problem with fuel delivery to carburetor

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problem with fuel delivery to carburetor

Postby Marcin » Sun Sep 15, 2024 8:06 am

Hi

Since last Thursday I am a new owner of European version of Monza Spyder 4.3V8 year 1976. Car engine was working before transport. After unloading is started once and not working any more. When I put gas into carburetor directly engine works. So I guess that could be fuel line issue. Tank was almost empty so maybe something from the tank blocked the line. I am still waiting to have delivered service manual so maybe you could suggest what to check first and how to start investigation? Is it any filter on the line? What says service procedure in this case?
Chevrolet Monza Spyder 4.3V8 1976
European version
Marcin
 
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Re: problem with fuel delivery to carburetor

Postby Monza Harry » Wed Sep 18, 2024 12:21 pm

Your car is 48 yrs. old, so many changes may have been made over the years. In stock form the only fuel "filters" are located in the tank (commonly called the "sock" that attaches directly to the pump inlet), and the filter in the carb at the place where the fuel line attaches. Many people have inserted an inline fuel filter to supplement the marginal stock offerings.
This is a good place to start checking, also the oil pressure switch contrthe power to the pump, next place to check to insure that the pump is working. Get back to us if these don't solve your problems. Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)
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1978 Chevrolet Monza 2+2

Re: problem with fuel delivery to carburetor

Postby Monza Harry » Wed Sep 18, 2024 12:23 pm

Oh and welcome to the board! Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)
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1978 Chevrolet Monza 2+2

Re: problem with fuel delivery to carburetor

Postby monzaaddict » Fri Sep 20, 2024 12:08 am

I am assuming you bought the silver 76 spyder that was for sale in Poland. My guess is the fuel pump located in the tank is not working.
When cranking the pump is powered by the starter relay through the oil pressure switch on back of engine by distributor to the fuel pump circuit of fuse panel under drivers side of the dash.
Once oil pressure has built up power is fed from the ignition switch through the same oil pressure switch to the fuel pump circuit of fuse panel under drivers side of the dash.
The wires run back under the drivers door sill plate to hatch area and down to fuel tank.
The 3-prong oil pressure switch often goes bad.
You can bypass the oil pressure switch by jumping the two opposing terminals (3 terminals- left, top and right) jump the left and right terminals and power the fuel pump with key on.
You can turn the ignition to on and run a jumper from one of the powered circuits in fuse box under dash to the fuel pump fuse (bypassing the oil pressure switch portion of harness completely and powering the fuel pump) and see if the fuel pump starts to run.
If not, go back to the fuel tank and remove the connector for the pump and gauge. See if there is power at the connector. See if there is ground - ground goes through the plug behind plastic jack cover inside of hatch. If you have power then the pump could be bad or the connector pins and or cables on fuel pump assembly may be corroded. You can cut/pry off the 1/8" push on clips that hold the wires to the pass-through connectors on fuel pump assembly, remove everything clean the connections and reassemble.
Jay Hovick on here and Facebook rebuilds sender assemblies. Replace the pump and screen while you are in there. I used Spectra SP1156 pump and AUTOBEST F201S strainer. The coating on the wires was peeling so I removed it and replaced it with 3/8" dr25 fuel resistant shrink tubing.
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Re: problem with fuel delivery to carburetor

Postby Marcin » Sun Sep 22, 2024 1:14 pm

Yes. I have bought that blue/silver one.

Thanks for all advices. I am going to check
Chevrolet Monza Spyder 4.3V8 1976
European version
Marcin
 
Posts: 5
Joined: Mon Sep 09, 2024 11:41 am
Location: Poland/EU

Re: problem with fuel delivery to carburetor

Postby Marcin » Mon Sep 23, 2024 2:44 pm

OK. So the first issue - broken fuel pump fuse. After replacement engine started. Interested thing is that during starting at the beginning there were 2 red control lights on "oil/temp" and "brake". After a minute or two engine stopped. And there were no way to start it again. Now fuse looks OK (BTW do you know any tool to remove glass fuses easily not breaking it?). But what I have noticed during start only red "brake" control is on. That "Oil/temp" is off. So I guess oil pressure sensor seems to be broken, right?
Chevrolet Monza Spyder 4.3V8 1976
European version
Marcin
 
Posts: 5
Joined: Mon Sep 09, 2024 11:41 am
Location: Poland/EU

Re: problem with fuel delivery to carburetor

Postby Marcin » Mon Sep 23, 2024 4:39 pm

monzaaddict wrote:The 3-prong oil pressure switch often goes bad.


Hi
I have checked some shops and for Monza V8 they have oils pressure sender but with 1 connector. With 3 they are saying that is not for 262V8 - it is for L4 or 305V8. I have 262V8. The seconds question is where could I find this sensor located?
Chevrolet Monza Spyder 4.3V8 1976
European version
Marcin
 
Posts: 5
Joined: Mon Sep 09, 2024 11:41 am
Location: Poland/EU

Re: problem with fuel delivery to carburetor

Postby monzaaddict » Mon Sep 23, 2024 8:40 pm

located near distributor at back of engine
pry on metal endcaps of glass fuse to remove.
part number 3986857
https://www.ebay.com/sch/i.html?_from=R ... =0&_sop=12

https://www.rockauto.com/en/partsearch/?partnum=3986857
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Re: problem with fuel delivery to carburetor

Postby Marcin » Tue Sep 24, 2024 3:43 am

Thanks!!!
Chevrolet Monza Spyder 4.3V8 1976
European version
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Posts: 5
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