Timing

[Hugh Mongus]

I went to Sears today and picked up an advance timing light. I turned the dial to 36 degrees, had my wife press the gas and hold it at 3000 rpms, and set the timing to 0 degrees. This left me with around 18-19 degrees initial timing. Since the advertised timing for a 350 is between 8-12 degrees, should this tell me anything?

I have no idea what's inside the engine. It has been idling rough, idling rich, and fouling plugs in a couple of cylinders. It runs great, but gets poor fuel economy.

[LONGHAIR]

If you assume that the distributor is fully advanced @3000 RPM, it means that you are only getting about 17º of centrifugal timing. It should be 20º. So, either you are not getting all of the advance by 3000, or the centrifugal advance is not advancing enough in general.

You are only a few degrees off, but it would be nice to find them.

This statement confuses me though?

"It has been idling rough, idling rich, and fouling plugs in a couple of cylinders. It runs great, but gets poor fuel economy."


How can it run great, when it idles rough, rich, and fouls plugs?

[Hugh Mongus]

Originally Posted by LONGHAIR

How can it run great, when it idles rough, rich, and fouls plugs?

It just does. It idles rough and blows dark smoke at idle in park or waiting at a light, but when I step in it cruising around it takes off. I'm guessing if I can work out all the gremlins it would run extremely well. However, I am about to the end of my rope trying to make it run correctly. A new crate engine is starting to look really good.

[cool68]

post some pics of motor here. did you disonnect vacuum line from distributor to carb and block off line? seems that 3000 is on the high side for setting timing. need to be looking at carb - fuel delivery problems to figure out dark smoke, etc.

[Hugh Mongus]

I disconnected the vacuum and plugged it. I have also adjusted the idle screws many times using a vacuum gauge. I initially started with 12 inches of vacuum at the manifold and now have 15 inches. I bought a new set of plugs today I will install them tomorrow. I am going to gap them at .035 instead of .045 this time to see if any foul. I also ordered a calibration kit for my carb. It should be here Wednesday.

[ole dollor]

it sounds like your carb is running rich. once you kit it and make sure your float is ok you should be able to see a difference in the idle and black smoke coming out the tail pipe .. good luck

[BMERDOC]

You gotta slow down. I've been around for the last couple of your threads and you ARE making improvements. A crate motor isn't the answer. You ain't gonna like it when I say this but your knowledge is the limiting factor. Please don't be offended by that statement. It is what it is. I work on BMWs for a living and those idiots introduce some new and overly-complicated B.S. every couple of years. I have to relearn every time they do that and it puts a dent in my pay check. It can get frustrating but you can solve it. Even if it comes down to installing a new distributor and carb you will end up figuring this out. Slow down, relax and take your time. Its not the end of the world. I'll stick around and help out when I can.

[Hugh Mongus]

I have thought about buying a Holley if this calibration kit doesn't fix my idle issue. The only thing I have found that I can change at idle with the calibration kit are the springs. So, I don't have much optimism. I am going to spray some carb cleaner in the idle screw holes tomorrow followed with a shot of air. I thought it could be possible that I have some junk in there since I had an issue with trash in my gas tank.

I appreciate the help.

[Hugh Mongus]

I made more progress last night. I changed out all the plugs again with a hotter plug this time (R45TS vice R43TS). I also removed the top of the carb and set the floats. They weren't quite right. I removed the IMSs shot some carb cleaner in the holes and blasted them with air. Then I set the IMSs again and got my manifold vacuum up to 17 inches. It doesn't seem to be idling as rich as before, but I'm not convinced it is where it needs to be either. Hopefully the snow and ice will melt off today, and I can get it out tomorrow. Then I can check the plugs again.

[geezer#99]

What did you do for a fuel regulator?

[Hugh Mongus]

I'm still using the same one I bought last week. I have it set at its max setting of 5.5psi, but is only giving 4psi of fuel pressure. It seems to be working fine at that setting. I will probably buy a better one later.

I am still kicking around the idea of ditching the Edelbrock for a Holley. I am just waiting for the calibration kit I bought to get here. I will mess with that, and if I can iron out this rich idle issue I will probably buy a Holley.

[Hugh Mongus]

Originally Posted by BMERDOC

You gotta slow down. I've been around for the last couple of your threads and you ARE making improvements. A crate motor isn't the answer. You ain't gonna like it when I say this but your knowledge is the limiting factor. Please don't be offended by that statement. It is what it is. I work on BMWs for a living and those idiots introduce some new and overly-complicated B.S. every couple of years. I have to relearn every time they do that and it puts a dent in my pay check. It can get frustrating but you can solve it. Even if it comes down to installing a new distributor and carb you will end up figuring this out. Slow down, relax and take your time. Its not the end of the world. I'll stick around and help out when I can.

No offense taken. If I knew what I was doing I wouldn't be asking so many questions.

I know what you're saying about BMWs. I had a 550. I got rid of it. Once the warranty ran out it seemed to have a new issues weekly. My favorite was the time I was out on the interstate and this picture of a car on a lift popped up on I-drive with a nice message saying "Driving any further is impossible". I drove it the rest of the way home and parked it. The next morning I got in it to go to work and the error was gone.

[steelhorse]

BMERDOC I am a master tech at an independent shop and at least you only have to figure out one make of cars BS. Sometimes I want to whoop up on an automotive engineer.

[jmorri34]

Originally Posted by Hugh Mongus

I have thought about buying a Holley if this calibration kit doesn't fix my idle issue. The only thing I have found that I can change at idle with the calibration kit are the springs. So, I don't have much optimism. I am going to spray some carb cleaner in the idle screw holes tomorrow followed with a shot of air. I thought it could be possible that I have some junk in there since I had an issue with trash in my gas tank.

I appreciate the help.

Did you go to the Edelbrock tech page and go to the graph for your particular Carburetor. I posted on one of your other links about changing the rod and jet settings according to what your carburetor wants. you can richen or lean the carb up by just changing the rods by only loosening 2 bolts. They also tell you which combination to use on the cruise mode or power mode without affecting the other. If you hav'nt done this you will be chasing your tail, its a vital part of tuning an Edelbrock and very simple to do. Just my advice

[Hugh Mongus]

Originally Posted by jmorri34

Did you go to the Edelbrock tech page and go to the graph for your particular Carburetor. I posted on one of your other links about changing the rod and jet settings according to what your carburetor wants. you can richen or lean the carb up by just changing the rods by only loosening 2 bolts. They also tell you which combination to use on the cruise mode or power mode without affecting the other. If you hav'nt done this you will be chasing your tail, its a vital part of tuning an Edelbrock and very simple to do. Just my advice

I have not yet. I ordered the calibration kit so that I can. They don't stock these kits locally. I should have it tomorrow. So, I will be changing the step-up springs first.

I only have an issue at idle. I read the metering rods and jets have no part in the idle mixture. Although, I have no experience with this personally.

I believe it was #3 calibration combination on the chart I was going to try first. If this leans it out too much I will work my way back the other direction a little at a time.

[jmorri34]

Originally Posted by Hugh Mongus

I have not yet. I ordered the calibration kit so that I can. They don't stock these kits locally. I should have it tomorrow. So, I will be changing the step-up springs first.

I only have an issue at idle. I read the metering rods and jets have no part in the idle mixture. Although, I have no experience with this personally.

I believe it was #3 calibration combination on the chart I was going to try first. If this leans it out too much I will work my way back the other direction a little at a time.

That's false, it all has to be right in order for the Carb as a whole to work right. I know from first hand experience working with these two things help in the whole process as I have been working with them myself and have been working on the same problem as you and it is frustrating to say the least Just keep creeping up on it and it will get better too, I know exactly what you are feeling lol

[geezer#99]

If it runs rich at idle, look in the carb while it's idling. You shouldn't hear or see any fuel at all.

[piecesparts]

When I worked on getting my Edelbrock AVS carb set, I took the time to figure out what I had for primary and secondary jets. They are marked on the top of the jets and you can read the size with a magnifying glass. The needles are also marked on their sides, so you can read their sizes. Remember that the needles have two sizes for cruise and power modes. If you take the primary jet size that you have and subtract the sizes of the needles that you have, then you know in thousandths what size orfices or what size that flow paths for fuel that you have. Adjustments of sizes that you would need to get a single or more steps change is easier to figure if you have a base line.

EXAMPLE: .100 jet minus a 4575 needle will give you .55 for cruise and .25 for power. This is just an example. My guess is your primary jet is more like a.094 or a.098 size and the secondary jet is .100 size. I made up a graph and laminated it, with all of the different sizes of needles and jets offered by Edelbrock, so that I now have it in my carb tool kit and that along with a large selection of needles, jets, and springs, I can hit just about any level of flow through the carb.

Adjusting the springs for different levels of vacuum response and also changing the stroke of the accelerator pump gives an impact to acceleration and response to the way the engine transitions from the cruise mode ot he power mode. Many people complain about the Edelbrock and Carter AFB style carbs and how they seem to bog on the transition. Believe me, that can be adjusted out of the carb and it will serve you well.

See attached for the selection of nets, springs and needle sizes avialable. I went to my local auto parts outlet that supplied carb parts or Summit Racing and ordered the needles and jets seperately, so that I could get what I wanted and not what is prepacked for the novice.

http://www.edelbrock.com/automotive_...alibrate.shtml

[jmorri34]

Originally Posted by piecesparts

When I worked on getting my Edelbrock AVS carb set, I took the time to figure out what I had for primary and secondary jets. They are marked on the top of the jets and you can read the size with a magnifying glass. The needles are also marked on their sides, so you can read their sizes. Remember that the needles have two sizes for cruise and power modes. If you take the primary jet size that you have and subtract the sizes of the needles that you have, then you know in thousandths what size orfices or what size that flow paths for fuel that you have. Adjustments of sizes that you would need to get a single or more steps change is easier to figure if you have a base line.

EXAMPLE: .100 jet minus a 4575 needle will give you .55 for cruise and .25 for power. This is just an example. My guess is your primary jet is more like a.094 or a.098 size and the secondary jet is .100 size. I made up a graph and laminated it, with all of the different sizes of needles and jets offered by Edelbrock, so that I now have it in my carb tool kit and that along with a large selection of needles, jets, and springs, I can hit just about any level of flow through the carb.

Adjusting the springs for different levels of vacuum response and also changing the stroke of the accelerator pump gives an impact to acceleration and response to the way the engine transitions from the cruise mode ot he power mode. Many people complain about the Edelbrock and Carter AFB style carbs and how they seem to bog on the transition. Believe me, that can be adjusted out of the carb and it will serve you well.

See attached for the selection of nets, springs and needle sizes avialable. I went to my local auto parts outlet that supplied carb parts or Summit Racing and ordered the needles and jets seperately, so that I could get what I wanted and not what is prepacked for the novice.

http://www.edelbrock.com/automotive_...alibrate.shtml

X2!! I am a die hard holley fan but the more I mess with this Carb the more I am liking it for street vehicles, it is very user friendly. If you use this formula he's stating or use the graph I was telling you about you will really be able to fine tune it. I am still working on mine right now but creeping up on it.

[Hugh Mongus]

I noticed something new this morning. When I fired up the truck this morning to leave for work there was a loud clatter like the lifters were ticking. It lasted for a few seconds as if it was waiting for the oil to cycle through the engine then went away. It hasn't done that before. Could my timing change cause this?

[geezer#99]

Just the lifters pumping up. Timing won't do that.
Do you use a block heater?

[Hugh Mongus]

No, but it has been cold here this week. Should I be concerned about wear when it does this? The oil pressure is reading normal and I check the oil before I drive it, so I know it isn't low.

[geezer#99]

Shouldn't hurt it!
You should hear them when they start at 40 below.

[piecesparts]

What are you running for oil? If you are a little heavy on weight, there is some time involved in the oil building up to pressure.

[cool68]

low gas octane can affect engine knock/clatter