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Old 03-14-2017, 10:33 PM   #1
Foxtrot
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The Worst! (Won't Start)

I swear, the truck only breaks down when my husband is driving it and then it's up to me to fix it.

Headed to work a few days ago, he was stopped at a light on an off-ramp for about ten minutes. When it was finally his turn to go, he pressed on the accelerator and the truck sputtered out like it was out of gas. Based on what he described to me, it was obviously a fuel flow problem so I swapped out the fuel pump and filter.

Still, the truck won't start. To prime, I poured some gas in the carb and it fires up for maybe a few revs (like normal from what I can tell), then stops. If I turn the ignition without adding anymore fuel, it makes a pop with each revolution like one cylinder might be firing, but if I put my foot on the accelerator this popping will stop and it just sounds like a truck trying to start without any fuel. Add more fuel to the carb, pop-pop-pop like it's starting, then back to a single pop with each rev until I touch the accelerator, then nothing but an engine turning over with no sign of combustion.
This is not what was happening after it died at the on ramp. There was no pop with each revolution.

When I removed the old fuel filter, I tore it open and found some very fine metal flakes. Also, when I was removing the filter and that line, I twisted the line a bit on accident (for some really stupid reason I tried removing the fuel line without having a wrench on the fuel filter as well, when I turned the fuel line's nut, it turned the fuel filter nut as well causing the fuel line to twist), but I twisted it back and while it my cause some restriction, it doesn't appear that it could be cutting off fuel altogether. Regardless of whether it's the issue, I'll be replacing it (pressurized and fatigued metal fuel line right at the top of the engine by the carb... just a fireball waiting to happen... if I can get the darn thing to run).

I tried priming again today, and it seemed like it was close to starting, but the battery wore out so I'm currently waiting for it to charge. Maybe there's nothing wrong currently, I just haven't primed it enough? I've poured a cumulative three cups or so of gas down the carb over a bit more than a dozen attempts to start.

At this point though, I'm assuming fuel is flowing fine (considering that pop with each rev). Pressing the pedal and causing that pop to stop confuses me though and makes me think there is maybe a fuel flow issue still.

I've also been thinking ignition issues (but it seems to run okay when I pour fuel in the carb) and timing issues, but I don't see how the timing could suddenly fail like that and I don't think it would cause the engine to sputter out like it ran out of fuel.

A coworker suggested that (considering the rain here in the Sound), water may have got in the distributor cap while I was working on it. That's the next thing I'm going to troubleshoot if my third attempt at getting it going doesn't when the battery is done charging. That'll be tomorrow though...

In the meantime, any suggestions? Anyone experience anything similar?

To summarize, was pretty certain the fuel pump had failed or the filter was clogged based on the description of how it died. Replaced said pump and filter. Tried starting with gas in the carb, fires up a bit then dies. When you turn the ignition, it sounds like it might be trying to fire at least one cylinder.
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Old 03-14-2017, 11:59 PM   #2
geezer#99
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Re: The Worst! (Won't Start)

Check your distributor isn't loose.
Then check your timing.
A slightly loose (hard to move but will move with some effort) distributor will rotate cw with the rotor motion and retard the timing.
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Old 03-15-2017, 12:14 AM   #3
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Re: The Worst! (Won't Start)

Are you getting fuel to the carb? I know there is a new pump and filter, but there. Hold be some sort of restriction in the line. If it starts when primed, then it sounds like fuel might not be making it up there.

What kind of engine and carb are you working on?
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Old 03-15-2017, 12:38 AM   #4
El Dorado Jim
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Re: The Worst! (Won't Start)

sub'd
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Old 03-15-2017, 01:18 AM   #5
Foxtrot
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Re: The Worst! (Won't Start)

Quote:
Originally Posted by geezer#99 View Post
Check your distributor isn't loose.
Then check your timing.
A slightly loose (hard to move but will move with some effort) distributor will rotate cw with the rotor motion and retard the timing.
I checked the distributor, but couldn't get any movement out of it. Wasn't applying too much force though.

However...

Quote:
Originally Posted by nonstop View Post
Are you getting fuel to the carb? I know there is a new pump and filter, but there. Hold be some sort of restriction in the line. If it starts when primed, then it sounds like fuel might not be making it up there.

What kind of engine and carb are you working on?

No fuel to the carb! This is actually kind of a relief. Removed the fuel line at the carb and no fuel was coming out of the line even after all the priming. To be certain, I laid on the ignition for ten solid seconds twice--no fuel squirts. Seriously, I feel really relieved right now even without having the truck repaired because this is a REALLY strong indication that the problem is still fuel-flow and that's a heck of a lot easier to fix (for me) than anything else except electrical issues.

Tomorrow I'll start working backward from there, but this basically limits it to just a few things:
- The new pump I purchased is faulty
- Fuel selector has a problem
- There is otherwise a blockage in the fuel lines
- Or I put the push rod in backwards? According to the (crappy) Hayne's manual (which I use as a quick reference in lieu of checking the full service manual I have in .pdf), when removing the push rod, I should be careful to install the push rod the right way. 1) the rod fell out when I removed the plug that keeps it in place so I have no idea which way it was in originally and 2) I'm pretty certain it's identical at both ends (no wheel or anything, just a straight, cylindrical rod).
- Or could I have used too much grease to keep the rod in place and this is fouling up the pump's ability to function?

The engine is a 454 MK4 (1979) with a Q-jet carb (Rochester M4M...E...?), all stock. Truck is a '79 C20 Camper Special--it has dual (independent) tanks.

Last edited by Foxtrot; 03-15-2017 at 01:32 AM.
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Old 03-15-2017, 01:33 AM   #6
Foxtrot
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Re: The Worst! (Won't Start)

Quote:
Originally Posted by geezer#99 View Post
Check your distributor isn't loose.
Then check your timing.
A slightly loose (hard to move but will move with some effort) distributor will rotate cw with the rotor motion and retard the timing.
...And I really do need to take a look at my timing. You actually replied to my first post in this forum months ago about the matter.

Thank you for being actively helpful!
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Old 03-15-2017, 07:04 AM   #7
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Re: The Worst! (Won't Start)

For fuel flow, check the rubber lines from the tank sender unit to the metal frame line(s) or selector valve(if dual tank). Also from selector valve to metal frame. If they are original(out of sight, out of mind), they are likely rotted to the point of letting air in and breaking the fuel pump's suction.

Your symptoms match my 75's when the valve to frame line hose started crumbling away a couple years ago.

When you prime the carb, you don't need very much gas. Think tablespoon instead of cups. If you are using cups of gas, could very well be creating a flooded condition.
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Old 03-16-2017, 02:03 AM   #8
El Dorado Jim
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Re: The Worst! (Won't Start)

Quote:
Originally Posted by Dead Parrot View Post
For fuel flow, check the rubber lines from the tank sender unit to the metal frame line(s) or selector valve(if dual tank). Also from selector valve to metal frame. If they are original(out of sight, out of mind), they are likely rotted to the point of letting air in and breaking the fuel pump's suction.

Your symptoms match my 75's when the valve to frame line hose started crumbling away a couple years ago.

When you prime the carb, you don't need very much gas. Think tablespoon instead of cups. If you are using cups of gas, could very well be creating a flooded condition.
x2 and I don't think there is a right or wrong way the rod goes into the engine to drive the pump, never heard of that...and too much grease wouldn't cause the pump not to work,it drives off the cam
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Old 03-16-2017, 11:41 PM   #9
Jstock85
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Re: The Worst! (Won't Start)

i had similar issues a few months back. I was getting fuel to the carb, filter was soaked with fuel when i swapped it thinking that was the problem. next i checked the lines for clogs thinking fuel shortage of some sort. air and spark were both good... Turned out to be the needle in the small brass bowl or whatever was sticking and not allowing fuel into the carb. taking the top of the carb off to get to it was a complete pain in the @$$!! i cleaned it up and put some 3-1 oil in it and dumped some marvel oil in the gas tank and its ran good ever since.
Hope this helps!
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Old 03-18-2017, 08:51 PM   #10
Foxtrot
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Re: The Worst! (Won't Start)

Quote:
Originally Posted by Dead Parrot View Post
For fuel flow, check the rubber lines from the tank sender unit to the metal frame line(s) or selector valve(if dual tank). Also from selector valve to metal frame. If they are original(out of sight, out of mind), they are likely rotted to the point of letting air in and breaking the fuel pump's suction.

Your symptoms match my 75's when the valve to frame line hose started crumbling away a couple years ago.

When you prime the carb, you don't need very much gas. Think tablespoon instead of cups. If you are using cups of gas, could very well be creating a flooded condition.
I meant I used a total of cups, but very little at a time.
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Old 03-18-2017, 08:54 PM   #11
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Re: The Worst! (Won't Start)

Problem solved!

And I really don't want to admit this, but technically it's that one of the tanks was out of gas.

The fuel selector isn't working properly so it selected the right tank and drained it. Put 1/2 gal in the right tank and it started right up.

The fuel selector sounds/feels like it's working, but obviously can't select the left tank.

I've read rapping on the metal portion of the selector or removing the lines and using cleaner can help free things up, but I may as well look at replacing it.

Unfortunately, I can't find a like replacement. There are universal replacements that I know will work, but I'd really like an exact. Even if I go to acdelco and search by my make and model, they offer me an all-plastic, multi-wire thing.

Where can I get a good old 6-port, single-wire fuel selector?
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Old 03-18-2017, 09:46 PM   #12
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Re: The Worst! (Won't Start)

So I've done some research. What I need is ACDelco Part 467513.



I found a post on here from a couple years ago that provided a wonderful link to this part on amazon, but amazon hasn't had that part since about then.

As people have said, this is really the holy grail of car parts for this truck. I've searched pretty thoroughly on the internet and can't find a reputable seller with this part. There are a few places to call (apparently there's a Dan's Auto Parts in Montana that had it at some point and a few others), but it's beginning to look like I'm not getting this part.

The common solution is to use ACDelco U7001.



This process requires all sorts of changes that I refuse to do like changing the switch and at least adding another wire to the selector. I refuse to do this. Also, I'm no engineer, but a motor-driven selector seems much more likely to fail and at upwards of $100 for a non OEM part, I don't think so.

On to plan C, if it'll work.

I've found a three-port, single-wire solenoid valve: Standard Motors FV1.



Since 2*3=6, can I just get two of these and simply daisy-chain the wire to both of them?

The only issues I foresee are either a) I don't understand the electrical side of this and the single wire won't be able to operate both solenoids or b) having independent valves is a safety issue--if one valve failed (especially the return valve), would it be possible for one tank to get pumped into the other tank and overflow? For reference, the fuel pump operates at 30GPH.
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Old 03-18-2017, 10:26 PM   #13
Foxtrot
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Re: The Worst! (Won't Start)

Basically, will this work?

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Old 03-19-2017, 07:55 PM   #14
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Re: The Worst! (Won't Start)

Before you buy anything, since the valve is making noise when you switch selections, you might swap the tank hoses just to make sure the left tank pickup isn't plugged or the left tank rubber hose doesn't have a hole in it.

From your description, sure sounds like the valve is stuck on right side but also sounds like replacing the valve is going to be a PITA, so might be worth the effort to make sure the valve is the problem.
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Old 03-20-2017, 06:38 PM   #15
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Re: The Worst! (Won't Start)

GMchinz on here sells them. I just bought one from him for my truck. Paid him $75 which included shipping. Good luck. Oh-and it was plug and play for my 87. No issues whatsoever.
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Old 03-20-2017, 06:38 PM   #16
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Re: The Worst! (Won't Start)

That was supposed to say GMachinz
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