Heat Soak

[letank]

the least damaging way, lift up the hood a tad

viewtopic.php?t=338&sid=3eba7940bdf6438 ... f6010a8ccc





and yes facing rearward is the way, there is a low pressure in front of the windshield that will suck out more air from under the hood

this is also why the fan shroud has no lower shroud, to use that low pressure under the engine to suck more heat from the radiator

[devildog80]

Perfect logic, so will point louvers to the widshield. Also going to go back to mechanical fuel pump, which should give better cooling of fuel line, but keeping the electric in line for initial purge after sitting for some time. Might not be needed once I get 4 bbl setup done with mechanical pump, but its there if needed.

Spacing the hood up just a tic would have same results, or better, than louvers.
Thanks for feedback

[OldFarmTruck22]

That's what I have. I just didn't call it the right thing.

What I see in the picture is not DEI or any other company, proper fuel line insulating wrap. Its foam.

[JWestfall]

Not my picture. I haven’t posted any pictures of my engine. I ran the fuel pump for a few seconds and pumped the gas once after it sat hot the other day just in case it was fuel starved instead of flooded. Didn’t help. It’s definitely flooding from the heat soak.

[seventynine]

In the first picture you posted it looks like your fuel filter is pointed downward a bit going towards the carb. This could be a relatively minor issue but it can effect fuel flow and vapor lock. The filter should be angled up a little with the vent/return at the top.

In the last pic you posted it looks like you have it right so maybe you addressed this or the first pic was an optical illusion.

[Srdayflyer]

yeller is correct about the high and low pressure areas in the engine compartment area, the first thing about the fsj's is they sat on way lower size oem tires like e78 bias ply tires there was also a plastic air dam attached to the front bumper which lowered the airflow under the body creating the low pressure area drawing the heat out of the engine bay, fast forward to today 2/3/4/6 inch lifts ,31/32/33/35 inch tires people ditched the airdam for looks , the big change was carbs themselfs
look at bj's or team waggy for carb gaskets and you will see 3 in a gasket set there is a very thick molded gasket that gos on top of the manifold (heat shield), then a crush spacer and then a base gasket, before i removed the carb for f.i. mine was attached with bolts and not studs, my holly kit had studs to replace the bolts does yours have that molded base gasket?,i had a big cooling issue and learned a whole lot fixing it i spoke to stant regarding stats and i learned 1 huge thing for all those who own newer vehicles when you open the hood and see that plastic cover/s they are not there for looks they are part of the engine bay cooling ,yes cooling squeeze in all that crap for emissions, a/c and throw in a turbo or 2 and you have heat problems, anyway so take into consideration any jethro bodine cooling fixes before assuming that they will work IMO

[letank]

Re the low and high pressure, this is correct, hence the cut out at the bottom of the shroud (don't try to close the opening, I did it for a test, and for sure the temp gauge showed a higher reading)

BUT, the earliest years did not have the airdam under the bumper, and as I have said before, I never bothered with hood up even in 120F trips in Arizona... no problem with restart... of course this is late 1980ish with a different gasoline formulation.

BUT, look at the newer vehicles, every "truck" seems to have fender or hood vents... so... time for a hack job!

And as a note some of the newer temp gauges seem to use an average measurement over a certain period to avoid freaking out the driver... no more temp gauge entertainment that we have on our rigs... add a trans temp gauge, it gets better to see who is cooling the fastest.

[Sarahclark]

Ok, so the OEM 2 bbl carbs used were the MC2150 on my '84 GW. As all is set to run at OEM spec, except the 401 engine vs original 360 engine, but all other pieces/parts OEM. I would think there should be no hard start after full operating temp just light city driving to the store, then sit for 10-15 minutes.

TA has a slightly different setup with his '71, but nothing really out of the norm for these old trucks, compared to OEM. So thinking he should not be having the same issue, but seems to have identical issue. Could it be as simple as different type fuel from OEM to now causing these type issues?

It's interesting to hear about the similarities between your '84 GW and TA's '71, especially with both running on OEM setups.

[devildog80]

Ok, so the OEM 2 bbl carbs used were the MC2150 on my '84 GW. As all is set to run at OEM spec, except the 401 engine vs original 360 engine, but all other pieces/parts OEM. I would think there should be no hard start after full operating temp just light city driving to the store, then sit for 10-15 minutes.

TA has a slightly different setup with his '71, but nothing really out of the norm for these old trucks, compared to OEM. So thinking he should not be having the same issue, but seems to have identical issue. Could it be as simple as different type fuel from OEM to now causing these type issues?

It's interesting to hear about the similarities between your '84 GW and TA's '71, especially with both running on OEM setups.

Since my comment above, I replaced the starter cable from solenoid. When doing that, found the inside nut on solenoid post was loose so tightened up, and installed the new cable. Not too many miles driven on it yet, but working much better, and seems to start better when warmed up. Actually sounds different just turning over, even on cold start, then it did before working on the new cable. Loose connections will leave you stranded, so glad to have fixed that one.

[devildog80]

So got four quick errands ran yesterday, and truck started each time, but was getting slower each time. Seems the loose connection and old cable was the hot no-start issue. Now to get the best battery I can afford to put in it, and have this issue whipped. Thanks all who assisted, and sharing to help someone else.

[candymancan]

5.9 ZJs had hood louvers. Mine has em. I noticed they really vent heat out a lot if you sit and watch you can see the heat waves coming out

I have 3 im selling. A pair left n right and a 3rd right one i believe.

If anyone is interested lol. Im broke and really could use the cash haha

[Srdayflyer]

yeller is correct about the airflow, when these rigs were new they sat way lower and sat an 78/15 bias ply tires for most part
the front bumper had and air dam attached to it and that created a low pressure area under the truck quick education on pressure high pressure flows to low pressure ,i.e high p (ram air) into the eng. bay low p under vehicle draws air flow thru the eng. bay. larger tires,raised vehicles and you change these dynamics, also jeep had a set of of base gaskets under the oem carb which a lot dont use when they do a carb swap , and ten the problems start there have been articles and that issues has been covered here before, and i had that issue as a p.o. ditched those gaskets on my rig , and i reinstalled those gaskets and spacer and the problem went away, but iv'e switched to holly f.i. as i didnt like the way the truck ran with a carb and i have huge options of fuel control with the holly from the drivers seat, and yes i use the base intake (oem) spacer . hope this help a little