Stranded… could use some ideas.

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78C10BigTen

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on a lot of Chevrolet engines if you look down at the passenger side front of the block next to the timing cover, there is a bolt (two bolt holes on top of each other, early motor mount locations) that lines up with the location of the fuel pump push rod in the block but it is a short bolt for normal operation to keep interference from happening. If you remove the fuel pump and push your finger against the fuel pump push rod, have someone bump the engine over until you feel its all the way bottomed out against the base of the pump drive cam lobe, remove the above mentioned bolt, install a longer one until it is snug (basically finger tight) so it holds the pump push rod, install your new gasket and fuel pump then remove the longer bolt and install the original bolt back in it's location and that's how you change a fuel pump on Chevrolet engines without headache. Grease is a good trick too, and usually the much faster method! because not all blocks had the provision, but the above is the proper way and most people don't know that little nugget of installation information even exists.
After many fuel pump changes i finally learned this trick! Lol i felt like such a *******
 

Raider L

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@7900_Blazer,

In anticipation of problems like the ones you're having, when I was rebuilding my truck and the engine was out of the bay, I had some aircraft grade heat wrap, and I had a spool of safety wire so I looked at how far away I would need to go before and after where the fuel line was near the header tubes that were close to the fuel line at the frame and wrapped all the fuel line and attached safety wire around it at points to make sure it would never come loose.
Then on recommendations from some of my racing friends they said to put a lifter valley cover in the motor. What that does is keep hot oil from splashing up on the underside of the intake keeping the fuel charge cool.
Then I put a 1/2" phenolic spacer under the carb to keep the carb from picking up heat off the intake further cooling the fuel.
Then I actually measured where the fan was inside the radiator shroud to make sure it was where it was supposed to be in order to draw all the air it could. You can by any size of spacer from Summit to get the proper spacing of your fan. I kept the factory six blade, I think, metal fan so it would not flex under load and pull all the air it needed.

I would ask if you would check to see if your fan shroud was all around the radiator, and that whatever fan you are using is the kind that is supposed to be on your engine, because I don't care where you live 210-215 is not anywhere near normal even for hot climates, even modern injected engines don't run that hot. The Max normal operating temp of the Chevy engine is between 190 and 200....period. 180 is where the thermostat begins to open.
Check your shroud.
Check your fan spacing.
Check your thermostat and put a 180 in there. Running between 180 and 190 even on a hot day in the middle of Summer in Louisiana is normal, maybe 195 is okay. But anywhere over 200 means something is off somewhere. I know a lot of guys have 454's and their temp is probably 200 to 205 in the Summer and for a big motor that may be fine but even then not no 210- 215.

When I got my new welded Aluminum 3 core radiator I thought something was wrong with it because it seemed to be running to cold, and even asked for help on this forum. But I read the info that came with it and found it is supposed to run 20 to 30 percent cooler than a brass, copper radiator like I had, and was used to seeing the temps it would be.

Maybe you can look into getting one of the welded Aluminum radiators for even further cooling of your water. And that would keep the engine cooler than you are presently running and that in turn would keep the fuel pump and other fuel parts cool as well, especially fuel lines, the frame, and even the engine compartment cooler. All this is good insurance towards preventing the hell you just went through.

I believe your engine temps is the second problem you've got with possibly causing some of your fuiel problems. Get that temp down!!
 

Raider L

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@Bextreme04,

My gas cap is vented. Do you reckon part of the problem was because he doesn't have a vented gas cap? Wouldn't that be a hell of a note, that all this time it was the gas cap?? My wife's Subaru had a problem like this one time and it turned out she needed a new gas cap, something had happened to the old one and it wasn't working right. A new cap solved the problem. It was coughing and stumbling and all these lights were on in the dash and all it was, was a gas cap.
 

Raider L

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@Bextreme04,

My gas cap is vented. Do you reckon part of the problem was because he doesn't have a vented gas cap? Wouldn't that be a hell of a note, that all this time it was the gas cap?? My wife's Subaru had a problem like this one time and it turned out she needed a new gas cap, something had happened to the old one and it wasn't working right. A new cap solved the problem. It was coughing and stumbling and all these lights were on in the dash and all it was, was a gas cap.
 

7900_Blazer

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@7900_Blazer,

In anticipation of problems like the ones you're having, when I was rebuilding my truck and the engine was out of the bay, I had some aircraft grade heat wrap, and I had a spool of safety wire so I looked at how far away I would need to go before and after where the fuel line was near the header tubes that were close to the fuel line at the frame and wrapped all the fuel line and attached safety wire around it at points to make sure it would never come loose.
Then on recommendations from some of my racing friends they said to put a lifter valley cover in the motor. What that does is keep hot oil from splashing up on the underside of the intake keeping the fuel charge cool.
Then I put a 1/2" phenolic spacer under the carb to keep the carb from picking up heat off the intake further cooling the fuel.
Then I actually measured where the fan was inside the radiator shroud to make sure it was where it was supposed to be in order to draw all the air it could. You can by any size of spacer from Summit to get the proper spacing of your fan. I kept the factory six blade, I think, metal fan so it would not flex under load and pull all the air it needed.

I would ask if you would check to see if your fan shroud was all around the radiator, and that whatever fan you are using is the kind that is supposed to be on your engine, because I don't care where you live 210-215 is not anywhere near normal even for hot climates, even modern injected engines don't run that hot. The Max normal operating temp of the Chevy engine is between 190 and 200....period. 180 is where the thermostat begins to open.
Check your shroud.
Check your fan spacing.
Check your thermostat and put a 180 in there. Running between 180 and 190 even on a hot day in the middle of Summer in Louisiana is normal, maybe 195 is okay. But anywhere over 200 means something is off somewhere. I know a lot of guys have 454's and their temp is probably 200 to 205 in the Summer and for a big motor that may be fine but even then not no 210- 215.

When I got my new welded Aluminum 3 core radiator I thought something was wrong with it because it seemed to be running to cold, and even asked for help on this forum. But I read the info that came with it and found it is supposed to run 20 to 30 percent cooler than a brass, copper radiator like I had, and was used to seeing the temps it would be.

Maybe you can look into getting one of the welded Aluminum radiators for even further cooling of your water. And that would keep the engine cooler than you are presently running and that in turn would keep the fuel pump and other fuel parts cool as well, especially fuel lines, the frame, and even the engine compartment cooler. All this is good insurance towards preventing the hell you just went through.

I believe your engine temps is the second problem you've got with possibly causing some of your fuiel problems. Get that temp down!!

Thank you for the feedback. The reality is I know very little, but learn a ton from everyone on this forum… my wife’s Yukon always runs at 210… and has 373k… but I’d very much like to see my 350 run at 190 or so…

As I’ve mentioned above, I’m confident much of my problems were heat/vapor related so getting a 180 degree thermostat and maybe a better radiator will be a priority.
 

80BrownK10

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I few questions/thoughts from this experience:

- At operating temp, my engine coolant is roughly 210 degrees... won't gas with ethanol simple turn to vapor at that temp - requiring moving from a mechanical pump to an electric pump?

- I'm NOT excited about relying on an Edelbrock electric fuel pump: one with many reviewers having experienced their lack of build quality/reliability - are there better 'carbureted' electronic fuel pumps you all use?

- I was convinced the pop-tart wrapper was the problem... but learned differently when my Blazer got up to operating temperature (and I was again on the side of the road)

- Am I left with the fact that all 'modern' (ethanol) fuel has a lower boiling point (turning from liquid to vapor), so having a pump NOT bolted to the side of the motor is the new normal?

- Is there a realistic option to get the operating temperature of my motor down to say 180, and with minimal pressure, never see a vapor lock issue?

- I don't understand why I've never had this happen in Texas...

- I don't understand why in Colorado Springs, running off the gas can in the floorboard got me going again...

- If you say 'the gas coming from the gas can in the floorboard was cooler than the pre-heated gas running through the factory lines down the frame'.. my response would be: 'then why did it still vapor lock when I ran a new rubber line outside the frame rail away from the heat? - I would add that the mechanical fuel pump was the same temperature as the block... so any fuel entering it would turn to vapor..

- My wife's GMC Yukon has 360k... and she'd driving it around the mountains like it's brand new... I've tried to upgrade it for her but she won't budge until she hits 400k.... never touched the electronic fuel pump inside the tank... so how do I replicate that reliability? - Go to EFI?

-To say the least, I'm pretty bummed about the future prospects of just running an old stock Chevy...
I wouldn't say EFI is the only answer. When these things were new and even 20 years ago it was basically just as Hot as it is now in the summer. These trucks when new were workhorses more so than today. Pulling trailer loaded with all kinds of stuff, backs loaded with wood to go to a construction site, tools for someone's job, sand for brick masons etc. I wasn't alive untill the early 80s but I don't remember these things stranded all over the side of the road in the summer time vapor locked on the slightest hill.

For one I would get your radiator rodded out and or check your timing. I think your running a little too hot to be empty even at 95 or 100f outside. This I don't believe is your only problem though. Maybe add 9ne of those filters that has a bypass in it as well to keep more fuel flowing if you do not have a return line. If you install one you will need the 3 line pump as well. I would get rid of the electric pump and put a mechanical one back on. If this means running off a 6 gallon boat tank untill you figure it all out that's what I would do.
 

80BrownK10

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Ah, of course, great trick.
There is also a bolt there on the front that they say you pull it out and can put a longer bolt into it and that holds the rod up while you bolt the pump on. Then you remove that bolt and put the small factory one back in .
 

7900_Blazer

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I wouldn't say EFI is the only answer. When these things were new and even 20 years ago it was basically just as Hot as it is now in the summer. These trucks when new were workhorses more so than today. Pulling trailer loaded with all kinds of stuff, backs loaded with wood to go to a construction site, tools for someone's job, sand for brick masons etc. I wasn't alive untill the early 80s but I don't remember these things stranded all over the side of the road in the summer time vapor locked on the slightest hill.

For one I would get your radiator rodded out and or check your timing. I think your running a little too hot to be empty even at 95 or 100f outside. This I don't believe is your only problem though. Maybe add 9ne of those filters that has a bypass in it as well to keep more fuel flowing if you do not have a return line. If you install one you will need the 3 line pump as well. I would get rid of the electric pump and put a mechanical one back on. If this means running off a 6 gallon boat tank untill you figure it all out that's what I would do.

I agree completely, it typically runs at over 200,but can go up a bit depending on RPM and load. If I keep it under 2250 rpm, it stays under 200, if I push it higher to say 2500 RPM, it will sit at about 210…
 

7900_Blazer

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So another update.

As I mentioned above, I installed an Edelbrock electric fuel pump back on the frame by the tank, in the parking lot of an Oreilly’s in Colorado Springs.
It got me through the mountain passes and back home to Texas (12 hours) without issue.

I have two goals:
- Bring the engine temps down a bit to 180 or190 degrees when running at 2500 RPM (my cruise RPM).
- Install a 3 port mechanical fuel pump and a return line 4-port sending unit.

I wanted to again thank everyone for their input as I worked to figure out this issue.
 

SquareRoot

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because I don't care where you live 210-215 is not anywhere near normal even for hot climates, even modern injected engines don't run that hot. The Max normal operating temp of the Chevy engine is between 190 and 200....period.

I can prove you wrong. Everyone of my modern injected vehicles run at a constant 210, including my Duramax.
 

gmbellew

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the stock thermostat on a tbi 350 is 195 degrees (with a 180 degree as optional). it would take one heck of a cooling system to keep the coolant at the thermostat opening temp under any sort of load...
 

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I wanted to return to this thread and source the appropriate 'return' fuel pump and 'return' sending unit to get this upgrade done before it gets hot.

Thoughts on the appropriate year model parts (fuel pump and sending unit) I need to look for?
 

SirRobyn0

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I wanted to return to this thread and source the appropriate 'return' fuel pump and 'return' sending unit to get this upgrade done before it gets hot.

Thoughts on the appropriate year model parts (fuel pump and sending unit) I need to look for?
I can help you out with this. I can't remember all the details of this thread but I believe you need a sending unit for a carbureted rig?

The right side is nearly impossible to find and when you do will cost twice what the left side does. The solution I have come up with is to use the same Left side sending unit in both sides. It'll work just fine, the only thing is on the right side the lines will face towards the outside of the truck so you just run a little longer rubber hoses to loop it back to the hard lines on the truck. I've done that on customer rigs as well as mine with zero issues. I can snap a picture of how my lines are routed using this method tonight if you want (my truck has a dump kit so it's easy to access).

Here is the part # for 3 line with return. FG05F, Spectra and Precision and other manufactures use that same part number you should not have a problem ordering it from the parts house of your choice or online. FLS1001 is the ACDelco part # but they are out of production as far as I can tell.
 

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