harald

me and some of the guys on this site have been looking for this problem for weeks, not being able to find the problem. my 69 302 would die down as soon as i hit any gear, a C4 as well by the way.

think about this for a minute.your carb has got vacuum secondaries, i suppose. it might very well be that with the new cam your vacuum setting is changed and that these vacuum secondaries open too fast, stay open or open too slow.

i had more or less the exact same setup as you, but with a holley 600. mine stayed open in and thus, as soon as i put it in gear, the vacuum dropped and the engine flooded with gas and died down. a simple trick to check if this is your problem is too unhook the vacuum secondaries linkage from the vacuum bowl running down to the secondarie butterflies.

right hand side on my 600, dunno what it'll be on yours but i guess the same. takes a minute, solved weeks of agony and stress.....


let us know if that was the problem, will you?

6mustang6

like i said, the stock torque convertor might not be able to handle it. When i put in a big cam in my 350, it would stall at idle, put in the new torque convertor and it went away.

valley firearms

I will try these ideas. I was going to go outside and work on her but it just started pouring rain![:@] I'm going anyway.

valley firearms

Well, I just came in out of the rain. I took the valve covers off and checked all the rockers. One was a little looser than the rest. So I followed the Comp cams instructions and readjusted it. I then messed with the timing a little. I advanced it about 20deg and she runs fine now. She idles in all gears. I will take her for a spin tomorrow. When I aligned the timing marks on the gears(during install) I got it as close to mating the marks as possible. With the gear drive, it didn't seem to align exactly like a timing chain set up. This may also be a factor in my timing. I may pick the distributor up and move it over one tooth tomorrow. This may take it too far out but I'll find out. Right now I'm all the way up against the thermostat housing with the vacuum advance diaphram housing and can't move it any more in that direction. I remeber doing that with my other mustangs 25 or so years ago. Wish me luck and chime in please.

harald

yep, had that problem too (had quite a few hick-ups on initial startup, come to think of it), and mine runs great now on 14 degrees advanced. but it should run 6-8 in the book. i guess the books aren't always spot on if you take into account the various factors that affect these things like octane and such. also, best way of course is to get a digital timing light that tells you the advance itself, as apparently the rubber insulator on the crank pulley sometimes rots out and the timing marks get moved away from their original position...
(i didn't know that either but that's what i found out during those weeks of agony i mentioned earlier)

good luck and lots of fun!

6mustang6

Mine does the exact same thing. Mine wont run at all at 6 degrees. It makes we wonder if my timing chain is slack.

Soaring

It is not designed to run at 6 degrees BTDC. It is designed to run at 17 or more. Run the dizzy clockwise to as far as you can turn it, and see if you get a ping. If you do, then back off a few degrees. If you can't turn the dizzy far enough clockwise, then take it out and slip it one gear more so that you can achieve max until you get a ping, then back off a few degrees for optimum performance from your engine. After you get it there, then replace the points with electronic ignition.

harald

this could be a really stupid question, but why does every manual i read say 6° then? even in the comp cams tech section they say run the standard advance, since the cams are ground advanced themselves?

Soaring

I am really sorry. I was thinking about the points setting of 0.017. Of course, 6-8 degrees BTDC is the right ball park setting for the timing.

67_FASTBACK

dont know, but bigger cams are supposed to run rough at low rpms. they are meant for high rpm & high horsepower. that may be the reason. just gotta get used to it or downgrade to a smaller cam. you may be speaking of a different problem and i am missunderstanging tho, srry. good luck