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Really need to get my daily driver

2194 Views 79 Replies 9 Participants Last post by  KAMjenII
1984 Monte Carlo Base Converted SS Body

305 LG4 Motor with 305 H.O. Heads
Edelbrock Performer EPS Intake Manifold

Edelbrock 1902 AVS2 Series 500cfm Carburetor (Manual Choke)

De-smogged/Non-Emission/Non-Computer Setup.

I bought this car a year ago, replaced things, and as I was replacing the distributor with the distributor removed, I overturned the engine...have had idle and acceleration problems ever since.

Car History: I was told at the time of purchase that this was an SS Monte Carlo...I was also told that the motor was a rebuilt 350 with 46,000 miles on it...I didn't know much about the SS Monte Carlo, it just looked like one to me.

Since this was to be my daily driver, I wanted to buy new parts and replace the old parts and jumped into Monte Carlo SS Facebook groups and online forums to learn how to replace everything.

First thing I learned is that this wasn't an SS Monte Carlo by looking up the VIN # and other visual things like black trim instead of chrome trim...the original V6 motor, computer, and emissions were ripped out and replaced with this "Rebuilt 350 with 46,000 miles on it".

After looking up the engine block and head casting #'s, I learned that this motor is actually an 1983-1984 305 with 305 H.O. heads...

It had an Edelbrock Victor Jr. Single Plane Intake and an Edelbrock Performance Series 650cfm electric choke carburetor...I was told both were too big for my 305 motor, and to swap them with a smaller rpm range and cfm rating. I swapped with what I have now (listed in the beginning) and things where better but my timing seemed incorrect and after spending months of playing with it, I decided to replace and inspect the timing chain set. I could never achieve 600 rpm to correctly set factory timing settings.

First thing i found was the Tach was set for a 4 cylinder engine, instead of an 8 cylinder engine, I set it for 8 cylinder. I replaced the timing chain set with a Cloys double roller and installed it correctly. While I was that far into the motor, I wanted to pull the camshaft so I knew exactly what it was I was working with, but nobody could seem to guide me so I slapped the timing chain and cover on without checking it out. I have no idea what the camshaft specs are.

Second thing I found wrong was the timing tab on the timing cover. With the prior 2 o'clock TDC position timing tab fully exposed, I used a spark plug stop tool/TDC finder to find the motors true TDC...seeing how everything else was wrong...the timing marked showed TDC was actually 12 o'clock, not 2 o'clock...so I swapped it with the correct timing tab.

The 3rd thing was the harmonic balancer was the 8" instead of the factory 6.75", so I swapped it for a 6.75".

The carburetor distributor vacuum advance was also plugged up as an emissions setup, so I plugged it up as non-emissions due to my de-smogged/non-emissions setup.

The engine seemed to run and idle a lot better.

Next was my fuel pressure...I was running an electric fuel pump but after it failed I swapped it out for a mechanical fuel pump. The new mechanical fuel pump was pushing 9psi of fuel pressure, so I installed a fuel pressure regulator and the current pressure is at 6, but can be adjusted to 4psi.
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I bought this car a year ago, replaced things, and as I was replacing the distributor with the distributor removed, I overturned the engine...have had idle and acceleration problems ever since.
This is the only question i could see in your post...?

Have you used a timing light to set the initial timing??

Any idea of the brand or the type of distributor in the engine now??

Symptoms sound like the timing is too low.
 

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Discussion Starter · #3 ·
My problem I'm having now is I'm too advanced, 24° initial @ 800-900 rpm and 52° total timing @2500-2800 rpm, checking with my adjustable timing light.

However if initial timing isn't 20-24°, my throttle response at take off is late and the engine "skips" as if it wants to stall if I put the gas pedal to the floor. With the engine first warmed up, in Drive the rpm is 600-700, it fluctuates. Once I'm accelerating from 1st to 2nd gear, it seems a bit rough, then smoothes out from 2 gear and on. Shifts about 1700-2000.

As I'm letting off the gas and braking, the downshifting seems late, and at a complete stop, the rpm's in Drive have raised to 700, and if in Park the rpm's are 1000-1300 rpm's and if I shut the engine off, it diesels.

Adjusting the carburetor idle mixture screws really have no effect if little until I take one completely out, then the engine stumbles wanting to stall.

I'm told I'm too lean and to check for vacuum leaks. I retorqued the intake manifold and carburator to factory specs and sequences. However, because my idle fluctuates, spraying the areas down with starting fluid and listening for rpm to rise is ineffective.

I have tried the smoke vacuum leak check. I bought a cigar and blew into the PCV hose attached to the carburetor, and if I had a vacuum leak the smoke would leak out of wherever was leaking...the only place smoke came from was the top of the carburetor, nowhere else...can't be a vacuum leak..
 

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Discussion Starter · #7 ·

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Put the old carb back on and try it. See if things
Change if it doesn't change anything at least you have eliminated the carb. Something you have done is causing your problems. Are you sure you installed the timing set correctly? I would also go back and do a reinstall of the distributor pull it find tdc and reinstall and make sure your plug wires are installed correctly. Do 1 at time so you will know what corrected the problem. If none of these fixes your problem, I would guess you have a vacuum leak at the manifold some where.
 

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Discussion Starter · #13 ·
I would guess you have a vacuum leak at the manifold some where.
I agree, but with the smoke test with the engine shut off and warm, I get no smoke leaking from anywhere, except the top of the carburetor because I have no air filter housing...

While installing the manifold, I did use RTV silicone on the water ports. I heard that, if not done correctly, will cause a vacuum leak you will only find by removing the intake from the engine...
 

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Are you setting the timing with the vacuum advance unhooked from the distributor and hose plugged to prevent a vacuum leak.

Can't set timing with vacuum advance can connected.

With the feed passages at the bottom of the fuel bowl, Carter AFB/Edelbrock Performer/Edelbrock AVS design carburetors have a tendency to sludge up the main and idle feed passages if fuel isn't well filtered....it sounds like you might have some plugged passages if you can get no change until the idle mix screw is completely removed.
Good fuel filtering is mandatory with that style carb.
 

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Your timing values are crazy but some of that is running up RPM with no load on the engine. That is a situation where the engine will rev very high on very little throttle therefore the manifold vacuum is high which pull in a lot of vacuum advance on top of the centrifugal which is not a condition that would occur out on the road when the engine is working to overcome weight and drag so the throttle is much more open for the same RPM therefore manifold vacuum is lower taking the vacuum advance amount down to as far as null so the engine is likely seeing only centrifugal values at high RPM.

24 degrees initial is an awful lot. Initial is set and tested with the vacuum advance disconnected and the feed from the carb plugged. A base setting of 24 degrees would be something a racing cam would require. A factory cam typically uses something in the range of 6 to 12 degrees. If your reading 24 with the vacuum advance out of the system it would be a strong indicator that you have the distributor a tooth off which is a common problem on the SBC where R&R’ing the distributor caused by how the oil pump drive tang carries a rotation as the distributor gear disengages from the cam’s driving gear.

It is unfortunate that you didn’t degree the cam while it was out. Being a flat tappet the tippets are mated to their lobes so hopefully you kept track of what tappet came from which lobe and put it together the same way it came apart. Not that it can’t be done installed, you need a dial indicator with magnetic stand, a degree wheel and a sober friend makes the job easier than doing it by yourself, but it can be done alone.

The crankshaft key way aligns with number 1 and 4 crank throws pointing straight up. The dampers typically are showing the timing marks for setting the ignition either 2 degrees or 10 degrees before the keyway in the clockwise rotation direction of the crankshaft. Timing case covers, timing tabs and dampers are or need to be matched sets. Nothing wrong with running a 350’s 8 inch damper on a 305 as long as the timing tab matches. Actually a lot right about that as the bigger damper does a better job of doing what it’s there for than the 6.75.

I’m guessing this has an automatic transmission, my caution is unless purpose built to be manually shifted you will find doing so greatly shortens their life. The manual shift from the factory is intended for using engine braking on long down grades, thus seldom used. Manual shifting engages a one way roller clutch in the transmission which is woefully under sized for constant use. When these fail and all those rollers come out it makes one hell of mess inside the case.

Sounds like you got stung a bit on this, there are a lot of scammers out there.

Bogie
 

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Discussion Starter · #18 ·
Are you setting the timing with the vacuum advance unhooked from the distributor and hose plugged to prevent a vacuum leak.
I was setting it without the vacuum advance connected.


With the feed passages at the bottom of the fuel bowl, Carter AFB/Edelbrock Performer/Edelbrock AVS design carburetors have a tendency to sludge up the main and idle feed passages if fuel isn't well filtered....it sounds like you might have some plugged passages if you can get no change until the idle mix screw is completely removed.
Good fuel filtering is mandatory with that style carb.
Yea I had a filter on it, the Spectre chrome canister type, but it became bad and rattled. Can't say how long I drove it like that, but not 6 months or more...I did use about a quarter tank of ethanol gas in an emergency, I heard ethanol gas ruins these carbs, but was told in an emergency situation would be OK. I removed the carburetor about a week or so ago and sprayed carb cleaner into the idle mixture screw holes, top and bottom of the carburetor but not the carb fuel inlet.
 

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Discussion Starter · #19 ·
24 degrees initial is an awful lot. Initial is set and tested with the vacuum advance disconnected and the feed from the carb plugged. A base setting of 24 degrees would be something a racing cam would require. A factory cam typically uses something in the range of 6 to 12 degrees. If your reading 24 with the vacuum advance out of the system it would be a strong indicator that you have the distributor a tooth off which is a common problem on the SBC where R&R’ing the distributor caused by how the oil pump drive tang carries a rotation as the distributor gear disengages from the cam’s driving gear.
Today I'm going to set the initial timing (without vacuum advance connected) starting with 6° and work my way up to 14° and test everything in each of those settings with the vacuum advance connected. I will check timing advance once the vacuum advance is connected...I'm using the ported vacuum port on the carburetor for my distributor vacuum advance.

If I'm going to remove the distributor, I'm going to replace the mechanical advance springs to lighter springs while I have the distributor out. But this is this position the rotor was pointing when I dropped the distributor in...#1 plug wire is plugged at this cap post...
Motor vehicle Automotive design Electrical wiring Vehicle Automotive exterior


Another concern in this area, is when I'm rotating the engine to TDC on compression stroke. I'm doing it by myself most of the time and sometimes I turn the balancer TDC mark slightly too far past the timing tab TDC mark...during those situations, is it OK to turn the balancer back to line up the marks or would I need to rotate the engine clockwise twice back on compression stroke lining up the timing marks ? Exactly how straight do these lines need to be lined up ?
 
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