simo

This is the GM fix for the fuel boiling problems of the L69.
This is what I got off e-bay.

This is for Customer comments of vehicle surge, hesitation, and/or stumbles after the vehicle has reached operating temperature, then parked and restarted, (Hot Soak) may be received. This condition is caused by a large temperature difference between the carburetor fuel bowl and the fuel delivered from the fuel tank. This condition can be eliminated by the installation of an auxiliary blower fan, which reduces the temperature of the fuel bowl during a hot soak. The fan is designed to operate at an engine coolant temperature of 106 DEG C (220 DEG F) and stay operational until the coolant reaches 90 DEG C (195 DEG F). This will maintain a fuel bowl temperature of approximately 74 DEG C (165 DEG F).

JamesC

iTrader: (5)

I've heard about the 'fix'. Could you snap a few pics of the pieces out of the box?

JamesC

f1ls1

iTrader: (2)

There were three different fixes for the Vapor lock problem. Pontiac used a bigger fuel pump the same pump was used on the sbc 400.Chevrolet used an electric intank fuel pump to feed the engine mounted pump. And you had the blower kit which was worthless. Either of the first two I listed works the best.

aaron7

iTrader: (7)

Where does this thing mount??

8t2 z-chev

mounts under the RH fender,about in the area
behind the marker light,hose comes out behind
battery. Found one of these blowers installed on an
'84 L69 z28,blower motor had late '85 date code on
it,was probably installed in 1986.
BTW the same blower is found on v6 fieros-used
to blow cooling air on the coil and alternator.

MY87LT

iTrader: (2)

The blower kinnda looks like the kind my 78 Nova had for the rear window defogger without the hose of course.

David M

Very cool! I always wondered what these things looked like in the box. My '86 LG4 Z28 had one of these, and I didn't know what it was until I sold the car! Thanks for the pics.

L695speed

So how do we know what fix each of our cars have? I highly doubt I have the blower as I don't think I see it on my car. But I don't recall any problems and Dad never mentioned anything about the carb having problems.

Dens71TA

iTrader: (5)

Look at the relays next to the brake booster. If there is relay mounted to a L-shape bracket and looks out of place the car has the in-tank pusher fuel pump. '84's L69s produced about mid-year and up will have this installed from the factory.

Another fix was a carb base gasket with a big built-in metal heat shield.

L695speed

Well with my car being built in July I would say theres a good chance that I've got the in-tank pusher fuel pump fix. I don't see anything in the photos I have that show the relay but I do remember some weird stuff back there.

MY87LT

iTrader: (2)

Apparently I have the 3 psi electric fuel pump in the tank after some searching. Funny though, in my owner's manual, it mentions the blower for the carb.

okfoz

Interesting,
My 87 Formula LG4 did not have anything like that . What it did have was an in-tank fuel pump and a Mechanical Fuel pump on the front of the engine.

John

MY87LT

iTrader: (2)

Yea, your lg4 and mine are the same with both the mechanical and electric fuel pump.

MOTOCROSS

So, if your electric fuel pump goes out, can the mechanical pump pull enough fuel through it to feed the motor? My fuel pressure drops after the motor warms up. Still runs OK, but I don't like it. I have an 84 Z28 L69. Now has a strong 350 with Holley 750 and a Holley mech fuel pump. Any suggestions??

okfoz

I think the mechanical pump is more or less adequate, however the problem with the engine mounted fuel pump is it creates a low pressure while sucking fuel from the tank. With the lower pressure it actually increases the chances of vapor-lock or boiling. Any liquid will boil at room temperature when put under enough vacuum, you add that to the small engine compartment and the exhaust so close to the fuel lines and it's a problem waiting to happen.

Keep in mind that they did not completely drop the L69 as they used the engine in the Monte Carlo until the end of the 1987 MY.

The in tank FP will reduce this because it is increasing the pressure to the carb. If you want to increase the pressure, the in-tank fuel pump is not a bad idea...

the209bnr

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FJA1791

iTrader: (3)

Do you have any pictures of relay location and was the carb gasket a OEM gasket?

Thanks
Frank

Jon Friesen

I had the dealership install the blower kit on my '86 Z28 Lg4 right after I bought it new in '86. It still comes on after the car has been shut off. It does stop the car from surging when it is hot.

the209bnr

can you post up pics of this inside of the vehicle engine bay?

stealtht/a

iTrader: (1)

Oh, that's what that was!
I had a parts customer came to the shop with that running non stop. We couldn't figure out what it was doing there. His was an lg4 87 5 speed firebird.