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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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Ok.

You changed to much to fast. There are to many "could be's" at this point.

I would pull the motor and then start by pulling that balancer, timing cover, and drivers head.

Here is a easy to understand video on degreeing a cam.

Ok now thats done and everything is set at to put your heads on( new gaskets).

Ok now our timing is set and we know what our cam numbers are. You can put on the timing cover, balancer, then rockers. Inspecting the pushrods and rockers where the pushrod hits the rockers at that time. Give the springs a look while your here looking for any damage etc.

Ok now our valves are all correct. You can throw on the intake. Before you put the gasket on set the clean intake on the heads "dry" with no gasket. Your looking for any gaps between the head and intake. You can set a low profile led light that wont hit the intake in the valley and with the lights out and shop dark(perferably at night) you can often see any gaps easily. You need to cover and openings like the distributior hole etc of course.

If you have gaps its not a big issue. Just mark that area with a permanent marker so you know you need some gasket filler in that area.

Ok pull the intake and remove the LED light. Then put down new gasket and the correct rtv before installing the intake. Inspect the cam gear , chevk the function of the vacume advance, then with the engine at TDC install the distributior.

Ok now onto the carburatior. Same deal with the LED light set light inside the intake then set the clean carb on the intake dry with things tapped off then with the lights off check for any gaps. All your looking for is areas that need rtv. Put down the gasket with fuel resistant rtv on the top and bottom then torque it down. Oh shoot you left the led in there. Yea remove that before putting the carb on.

Ok. Now we have a engine that is timmed correctly and is air tight. Get some new vacume lines using the old as refrence and one at a time swap out tge old lines for the new.

Make sure you maintain any pcv system. If you have an egr make sure its hooked up. If it has the egr blocked off make sure the plate has a good gasket and gasketrtv so it is not a source for leaks.

Now your ready to put the engine back in(remove the distributior cap temporally). Once in you can install new exhaust gaskets and bolt up your exhaust. I like remflex exhaust gaskets.

Ok engine us and all the electrical is hooked up. Now you have eliminated several "could be's" you can get into playing with the carburatior and timing adjustment knowing whats going on with the shortblock.

This is more a time thing then cost. Your into it for mostly new gaskets. You will need a degree wheel and dial indicator to find the cam numbers. One of those things you buy a good one once and if you dont loose or loan it out for it to never return you wont need another. You may be able to borrow or rent these tools.


This is a good amount of work. But it is worth doing the detective work writing down your results then saving them in a notepad file somewhere so you know whats going on. That engine could have a massive amount of combinations it could have done to it over the years. Doing the detective work will give you a foundation to further tune.
If you dont do this your dealing with the "could be's" hoping you get lucky.
 

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Here in the northwest corner of what passes these days for a nation we’ve been on E10 for about 35 years. In that time I have never had a problem nor seen a problem that I can say is a fault of E10. Maybe our regional refinery in Anacortes is unusually good at blending or maybe it’s Alaskan crude as a foundation or they use better booze in their blend but whatever the cause I have yet to see a part failure that I could conclusively grunt and say alcohol did it.

Couple years ago on my Heritage I was riding to a friends house in Yakima and decided to take the scenic route over the back side of Mt Rainer rather the the Interstates. When on my hard tail which only has a 3.1 gallon king tank on it I have to stop at Greenwater which is the last fuel stop for the next hundred miles and from my house to Greeneater burns out 70 miles of fuel. As a habit I stop there on the Heritage just to cover my contingencies but it’s 5 gallon tank isn’t usually a problem. This last trip the only fuel they had at Greenwater Chevon was leaded so I just decided to press on rather than contaminate the Harley with leaded fuel which has never been in that tank nor in the tank of the hard tail.

Bogie
Leaded fuel at a regular pump is unusual.
Ethanol will absolutely eat rubber parts not meant for exposure, not to mention all the solvents like toluene that are in pump fuel now---we use toluene to soften tires, and it will simply melt them if you get too aggressive with the amount and duration.
I don't do driveability anymore buy have heard that some pump fuel is not E10, but E30. Will work in FI engine with feedback but carbs are just controlled leaks and don't understand.
I should invest in the test kit.
 

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Yeah I find that unusual as I don’t think Greenwater is Indian reservation land. Frequently you can find 100 octane leaded at reservation stations. But no where else. One weird one not to far from me is an independent Seattle station getting up toward Lake City has it. But sometimes reservation land is a few acres surrounded by city usually on water where the Indians retain fishing rights that weren’t too far out of town back when but the cities grew up around these reservation holdings. And then again the station in Greenwater is right next to the river so it might be one one of these treaty fishing spots.

Anyway the backside of Mt. Rainer is a great ride during the week as there isn’t much traffic. A lot different on weekends in that regard but mostly locals going camping or fast water fishing as except for the Sunrise outlook open only in summer there isn’t any services or lodging that attracts he casual visitor most of that is Paradise Lodge on the west side facing and close to Tacoma. The back side is popular in winter because of a big ski resort just before the park but the park is closed and snow removal stops at the park entrance. So unless your ready to handle 15-20 feet deep snow there ain’t no way in.

Keeping my motorcycle racing on the track or off road or at least I did before getting too old, riding the highway I‘m just a gray beard Harley cruiser guy that puts his feet on the highway pegs and watches the scenery roll by.

Bogie
 

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Discussion Starter · #44 ·
Okay guys I got my engine to run smoothly at 12 degrees before top dead center... I haven't set total timing yet and I haven't plugged up the vacuum advance yet but my vacuum advance is on the ported connection on the carburetor.

While I had the distributor out I went ahead and put in lighter mechanical Advanced Springs.

The engine doesn't like the idle below 900 RPMs and if I put it in Drive it drops down to 400 RPMs and if I hit the gas it backfires and dies. This happened at Six Degrees before top dead cylinder.

I went from 6 degrees before top dead center under to 12 degrees before top dead center with the idle at 900 RPM and just took my timing light and Advanced the distributor to degrees and jumped in the car and reversed it and mashed it and drive..

Everytime it bogged and hesitated a bit when I mashed the gas pedal, the only difference I was getting was the amount of power once the power caught up with the mashing of the gas pedal.

Starting to think that the accelerator pump is starting to be the culprit of my issues...

I bought a new accelerator pump but I'm also seeing that you can adjust it before installing a new one... I'm going to try to play with those three accelerator pump link holes and see if that fixes my bogging problem before I replace it with a new one.

The engine is idling a little smoother as well so I'm also going to spray a carburator cleaner around the vacuum hoses, intake, and carburetor base to see if my rpms shoot up

I got everything on video but I'll have to edit it into one video so if you guys want that let me know.
 

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Discussion Starter · #46 ·
I removed the accelerator pump link down a hole and

Hooked up the vacuum advance and initial timing advanced 20° from the 12° initial without it connected making it 32° initial...

Connected to ported/timed vacuum on the carburetor.

Idling got worse, ran high and in order to tame it, I have to retard the timing which worsens the take off acceleration...so I set initial timing to 30° with the vacuum advance connected. In drive it sounds fine, the throttle response was better, but when I mashed the gas pedal it backfired, stalled, and the carburetor caught on fire, I had to jump out of the car and blow it out.

Things don't start to get bad until I connect the vacuum advance...about to say to hell with it and run without it...how bad does it hurt fuel economy from driving with it connected ?
 

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I also still have dieseling at shut off... I just have to shut the engine off and drive to eliminate that from happening.
900 RPM idle is awfully fast, why so high? Unless it has a really big cam this should idle around 550-600 RPM. The high idle will contribute to run-on though that isn’t the only reason for run-on.

Bogie
 

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Discussion Starter · #53 ·
If you have an electric choke check its operation. Just a quick check that can be done in around 2 hours. But will eliminate yet one more what if.
I have a manual choke.

I also noticed that I only torqued my intake manifold at 25 ft lbs. I've seen different torque specs ranging from 30 to 45...so I did 35 ft lbs in sequence since I don't have aluminum heads.

I also torqued and snugged my carb to intake to 15 ft lbs. since I have and aluminum intake manifold.

I also replaced the carburetor accelerator pump...

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Idle speed is very cam dependent, a stock cam 305 will idle around 5 to 6 hundred in gear and about 700 out of gear.

Given this engine has been touched before you got and sold to you as a hot rod who knows what cam is in there. Getting vacuum readings in these RPM ranges is a quick way of getting a rough idea of what kind of cam is in there.

Another possibility is the cam wasn’t timed correctly if somebody was in there previously for either a cam and or timing set replacement? It’s never easy picking up someone else’s work.

Basic timing is done with the vacuum advance disconnected and the vacuum source plugged. Most emission crammed 305’s only ran 4 to 6 degrees static base advance. Vacuum advance varies a bit based on which year and model canister is on the distributor but these usually have a range of 7 to 12 degrees.

The mechanical advance if idling 900 RPM and your using soft springs may also be turning on which will interfere with getting a good base setting. I much prefer doing this work with the timing tab rather than a dial back, there are some ignition systems that fake the dial back and you end up not knowing we’re tge timing really is.

Big cams like a lot of base advance and require a fast idle, this of course leads to a high stall converter to give some RPM space for the engine to idle. But again we don’t know anything about the cam so we don’t know if the problems your having are from a big cam fighting a stock stall converter for idle speed, or something else is going on.

A lot of what you describe hints toward the direction of a bigger than stock cam against a stock stall converter, but this isn’t conclusive by any means and without cam lobe timing data, like I said vacuum readings as it idles in neutral or park to in gear can give a little insight as to what might be there without needing to do a deep dive on the cam straight away.

Bogie
 

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Discussion Starter · #56 ·
OK guys I found two issues...first issue I found is my carburetor idle mixture screws are broken, sent to me like that from Speedway Motors with the "New In Box" carburetor when I bought it...there isn't any tapered ends on them...
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The second issue I found is 1 of my spark plug wires are bad, so I've been running on only 7 cylinders, and maybe only 6 cylinders while pulling one plug from the engine, it wasn't connected all the way, not sure if it was the one I found to be faulty...tested the OHM resistance on all and this one gave no reading and it's rusted inside...wires are a year old.
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You'll want to check closely, it is likely the tips of those idle mixture screws are broken off wedged into the bottom of the holes, and either partially or fully blocking one or both of the idle feed passages.
if the tips aren't stuck in there, then the idle mixture would just be maxed open and pig rich at idle with what is left of the screw threaded into each hole..

Cheap spark plug wires if that is rust....quality wires have stainless terminals on them.
 

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Discussion Starter · #58 ·
You'll want to check closely, it is likely the tips of those idle mixture screws are broken off wedged into the bottom of the holes, and either partially or fully blocking one or both of the idle feed passages.
if the tips aren't stuck in there, then the idle mixture would just be maxed open and pig rich at idle with what is left of the screw threaded into each hole..
Well, I removed the carburetor about two weeks ago to see if my throttle butterflies were getting caught on my intake manifold causing a sticking throttle issue once I accelerate and left off the gas pedal, rpm increases, and dieseling at shut off. Also at idle when I flick the throttle by hand or gas pedal, it takes awhile for the idle to come back down, instead of coming down as I release the throttle linkage.

While I had the carburetor off, I sprayed it all down with carburetor cleaner. Removed the idle mixture screws I sprayed inside of the of both sides of both idle mixture screw holes and the fluid came out of both ends of both holes...if the needles were stuck, would fluid shoot out both ends ?
 

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Discussion Starter · #59 ·
Cheap spark plug wires if that is rust....quality wires have stainless terminals on them.
These are 10.5mm plug wires and OEM plugs...others are telling me to get platinum plugs, but what about the wires ?

Should I get the OEM 7mm or another set of quality aftermarket 10.5mm wires with the platinum spark plugs.

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This comes from excessive tightening somewhere either at the factory, by you, or the carb was a return sold as new.

I’s expect if from excessive tightening the broken ends are still in there and likely the seats of the carb that these close against are damaged.

Bogie
 
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