Some new Clues! - Finally figuring this out!!!! LOOK!

[Anonymous]

OK, so after reading about the timing and all the related issues, I decided to try a few things...


1. I pulled both air/fuel mixture screws and they are fine, clean and not bent, although one was 1 1/2 turns out and one was 2 1/4 turns out, this is not good, since they should be equal. I set them both to 1 1/2 turns.

2. From a cold startup here are the tuning numbers, vacume 16inches, idle 1600 timing 35 degrees (dialed back to 0 on the light!)

As it warmed up this fell down to 1000 rpms, 12 inches of vacume, and 25 degrees in the timing light. Once the choke was completely open it did it's usual attempt to stall and the vacume dropped to 6 and then almost 0... but it holds a vibrating and steady needle at 16 until it warms up.
Then if I can get it going a bit, it sits shaky at 12 inches.

I had at this point the PCV line hooked into the base of the 2300. The vacume advance hooked into the "Ported" source at the carb on the metering block. and the gauge on the tree.

First I decided to pull the vacume gauge off the intake tree on the manifold and hook the advance line from the carb striaght up to the intake manifold tree.
When I pulled the line the enigne rpms increased and it smoothed out just being open.
Then I hooked the advance line up and the rpms increased more, so I decided to back the curb idle down now with the advance hooked to full manifold, I got the rpms down to 800 with no missing or stumble, a little shaky, but nothing like before, and it idles really much better in the 800 to 900 range than it did hooked to ported source.
I hooked the gauge up to the "Ported" source and get a 0 reading at idle, I get a 7-10 inches reading at throttle from 1200-1600 rpms... on that ported source of vacume from the metering block.

with the advance line on the dizzy hooked to the ported source I measure 16 degrees initial with that line pulling no vacume, if you pull the line it has no effect on the timing. Like I posted before.

With the advance line hooked to the intake manifold getting full vacume I get a reading of about 30 degrees at idle running at 800 rpms (shaky)... but if I pull the vacume line to set the timing it drops the engine so low it dies. Also the timing at this rpm range is a little jumpy, meaning the mark jumps a bit, and it is hard to get a reading on, but that may be from what sounds like the timing being advanced too far with this much vacume pulling on the diaphram. I need to back it down from here and adjust the idle if I am going to run with full vacume. but I want some opinions on this information first...


so my questions are?

is the ported source supposed to have 0 vacume at idle? if so then that would have no affect on the timing.
is is better to run with ported vacume? Full vacume? or no vacume?
how can I set this up to be correct?

Thanks

 

[Anonymous]

So I was reading through some books to shed some light, and I decided to start from ground zero, I pulled all the vacume lines and plugged everything.

Dropped the rpms to 800 even, set the timing to 10 degrees initial.
(It runs here, somewhat shaky, and stumbles but runs.)

I also checked the advance at this point all plugged, set at 10 degrees, running at 800 then slowly bring the throttle in and it moves almost imediately, going up to 20 degrees running at 2000 rpms.

I let it run like that for a few, then pulled the gauge and hooked the advance back up to the full mainfold and it rises the rpms to 1200 and takes the timng to 30 (dialed back to 0)

FYI!

what to do now!

Also I have been rading some old posts on timing and they talk about different spring rates for auto and manual trannies, this distributor was on my C4 auto prior to install on this new rebuild, it is a 79 200 DSII dizzy I am going to pull the cap and see if I can find any numbers on the internals or see what is in there...

is this system load-o-matic or what, do I need the timing all in at idle or am I suposed to use the ported source or what I am getting confused I have too much information for too many distributors and not sure how mine applies?

Thanks


Holley 2300
MSD 6A
DSII dizzy
Platinum plugs gapped to 50
helicore wires
Petronix coil

Jimbo

 

[CobraSix]

The ported vacuum should read 0 below like 1000-1200 RPM. 20* at 2000 RPM isn't bad. remember, you should be at full advance (34-38*) at 3000 or so RPM.

If you opened up the manvacuum port and RPMs you are running rich at idle. that could cause the hard idling. Maybe reset your idle screws.

DS2 is not like the loadomatic as far as I know. I'm runnign my DS2 right from the ported vacuum on my 1100 and it works nicely. However, wondering if the ported vacuum on the 2300 pulls more vacuum then the 1100. maybe the diaphgram isn't working right or adjusted right. Have you tried running your car without the vacuum advance and just setting initial to like 16-18*BTDC?

Slade

 

[Anonymous]

OK, so I set the timing to 16 initial, plugged the vacume ports, and set the idle to 800, adjusting each idle screw 1/4 at a time, things are shaky screw them in till things get rough and back them out 1/4 turn, things are still shaky set like this.

It is idling at 800, timing 16 degrees, this puts the vacume level at 10-9 inches, and the engine is shaky, this is where I was before, since if you go on the premise that there is no vacume from the timed port at idle, then it would always be at 16 degrees and with this crappy vacume reading?

I can back the screws out, get the idle to smooth a little causing the vacume to rise to around 12 inches at best, but however set at this setting the 8.5 power valve could be opening when the idle vacume hits 9 or so, it seems to surge at this speed and does not idle well?

The best idle I have had so far is with the advance hooked to manifold, getting vacume at idle, although that would be nice, considering the timing is at 30 with the idle at 1200?

Something is not right in denmark.

Jimbo

 

[Anonymous]

OK, so again one more time out on the engine,

now here are some interesting numbers.

Set the rpms to 800, adjusted the float back up a little from yesterday, set the fuel mixure till I got as smooth a run as possible and tried to get it to stop surging at 800, I got it a lot better. Also when I pull the vacume line it no longer rises in rpms, now it just sputters.

so I checked the mechanical advance with the vacume line plugged. At 800 that equals 16 degrees, 2000 = 20 degrees, 2500 = 25 degrees and so forth to about 30 total was the best I could get around 2900 rpms. my tach only goes that high for a six.

when you hook up the ported vacume on the carb, things change drastically.... initial is still 16, 2000 rpms and that is 30, 2500 rpms and that is 45 total... sounds like too much.

should I try to run it without for a few and see how that is, I can always bump the 16 to 20 and get some more mechanical on the top end...?


Jimbo

 

[CobraSix]

I'd bump the 16 to 18-20 and see how it runs for a few days.

It sounds like you may need a new diaghram on the vacuum advance side. I'm not sure about what that involves. Never had to do it. HOpe that helps.

Slade

 

[Anonymous]

OH YEAH!!!

seriously woke this engine up...

set the timing to 16 and idle at 800, from getting the kinks out with the ratio and float level the idle is lopey, but sounds about right for the 270 cam, and it it even, no surge, no stalls....


RUNS LIKE A CHAMP... finally have throttle above 3000 rpms, runs nicely right up to 4000... and stays cool too.

It is not as peppy as it was before, but it does not hesitate or stall, climbs the hills nice too. I think the low vacume being at 12 degrees might be giving me some of the trouble, if this is where the engine is going to sit, I may need to investigate going back to another power valve or something of the like, but for the next couple of days I am going to drive it like this and see how it reacts to no vacume.

I may want to get lighter springs in the dizzy, or even pull back the vacume advance.
but for the sake of running, right now it runs like a champ!

 

[ricksmol]

Glad to hear that things finally begin to go your way. It takes a lot of fiddling with these things before they get to where you want them to run. I know I've been there!
Keep up the good work and enjoy the car.

Rick

 

[Anonymous]

NOPE! Not there yet...

I guess I did not drive it far enough earlier or I did not get the same results because I did not give it a highway drive.

1. idles OK, at 800, but still rises and falls, chugs smooth a couple of turns then revs down chugga chugga, then up and smooth for a turn or so...
2. No power with this setup, throttle is good up through the 3000 range, but is relatively flat, and I have to give it some go to get response and it tends to buck a little...
3. still wants to stall after coming off the highway, rpms drop and drop with the clutch in, and if you give it a little gas you get the squeal again? same as before.
4. the engine bucks and does not run smooth at power, on the highway it was a little hesitant running in 5th gear at 2300 rpms, little throttle hesitates...? lots of throttle gets a response.

sounds like I am back to square one again...

It does run cooler, but still gets hot in the high rpm ranges, then cools down if I am nice to it, and it is 34 degrees here today...

 

[Anonymous]

I think its time to start from square one again

Pull the carb, adapter and intake off and make a thicker intake gasket and get a thicker carb to adapter gasket from youre local auto parts store. Get some gasket material from Mr Gasket to make the adapter to intake manifold gasket. The stock POS baseplate gasket that Holley sends with the carb should just be thrown in the trash...it has little or no value IMO

I say its a vacuum leak and has little to do with the timing Chugging, high idle rpm's and inconsistant engine idle rpms are all indicators of a bad vacuum leak.

Clean the carb out good with some carb cleaner and reinstall the stock jets and power valve. Flush all the ports in there with a large dose of carb cleaner. Pull the needle and seat and double check that there is no junk in there.

Set the base timing to 12 degrees initial at 1,000 rpms and hopefully it will be around 38 degrees total around 3000-3200 rpms. A 270-272h cam will not idle much under 800-900 rpms so forget trying to get it to idle at 6,7 or 800 rpms like a regular cam will.

Dont lose hope....You'll get it all sorted out!!!

EDIT

Answer this question? I recall you finding a inline? pcv valve IIRC....What was the application for it?? Ford inline 6 or V8 or somthing different?? You cant really interchange a V8 pcv valve for a I6 or visa versa.

The valve is basically a controlled vacuum leak and if you look at the bottoms of the valves for the different applications you will see what I'm talking about.
The hole for our I 6's is small vs a much larger hole for a V8. The check valve (inside the pcv valve) also has different depth setting to it, depending on application and how much air (vacuum) it has to flow. If you just picked up a inline valve off the shelf and its not for your specific (or I6) application that is probably most of your problem.

Later,

Doug

 

[Anonymous]

I think you may need to go back and run the distributor hooked up to manifold vacuum. You got a better idle quality at that setting. Back off the initial timing to the +/- 10 deg range as you had it before. If your idle still jumps to 1200 rpm, you can back it off. Ported source vacuum was one of the ways to retard timing at idle in order to raise combustion temps and reduce emissions.

I like to map out the timing and see how much of advance is at increments of 500 rpm. Do it with the vac advance connected and disconnected to see how much cnetrifugal and vacuum advance is contributing. You'll probably notice your engine temp rising as you go through this exercise with the vac advance disconnected. Retarded timing causes overheating.

The flat response that you are getting in 5th gear is due to retarded timing. Since you disconnected the vac advance, you are running less timing than you would normally get. The rpm's drop significantly in the overdrive, and you do not have enough centrifugal advance under these conditions. Engines can take more advance at part throttle highway speeds up into the 45 deg range. Ported source vac advance contributes some advance under these part throttle conditions. Listen for the pinging and back off timing if necessary. As you noted, you may have to change weights, springs and vacuum cans to get the desired advance map that works for your engine.

 

[Anonymous]

Doug,

that is my next course of action, for now I have re-hooked the vacume advance and set the timing to 10 degrees initial. Then I set the idle at 900-1000 ish and seems to like this idle for now.

I will get some gasket material and make my own gaskets, then I will seal them with Ultra Copper and be done with it.
(That will have towait till next weekend)


As for the PCV question, you are right on, I have no idea what valve I got I just got one inline that was close to the same number on the one for this engine, IIRC they were something like N-864 for the lookup, and N-B864 for this one? or something like that, basically it was a close match, but it could be way off...

However because of the way I set this up, I do not necessarily need an inline valve, I ran a length of 5/8 heater hose off the mopar cap and the valve seats completely inside that, so I could use a stock valve, if it would work laying on it's side, that is the only thing I am unsure of, since it seems like gravity should play a role in the use of the PCV valve? then I ran a length of hose to the carb base from the valve like normal, seems to work fine, although I get a little oil discharge from the base of the mopar cap? seems to seap out of the grommet around the base, nothing bad, just a little run once in a while?
(This was not the best of setups, but was the only thing I got to work it is sealed up tight and does seem to work.... but the valve could be wrong YES!)

 

[Lazy JW]

Try temporarily unhooking the PCV line and plug the manifold, thereby eliminating it as a trouble source. Manifold vacuum applied to the distributor should help as that tends to raise the idle speed, which means you would need to close the throttle more and this should increase the vacuum making the idle circuit more sensitive. Good Luck!
Joe

 

[addo]

A quirk I have noticed on a couple of rebuilt ignitions is that the vacuum advance seems too extreme. This I attribute to different combustion properties of the newer fuels. The net result is "damned if you do, damned if you don't..." You set it up to run great and then as the motor warms, it all comes unstuck. Oh dear. Especially overrunning (like coasting downhill or to a stop) - it'll pop and ping and carry on.

Haven't gone looking for a smaller - and hence stiffer - diaphragm (though they may be "out there"), but instead chose another option: Use a thermal switch so as the motor warms, the vacuum eventually becomes unavailable. I have also heard of people slotting or modifying the actuator arm on the diaphragm so that the effective travel is less.

One of the best pieces of advice I read on pinging was to retard two degrees beyond that which caused audible pinging, for safety of the motor.

Anyhow, possibly a distraction in the topic, but another opinion!

Adam.

 

[Anonymous]

Mopar one?? I thought you found a Autolite cap like mine?? They are on ebay all the time.

Anyway,
You cant run a pcv valve on its side or upside down You are right...the "weight" is calibrated with gravity on its side....

Heres one on ebay that is a "twist on" style that you could use with the proper grommet & valve,

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 2447123398

Later,

Doug

 

[Anonymous]

My 65 Lincoln has a factory PCV laying on its side. I think some of the valves have a spring inside rather than relying solely on gravity. I do know that the valve for my 65 Lincoln was getting hard to find last time I bought one 10 yrs ago.

 

[gtm1086]

I agree with Doug. I think you are fighting a vacuum leak. Also when you are setting your idle is that in gear or in neutral. If in neutral 1000/1200 rpm should be just fine with the cam you are running. As long as the engine doesn't want to diesel on you when you shut it off it should be fine.

 

[Anonymous]

My 65 Lincoln has a factory PCV laying on its side. I think some of the valves have a spring inside rather than relying solely on gravity. I do know that the valve for my 65 Lincoln was getting hard to find last time I bought one 10 yrs ago.

Yep,
I've seen some of those that were designed to do that!

Jimbo....where ya at??

Later,

Doug

 

[Anonymous]

Sorry everyone, I have been out of the loop for a little while, feeling under the really cold weather here lately, and too much christmas shopping to really work on the Mustang...

I bought some gasket material this morning, I am going to take it apart over the holidays, just too much going on right now to get into it...

it has been running pretty good lately, I was able to get the idle and other adjustments under control last time I tuned it, it idles very nicely at 1000 rpms with no surge and no stalling (at least in the last week it has been OK...)


According to the guys at Schneider Racing Cams this engine should idle at 700 for a manual with this cam accroding to them, I know you guys are saying 1000, but they say differently... I agree with the vacume leak, and I am going to make sure I do not get one on the re-assembly next week.

I will post the findings once I take care of this....


Thanks


Jimbo

 

[CobraSix]

You should be able to idle that low. I know my 260 Comp cam has no problems idling to as low as 550, though it likes 700 RPM on warm days, and 800 on cold days. You cam specs are that much different to make you have to idle at 1000 RPM.

Slade