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 Post subject: Luv starts sometimes
PostPosted: Mon Sep 26, 2016 12:49 pm 
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Joined: Wed May 11, 2016 9:01 am
Posts: 54
Location: Lake Stevens, WA
Ok so I replaced my carb with a 32/36 weber. At the same time replaced, spark plugs, valve cover gasket, ignition coil, ballast resistor, alternator and battery (bad alternator killed my old battery).
It ran ok before with my old hitachi carb.
Installed a new weber with fuel pressure regulator set at 3psi, plugged up return line. And vented top of valve cover also plugged up any unused vacuum ports.

I had issues starting it but got it to run magically.
I let it idle for about 20-25 mins no issues, then tuned the fuel mixture and got my idle to set at 900 rpm.
I would turn it off and let it run again about about a couple of mins of running I hear it getting low on idle and it would die. I would start it back up and run fine then die. Then start it and it idled fine for about 10 mins so I turned it off.

So I let it cool for about a couple of hours then I adjusted the Fast Idle adjustment by having the truck off floored the pedal and released the pedal then started the truck and it went up to 2000-2500 rpm where I wanted it and it idled for about 5 mins and I shut it off. And called it a day

Next morning I tried to start it and won't start. I floored the pedal and released to get the fast idle but no luck would not start. I tried starting it for about 5-6 times and then left it alone.

Any ideas? Fuel pump looks to be original (80k+ miles). So maybe fuel pump? fuel filter? Condenser? Points? Voltage regulator? bad gas (2-3months old at 1/4 tank)?

thanks

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 Post subject: Re: Luv starts sometimes
PostPosted: Mon Sep 26, 2016 1:48 pm 
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Joined: Tue Oct 07, 2008 8:07 pm
Posts: 906
Location: N W Arkansas
Remove the fuel filler cap, see if it will then start & run.
If it will drill a small (1/8" or smaller) hole in the filler cap, at the top when installed is best.
If this works what has happened is this: during normal operation the fuel return line pressurizes the tank very slightly. With the return blocked off a vacuum is created in the tank as the engine runs, the more fuel burned the greater the vacuum & the harder it is for the fuel pump to pull fuel from the tank. As it sits for a while the vacuum will bleed off.
If this doesn't work then start from scratch, test for spark at the plugs & fuel at the carb, if you have both it should start, if not trace the pathway of the missing component until you find the stoppage.
Some things to remember: No start & poor running can be two separate problems; New parts are sometimes bad; Everyone makes mistakes sooner or later, go back over the install again, make sure everything is installed properly.

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'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.


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 Post subject: Re: Luv starts sometimes
PostPosted: Mon Sep 26, 2016 5:09 pm 
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Joined: Wed Feb 22, 2012 10:47 am
Posts: 313
Location: Los Angeles, CA
Barring fuel flow issues like those mentioned above – and perhaps this is a stupid suggestion – maybe try wiggling the carb around next time it dies like that?

You may find a teensy bit of play when it gets hot that isn't evident when the engine is cold. I had this issue in the weeks after a Hitachi replacement right when I got the truck, and again after the Weber upgrade, done by separate mechanics. I thought the first mechanic was just doing a CYA maneuver until it happened again...

I have to admit, the fastener choice seems strange - a headless standard-threaded bolt. It wouldn't be an issue with a normal bolt, but a headless one comes loose from two places instead of one so functionally it acts more like a bolt with half of the already-low thread count it has! It seems obvious this would happen. A fine-threaded option seems like it would have been a no-brainer...In a vibrating environment like the top of an old 4-banger, it. Over time, without a mild thread locker, I feel like the stock carb mount is bound to shake loose.

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 Post subject: Re: Luv starts sometimes
PostPosted: Mon Sep 26, 2016 7:11 pm 
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Joined: Wed May 11, 2016 9:01 am
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Location: Lake Stevens, WA
OK I did remove the gas cap after a few tries it started with giving the gas pedal to the floor then releasing and the RPMs were about 2k at idle until I touched them pedal again after a few minutes have past.
I let it idle for a few more minutes and gave it a few revs, all seems good until I have it a bit more revs basically giving it some wide open throttle at idle then it would die.
It feels like it was either losing gas or getting choked.
I am leaning towards getting a new fuel pump soon and swap it out.
What you guys think?

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 Post subject: Re: Luv starts sometimes
PostPosted: Tue Sep 27, 2016 1:09 am 
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viewtopic.php?f=5&t=30073

Recent fuel pump thread

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 Post subject: Re: Luv starts sometimes
PostPosted: Mon Jan 30, 2017 1:24 pm 
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Joined: Wed May 11, 2016 9:01 am
Posts: 54
Location: Lake Stevens, WA
During December I replaced fuel pump, fuel filter, Condensers, Points, Voltage regulator, alternator.
So got it running to where I can drive it but slow, due to fuel cutting out at more then partial throttle.

I can start it and idle fine and drive it, but once I floor it it cuts out or stalls either its not getting gas or its flooding it. If it starts cutting out I back out of the throttle to partial then its going again.
Its hard to get up to speed at partial throttle especially this is already slow truck at stock range.

Anyone have any ideas on why it is cutting out at above partial to full throttle?

thanks

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 Post subject: Re: Luv starts sometimes
PostPosted: Mon Jan 30, 2017 2:26 pm 
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Joined: Fri Sep 20, 2002 12:49 am
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Location: North Mississippi
Sounds like fuel delivery. Clogged fuel filter perhaps.


The tank and supply line may also be rusted up. If that's the case you can take it to a radiator shop and have it cleaned and lined.


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