My advice to you is to put theengine back to as close to stock as possible. Put a single barrel carb and intake back on. Reconnect all the factory hoses to the carb in the right places.

The rough running and inability to put the timing at the right spot might all be carb related. The Holley 390 is a carb that has an infinite amount of tune-abliity and requires some expertise and patience to set up right. It is very rarely a bolt-on-and-go installation.

I suspect that you have mixture problems at idle causing the rough running and that your timing is either too far advanced or too far retarded because you need to also adjust the idle speed screw on the carb while you adjust the timing.

Up to a point, advancing the timing will make the engine speed rise. As the timing is advanced and the engine speed increases, you must lower the idle speed using the idle speed screw on the carb so the engine idles at the right RPM. If the timing is advanced and the idle speed is not lowered via the carb, then the engine RPM can increase to the point where the mechanical advance kicks in and makes the engine run even faster. This would appear as a rapid and uncontrolled increas in idle RPM as the timing was advanced.

I recommend putting the stock carb back on and trying to get the idle timing and idle RPM back to stock specs.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

--Reed

I don't know if it was strictly carb related cause the overheating issue was happening with the old single barrel before I put this 390CFM Holley on, I have adjusted it like crazy and and the hoses are hooked up correctly as far as I know. a two weeks ago I had a friend of mine overlook it and he set them up correctly.

I've been running with this CARB for quite a while before the engine rebuild and the engine was OK, but still shaky since it was like that before. It wasn't until the engine rebuild that my overheating problem went ridiculous. I did adjust it to be richer and tweaked it in different way,

Also The reason I moved to this carb was because the old one was REALLY bad, it was always breaking down, giving WORSE mileage than the 4 barrel (if you can beleive that) and had gone through 2! rebuilds by a well known carb shop in SAC (It failed under warranty twice!) I just went with a new one. but is this 390 CFM TOO much carb for my engine? Either way, I still have the old headers, but if I would HAVE to downgrade, it would roll back to a 2 barrel since I gave away the single barrel as soon as the car was running well enough on the 390.

Anyways, now that the problem is closer to getting solved, I think it was a combination of little things.

Radiator was pulled out and flushed
Timing was set
Old distributor upgraded to electronic
Carb adjustment and Hoses setup properly.
Valve adjustment
Thermostat was swapped from 195 to a 180
(Soon) Fan shroud
(soon) Bigger fan to "19

All this was in the past 2 weeks, and the problem's been going away. I just want to make sure it doesn't happen again or comes back with a vengance.

My point was to try and make diagnosis as simple as posisble by returning the engine to as close to stock as possible. There have ben a number of modifications to the engine, including a rebuild of unknown quality. You say you are still learning how to work on old cars, which is fine, but even experts have difficulty diagnosing engine problems when multiple vaiables like carbs, distributors, ignition systems, etc… are being modified simultaneously. By installing a number of modifications simultaneously , especially when you are not 100% sure of what the effects of each modification will do, you are making troubleshooting a nightmare on the engine.

If your engine is rebuilt with a stock head and a stock cam, then the 390 may very well be too large of a carb for it.

If the stumbling happens when the carb is cold, verify your choke is working correctly.

The open element air cleaner certainly will not help overheating problems.

Going to oversize and aftermarket components is really treating symptoms and not the underlying problem.

Have you installed a mechanical temp gauge to verify the engine temperature while the engine is running?

Without being able to put my hands on the engine it is very hard to diagnose this kind of problem.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

--reed

thanks for the tips, I have been doing mods one by one it just seems simultaneously cause of the quick pace i went through them. But I am being careful as to what changes are being made every time.

I had no idea about the open air cleaner, the car came with a huge ole version of that an I swapped it our cause the old was was ugly and rusted, I think it came from an old pickup truck.

I have a mechanical temp gauge I bought and will try that too, I'll see if it matches what the dash says.

Try to find a stock style closed element air cleaner that will fit on the carb and let the hood close. Then use a bit of dryer hose and some roof gutter piece to fabricate a cold air intake system that draws cool air from up by the grill into the air cleaner. Otherwise the engine is sucking hot underhood air which doesn't help with power or economy.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

OK we just finished it. I think we're done. I don't want to jinx it but wow! the fan and shroud helped a ton!

While I was removing the radiator I found out that the last mechanic took out the thermostat, so I'll have to add one soon for the coming winter, (What temp thermostat is recommended anyways? 180? )

We learned a few mistakes too.


The fan was touching the rad, but luckily we heard it before it got bad, and don't yell at me yet! the car never left the driveway with the fan this close. this was just while idling and teasting the fan, funny how when we spun it it didn't touch, but once the motor got running the flex fan was true to it's name and flex towards the rad just a bit.

Local parts store didn't have the 1and3/4 fan spacer needed to fix our problem, so we made our own due to time constraints and it's just a spacer anyways.


and here's a vid of what it sounds like, but the phone i recored it with has pretty bad sound, what's funny was that after the fan install, the engine was soo quiet!! You can barely hear it in the video, in fact all you hear is the fan.
http://vid1009.photobucket.com/albums/a ... EO0045.mp4
It worried me but after running the on the freeway for about 10 minutes and 10 on the streets, the temp stayed in the lows. Tomorrow I'm taking it back to work and seeing how it handles the 30 mile drive to Folsom and back. I hope it's hot, but with my luck, it'll rain. Either we'll see if the problem's fixed.

I still want to do the cold air intake thing reed said, but with the shroud i noticed that now the air filter gets a lot of air from the flex fan directed towards it. It never did that before without the shroud.

Add a thermostat ASAP... it is a key part of the cooling system.
Sounds funny but having no thermostat can contribute to overheating problems.
A 180 is a good place to start.
DD

As above ^^^^ And get some antifrezze mixed in there. I believe that about a 20%-30% AF mix gives best cooling.... it's easy to research that.

OK, so to clarify, the overheating issues is pretty well going away? Please update us after the test drive. You're not the first to experience 'the curse of the flex fan'... LOL

So now the main issue is a rough idle, and erratic advance? If so, perhaps it would be good to start new thread, with the symptoms, engine pix and such repeated. This thread has become hard to follow, IMO.

Sorry it's been hard to follow and keep a straight line in this thread as it seems that I keep moving on to the next thing without saying what I've done or what's the status. It's been a while since I've been on a forum so I keep forgetting etiquette.

-- Yes I think the overheating issues has gone well away, I just drove it to work today and the temperature has not risen above 1/4, it remained way down there but it was a chilly morning so I'll try again in the afternoon and maybe take it to farther. For a few seconds I heard a faint "bbrrr quick flapping" noise while on the highway, (i'm paranoid right now with that flex fan) but didn't notice anything when I pulled into work and the faint sound went away after a few seconds, so I'm going to take it easy until I'm confident with the car.

-- I might not start a new thread involving the rough idle until I finish tuning the car, I still need to trim some hoses and clean up the wires as they are all over the place. And spark plugs, I got some NGKs for this engine so we'l see how it goes.

-- so on my list are proper coolant and a thermostat, got it.