Slow to start... 289 with Autolite 4100

if standard transmission, one thing that causes this is not putting the clutch in when you try to start it which can sometimes result in a slow engine tunover. Otherwise a possible vacuum leak somewhere, or varnish in the engine can cause problems like you describe, along with other things like timing and so on

These carbs had some issues with the power valve.... even a very slight backfire into the intake could perforate the diaphragm allowing the float bowl to drain into the intake manifold.... acted like a flooded motor on restart.

-- Jim Warman snipped-for-privacy@telusplanet.net

snipped-for-privacy@therogers.us (MichaelRogers) wrote

The first thing you need to do is put in a Pertronix Ignitor points replacment kit. I'd go with the Ignitor II, which at low rpm gives you spark for 30 degrees of crank rotation. A hot coil -- 35,000 volts or more -- would be good too. Pertronix Flamethrowers are finished in black so they don't stand out. Summit has plain black ones too. New plug wires wouldn't hurt either. There are some 8 mm ones out there in black that don't stand out too much. I think MSD makes some. Fresh plugs are nice too.

So now you've got a hot spark, and life will be better all the way around. No big horsepower increases, but much better starting and driveability.

Set your timing with a light. Or you can use a vacuum gauge and advance the dizzie for max vacuum. Or you can drive up a big hill on a hot day in high gear and see if you've got ping; advance the timing until you do, then back it off.

Set the idle mixture screws with a vacuum gauge too. Go for max vacuum.

That's about all the tune-up stuff I know.

Cold starting problems point to the choke and fast idle cam. There are far more knowledgeable people in this NG than me, and you should also join vintage-mustang.com's forum and post there. But I know you can check the choke pretty easy just by taking off the air cleaner when the engine's cold and see if the choke plate is closed. If it's not, then that's the problem. Probably the pull off is stuck. Also, make sure the fast idle cam is working. Jerk on the throttle bell crank like you were stomping on the gas pedal, and see if the cam is catching and holding the throttle open slightly.

Another cold start driveability problem can be if the heat riser ports in the cylinder heads are clogged. You've got to remove the intake manifold to check this, and that's a pretty big job. So I'd save that for last. I'd even try a carb rebuild (or replace with an Edelbrock) first.

Another driveability problem can be a clogged fuel filter. They're cheap and easy to replace, so do it.

So there you have it, lots of superficial advice that's probably all wrong but it will cost you hundreds of dollars to find out! In other words, a Web classic.

LOL. Well, you get what you pay for, right? Seriously though, thanks for all the suggestions. I needed some things to look at and that's what you gave me. A number of people I have spoken to at work also thought I needed to check vacuum and timing, which I can do pretty easily, especially if I use their equipment, lol. Great thing is, it's never hard to find someone willing to help you work on an old 289 ;). Gonna try and hit a few things myself first though.

Thanks again

Michael

I always start with clutch in.... habit I picked up somewhere, guess it's a good thing. I'll also check vacuum and timing... got some tips on that today, though they were pretty insistant that I adjust the points first.

Thanks much for the suggestions

Michael

I've been wondering how that might happen, as that is what I was beginning to think was happening... somehow the bowl seems like it is draining....just couldn't figure out how as I thought I everything was working properly. I'll check the diaphragm...it should be good since i just replaced it during rebuild ...which I think now was last summer, and I have very few miles on it since. Still, worth a look.

Thanks for the tip

Michael

Been a llooonnnnggggg while since I had one of these apart - IIRC, this is the square flange Motorcraft (four equal sized bores) and a flat top - if you're real careful (and real brave), you can run the motor wth the top off the carb.

When you check the power valve, run the car for a few minutes before removing the carb..... allow it to sit for a few minutes more (just taking your time at getting the carb off should suffice). Once you get the power valve cover off, look close for signs of fuel around the vacuum side of the diaphragm - shows up real clear. Upside is that Holley powervalves fit - downside is that, though the MC and Holley jets 'look' identical, the threads and OD are slightly different.

HTH

-- Jim Warman snipped-for-privacy@telusplanet.net

Makes me wonder how I ever used to drive my 289/225 hp with those crappy old stock parts at all....

Back then, those that couldn't afford a CD ignition could always spring 14 bux or so for the dual point breaker conversion kit..... Now that was sad seeing that dropped from the Motorsport catalogue...

-- Jim Warman snipped-for-privacy@telusplanet.net

I hate to recommend something cheap, but have you thought of just checking the floats to see if you need to tweek (adjust) them a little... sometimes its just a little bend that fixes a float problem. Then again just one grain of sand in a needle valve will cause a big problem also.

Personally, I went to the Holley Street Avenger 670cfm and think its the best $350 I've spent on the car.

"MichaelRogers" wrote: I have a '65 Fastback GT with a 289 and a standard autolite 4100 4

"Jim Warman" wrote

Very funny.

One reply would be, that when those points get burned or the cam follower wears out, you DON'T drive it.

All I know is, my kids' '65 Mustang with Ignitor II, Flamethrower coil, and 8 mm wires, and my '70 Cougar with MSD dizzie, coil, and 8.5 mm wires, and a Crane Hi-6R amplifier, are both the same: stomp the gas pedal, crank the starter enough for one crank rotation, and BAM! they're running. It's just a good feeling to know the old heaps will ALWAYS start.

With the Ignitor I available everywhere for $75 or less, why would you NOT want one? Just the savings in points and hassle to replace them is reason enough to do the swap.

I'm willing to try pretty much anything that I understand how to do and has a possibility of fixing it. How would the floats cause this...adjusted so that the bowl drains?

snip

snip

"One crank rotation"? They should start with a single cylinder fire. That is, unless you are a woman. Then, two or three seconds of the engine fighting the starter should suffice.

Huh? One crank rotation = four cylinders with their plugs firing. I'm not able to tell if it's the first, second, third, or fourth cylinder to have its plug fire that actually catches. Since only 90 degrees of crank rotation separate each firing, I think it's close enough to say that the engine starts running at some point in the first crank rotation. If it makes you happy to say it's more like one-quarter of a rotation, or one-half, or three-quarters, then be my guest, make yourself happy.

What being a woman has to do with any of this, I can't guess. Why you saw fit to take some of your free time to post this half-assed zinger, I can't guess that either. If you have a point to make, make it. If you have a joke to make, make it funny. Otherwise, STFU.

180 Out TS 28