Truck left me stranded today.

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AuroraGirl

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These have 3-4k miles on them


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Heres a low mileage and low hour set from my truck , but in its defense it runs much better now but it doesnt see the road so not fair on plugs lol
 

sgrinavi

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did you get antiseize on the strap on pulling it out? (joke there haha so funny) Also these are taper plugs, but it looks like the tapers might be cruddy unless that iis just light and antiseize in the photo
Are those AC delco plugs low mileage or they old? I know you can still buy the old stock kind like those and they look the same I believe still, so I dont want to judge it by looks
lol. Low mileage plugs. Which part is cruddy?
 

sgrinavi

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If it has an hei dizzy, if the ignition module is bad most of the time it will work fine until things heat up, check the ignition module for sure

I replaced the cap, rotor and module last week. The wires were replaced when I did the plugs
 

AuroraGirl

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lol. Low mileage plugs. Which part is cruddy?
The part where the taper is, at least it looked like it. its where it seals to the head. if thats rusty or has any debris, you can get unsealed chambers
 

sgrinavi

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The part where the taper is, at least it looked like it. its where it seals to the head. if thats rusty or has any debris, you can get unsealed chambers

This is the part that has me concerned. Seems like too much build up for low mileage plugs

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AuroraGirl

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This is the part that has me concerned. Seems like too much build up for low mileage plugs

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can you see carbon if you look in the cylinder opening?
 

Grit dog

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This is the part that has me concerned. Seems like too much build up for low mileage plugs

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Do you ever run the engine hard? The old “blow the carbon out” moniker still applies.
Aside from your fuel pump lobe issue, if it’s an old motor that has done more putzing around and sitting than driving hard and towing, that could explain the little deposits.
But they’re not oil fouled so no real issue.
 

DoubleDingo

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Do you ever run the engine hard? The old “blow the carbon out” moniker still applies.
Aside from your fuel pump lobe issue, if it’s an old motor that has done more putzing around and sitting than driving hard and towing, that could explain the little deposits.
But they’re not oil fouled so no real issue.
^^ This ^^
 

sgrinavi

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can you see carbon if you look in the cylinder opening?
Yeah, on top of the piston

Do you ever run the engine hard? The old “blow the carbon out” moniker still applies.
Aside from your fuel pump lobe issue, if it’s an old motor that has done more putzing around and sitting than driving hard and towing, that could explain the little deposits.
But they’re not oil fouled so no real issue.

I get her up to 4k RPM for a few seconds, a few times, just about every day... how hard is hard?
 

Grit dog

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Yeah, on top of the piston



I get her up to 4k RPM for a few seconds, a few times, just about every day... how hard is hard?
Idk. But could explain the crustys on the plugs
 

AuroraGirl

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Yeah, on top of the piston



I get her up to 4k RPM for a few seconds, a few times, just about every day... how hard is hard?
what heat range is your plug? based on that im convinced you would benefit from revs under load (uphill on ramps to freeways are great for this)
And tho expensive for the GM product, seafoam makes a apply, soak, then run treatment that can help clean up that.

realistically, this can only do so much. you have coked up combustion chambers, which increase compression, increase likelihood of detonation(hot spots) and also contribute to rough running. If its not a lot to much for you, you could pull the heads and then clean it up with walnut material like ive seen on yt lol
 

Grit dog

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If it has an hei dizzy, if the ignition module is bad most of the time it will work fine until things heat up, check the ignition module for sure
True story although maybe @sgrinavi verified it’s getting fuel starved? (Without reading back thru the posts)
Also @sgrinavi I believe a return line would help considerably as the electric pump won’t be partially dead heading under normal light load conditions. Was the pump getting real hot when it died?
Interested to hear how you like the new pump.
I’m still running a cheapo Edelbrock in line pump which seems to be surviving well now that I relocated it down by the fuel tanks and give it good clean power.
Planning on replacing with a better quality pump and external regulator for reliability.
(No mechanical pump option on my engine. It’s a 90s Vortec efi long block.)
 

sgrinavi

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True story although maybe @sgrinavi verified it’s getting fuel starved? (Without reading back thru the posts)
Also @sgrinavi I believe a return line would help considerably as the electric pump won’t be partially dead heading under normal light load conditions. Was the pump getting real hot when it died?
Interested to hear how you like the new pump.
I’m still running a cheapo Edelbrock in line pump which seems to be surviving well now that I relocated it down by the fuel tanks and give it good clean power.
Planning on replacing with a better quality pump and external regulator for reliability.
(No mechanical pump option on my engine. It’s a 90s Vortec efi long block.)

Fuel starved, but only after it heats up and not always. I believe that it's vapor locking. When I'm fussing with it on the side of the road and remove the fuel line from the carb any fuel that drips on the intake is instantly boiled away with a sizzle. Cooling system is in good order, I think, since while the fans are running and the AC is off it stays under 180/185. I supposed the water pump could be suspect, but I have my doubts.

The pump is under the rock shield next to the switching valve, hard to say. I have not melted any wires or fuses though.

I'm going to install a pressure regulator with a return this weekend and I have a new carb on the way with a phenolic spacer that should be here in the next couple of weeks.

what heat range is your plug? based on that im convinced you would benefit from revs under load (uphill on ramps to freeways are great for this)
And tho expensive for the GM product, seafoam makes a apply, soak, then run treatment that can help clean up that.

realistically, this can only do so much. you have coked up combustion chambers, which increase compression, increase likelihood of detonation(hot spots) and also contribute to rough running. If its not a lot to much for you, you could pull the heads and then clean it up with walnut material like ive seen on yt lol

Plugs are ACDelco R44TS. Are you referring to the SeaFoam spray? I've used it, lots of smoke lol. Taking the heads off a 160k mile motor doesn't make a lot of sense fpr me, I would replace the motor first. I will at some point, but I just can't bring myself to throwing something that works, most of the time, away. I have another car, not like I really need this to be 100%

Idk. But could explain the crustys on the plugs

Okay, I'll run it a little harder. What could go wrong?
 

Grit dog

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Haha not suggesting you blow it up! Idk how solid of a motor it is.
it doesn’t look fouled out or running rich.
I’d just fix your fuel issue and keep running it. Throw a heavy duty fuel pump and a regulator on it and a return line and it should run forever.
A little carbon in the motor is not gonna hurt anything. And not the cause of it dying.
Good luck
 

boltbrain

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Those filters are not high quality, get yourself a metal wix (Im sad wix is selling that kind..)
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This product people have said is decent when using both SBC and electric pump, as it will allow flow-through when off. which means you could have it on a toggle at the very least to check the theory about vapor lock concerns.All fuel hose clamps should be replaced with fuel injection clamps if you have cheap worm ones them up by the fuel pump, air can sneak by and then throw wrench into your issue.

as to the question of where to place an electric frame pump, if you had one tank I would say below the level of fuel if all possibly and a model without a check valve as close to the tank.
If you have 2 tanks, a check valve pump can be placed further away and below fuel level if possible, but im not sure how it would interact with tank switching valve. I believe ford in the late 80s used the same one as the late 80s GM, but they had their pump before but I could be mistaken
Isn’t it possible to find an electric pump that can pull sufficient fuel high enough and far enough to service both tanks in a safe convenient location reliably regardless?
 

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