68 f100 390 FRUSTRATING COLD START

[mkonecek]

well.....I appreciate all of the responses. im more frustrated than before.
I was suspecting rust in the tank. installed a 10 micro filter. during install, I blew the inline filter that was installed and got a ton of fine rust (or something else)
Now that the filter is installed, I figured we are good until we hot tank the fuel tank.
wrong. Even though I put 10 miles or so on it, the kid stalled at a light. replaced the pump with one from under the seat (keeping extras now)
and drove it home. next morning, no start. and that's where I am at!
He removed the filter from the equation and it still will not start.

I ordered new fuel line, new filter, and a new fuel cap. Sending the tank out tomorrow.

Im having a hard time believing the pump failed with a 10 micro filter in front of it. Nothing can get through and its still 90gph.

Could be the cap but should start after the tank pressure is relieved if that is the case.

kid says when he was cranking, the aftermarket tach started going backwards.

I get that the fuel pumps are not pumping but maybe a coil?

Also, do these mechanical pumps really fail with a little debris in them??? can't believe that.

first pump lasted 2 months. now they last less than 20 miles.

maybe not a pump. although I do not see fuel coming out, im wondering if maybe I am chasing the wrong issue.

[briansbronco]

Here's what I would do. Take the fuel tank out of the equation. Draft fuel from a gas can. Length of hose from the fuel pump should be sufficient to establish a good, clean fuel source. Then check everything out based on the clean fuel source. If it's still not cranking or running look at the usual suspects.

[basketcase0302]

From my earlier post:
"do you see a stream of gas with the engine off looking into the carb throat when you open the gas?"
Still need to verify the stream of fuel when it stalls to rule out fuel pump issues/ gas cap issues / debris in the fuel issues.
Brian's got another good tip above by letting the gas siphon from a can sitting on the bed rail of the truck, (up higher) down to the fuel pump.

But...
And your post after that:
While driving and warmed up already, it will starve

Is telling me you might have a coil issue, (also a sign with the tach spinning backwards).

Can you have a plug wrench on hand and pop #1 plug / ground it / try cranking the next time it happens. And be prepared for a loud engine if it decides to start while you have the plug out-just shut it down quickly no damage done.
I'd buy a good replacement, (not autozone / big box parts stores brands) coil and throw it on the truck at this point as I know how dangerous the stalling issue can be in traffic of in a metro setting.
This is also where you really need a remote starter button, (been there done that running back and forth from engine bay to ignition) that will save you precious time and energy. they're cheap enough and i always carried one with me for ease of troubleshooting, (you can get it at any autozone or big box parts stores):
https://www.ebay.com/itm/12V-Push-Butto ... SwRXRZUbLp