 2nd pump with 2nd pump on: faster fuel rate but with ALOT of air bubbles.

After 2nd pump with 2nd pump off: still slower rate as first try but with very little to no air bubbles.

Could it be the 2nd pump?

 

I think you have a leak between the 1st and 2nd pumps. And, that's where the fuel valve is - right? Bypass it and test again. If you have the plastic fuel lines the parts stores sell a splice kit that will serve to bypass it. You'll need both sizes - return and supply.

 

Ok, thank you. Yes, the switch valve is between the two pumps. Also, the is a combination of plastic and rubber house spiced throughout. I'm goin to run new house from front to back and bypass like you've said.

 

Here is the update: No Difference! Almost worst.

I have now bypassed the entire tank selector modual with brand new 3/8 line.

Now it acts like the timing is all wrong. Although the truck seamed ok on the timing, I decided to check it because of a small miss. It wasn't even close to the mark, but yet it relatively ran smooth, now that I put it art 8° btdc it lobes like a funny car with solid engine mounts! I tried outing it back and it dont change. Now it will spit and sputter right away, that is if it dont die.

Someone said to change the ICM (ignition control mod) as that had been known of heating up and failing....

What do you all think now?
Thanks for the help

 

Before yOu jump to ignition, do you have good fuel flow now?

 

My thoughs are your harmonic balancer has slipped, I'd move the timing back to where it was earlier (where it ran good). It'd probably be a good idea to verify TDC on your balancer to see if it has slipped or not.

Yes, the ignition modules will show symptoms like you're seeing - primarily no-start when hot - but we got on this fuel kick for some reason, I guess it looked like that.

Ignition modules can be tested at parts stores but I don't know how many stores have the equipment (hair-dryer-type thing) to heat the thing up to test for a heat-related failure.

My other thoughts are, if your changes didn't result in the problem going away, un-do your changes and put it back to the way it was (within reason). If you start changing a whole bunch of things, the chances of introducing new problems get higher.

I forget what year you have - is it computer-controlled? If so, did you disconnect the SPOUT connector when setting the timing?

 

Yes. Great fuel. everything is brand new up to 2nd pump. The only thing I did not change was the 2nd fuel pump and fuel regulator due to the erratic timing. The firing order acts like I switched all the plugs in the wrong places. I have now had 6 different people tell me that I've had 2 problems; fuel and the icm. The fuel is now done, so off to this. ..oh ya $375 lighter to!

And yes, I tested tdc; lines up perfect!

 

Ok, if by this you mean that you no longer have the bubbles in the fuel after the 2nd pump with it running then you've fixed one problem. Yes, you may have had two. Start on the ignition then, assuming you know you have plenty of gas in the carb - the accelerator pump shoots each time you hit it.

Trust me, there is light at the end of this tunnel. I've been lost in this tunnel many times before and I recognize some of the rocks.

 

Timber,

Nobody here can tell you what your problem is because nobody here has seen it and diagnosed it.

The only thing we can do is give you input on things to look for/at, it is still up to you to diagnose and repair it.