Distributor had black spring installed which it is the stoutest of the light springs in the selection as well as the long loop. According to chart it starts to allow mechanical advance at 1400 rpm and adds 2 crank degrees per each 200 additional rpm. So it was mostly doing its job as designed. I was able to give the spring post a twist to add a little more tension. Hopefully this adjustment and perhaps a little lower in park idle rpm will cure the self-increasing idle rpm. Also I knocked back base timing to 12-13 degrees.

After all these adjustments the car is less jumpy when shifting from P to R or D. No more squeaking the tires and drive train clunks in garage, and snapping necks if brake was not applied forcefully enough. It now barks the tires during a 1-2 manual up shift above 4000 rpm. So perhaps it is making more torque now than before, even though it feels slower or more docile now.

Tomorrow I’ll play with secondary springs, and rod her around a little and see if the idle still creeps up. Another test is when making a left turn from our street onto about a 5% uphill grade, and up a ways there a land mark that in the past the Dart can be making 47 mph when passing it. It will be interesting if she will exceed that benchmark after all this super tuning. LOL

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Sounds like you could use a stiffer primary spring to tame the beast unless you have a vacuum leak somewhere.....forget to plug in the vacuum pod? Hopefully cranking the post out all the way will do the trick.

I see your understanding where I was going with lash and when set right will provide a more even compression test.

I like your test results with the plug to check the primary jetting....very cool! That eliminates one more variable....

Those Holley 390's are touchy on the idle mixture screw settings. It is like off and on..... an Edelbrock AVS won't give you the grief the Holley does.

Nice work!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Ted:
[quote]Those Holley 390's are touchy on the idle mixture screw settings. It is like off and on..... an Edelbrock AVS won't give you the grief the Holley does.[/quote]

You are right on the off & on idle mixture screws; way too finicky.

I almost pulled the trigger on a new Edelbrock AVS last week, but my alter piker cheap bastard half has taken control back. This has become a test of determination to make that old 390 work. This not to say after I win over that chunk of pot metal, I won’t just pick up a new AVS… I figure I’m learning something in a fuel injection age, that something is analogous to perfecting buggy whip tricks to get a nag to go faster I fear… What the hell, my grandfather was born in the horse & buggy days, my father a year or two after radio started broadcasting, and me, when cars still had a starter button next to the gas pedal. Maybe it was growing up with depression era family members that kicked the crap out of the axis powers that never gave up or spent an extra dime that has fostered my stubborn streak.

[quote]I see your understanding where I was going with lash and when set right will provide a more even compression test.[/quote]

For some reason this never occurred to me, I just thought that there was a ring problem, not a crappy lash job. I can hear Mrs. Wjajr; “you always think your right, don’t you.â€￾ Translation; you’re an idiot, suffering from headacranialrectitice. Sun rises over [url=http://en.wikipedia.org/wiki/Marblehead,_Massachusetts] Marblehead[/url] once again…


[quote]Nice work!
I like your test results with the plug to check the primary jetting....very cool! That eliminates one more variable....[/quote]

Thanks Ted. I’m beginning to get a more encompassing understanding of these cars. It is safe to say I can write volumes on this subject on what I don’t know.

Bill

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Now that the 13 day plumbing/geo-heat project in the basement has come to an end, Mother Nature changed tactics stopping the rain allowing sun to finally shine, and temperatures have now moved into the low 70’s in the Pine Tree State; I have installed a pair of 49 jets in the old Holley 390 that sat on the bench for two weeks in their package….

Carburetor tuning has resumed today with the installation of 49 jets replacing stock 512 jets. Engine runs more in the lean and ideal zone except when throttle is just cracked open under steady cruise where it runs rich; 0.9volts, and under power valve 0.9 v to 0.7v; per o2 sensor. Most of the rest of the time A/F gage swings between lean and .7 volts. Plug’s electrodes and porcelain are a light tan color; thread portion of plug exposed to combustion chamber is no longer dusty black, but gray-tan. Exhaust pipes are trending to gray from dusty black.

Engine is not as spunky as it was with tighter lash, and does not seem to pull as hard when into the secondaries. During a 12 mile test run cruising up to 3000 rpm, with a lot of grade changes I may have heard some faint knocking, but not sure hard to hear with top down. I also leaned out the idle mixture a bit more.

I’m going to drive this combo for a while, perhaps move up to 6.5 pv from 5.0 pv.

The throttle plates are still drilled, perhaps I’ll solder them up now idle vacuum is steadier after the last lashing and see if idle mixture can be better tuned.

Any ideas aside from a new carb?

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I am wondering what will happen after you solder up the holes. You might be able to tune it better and get a crisper off idle response.

Generally running leaner gives you a crisper response, but you need that power valve to kick in so it won't go lean and ping on the hills.

Do you have a super heavy long looped spring on the secondary side of the distributor to stop max mechanical advance? You mentioned you had the heavy black spring on the primary side and lengthened as much as you could by adjusting the spring post out.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Ted: Yes
Timing at idle and dropping high rpm back to idle is now under control.
I’m on that same page, inquiring minds need to know, I’ll fill’em in and retune mixture. She is a bit of a slug taking off, no empirical data to confirm this, only based on fabric located just forward of my back pocket.

Another thought that breezed through my scull in the last 24 hours concerns PCV valve currently installed, is it passing enough air to lean out small cruise throttle openings or should it? It came from Rock Auto listed as correct for slant six, I assume a stock build slant, but would a modified slant sporting a much larger carburetor have different requirements? This is the only other controlled vacuum leak aside from cooling air passing through Holley’s electric choke which exhausts to intake manifold via a small orifice dead center of four bores.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Bill,

If you do decide to buy one, replace it with a SMP V180. It has a metal barrel. They are much nicer than those cheap plastic ones that rattle (V165).

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Its metallic with: “MV 781 PCV made in USA, with two little up pointing arrows stamped on valve of unknown manufacture. Rock no longer has a listing. I did see the 180 valve listed.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Soldering up of throttle plates has been completed, resetting of secondary throttle plates to allow more air in to lean mixture done, a quickie idle mixture tune made, 6.5 PV replaces 5.0 PV, and a test drive completed. She still runs rich at small throttle opening during cruise, under light acceleration, and there is a slight flat spot caused by mal adjusted accelerator pump arm.

While carburetor was on bench I discovered the secondary throttle plates were jammed closed, no wonder the acceleration has been doggy… She pulls hard again now. Hopefully slight cracking open of plates will prevent future jamming.

Perhaps a bit more air past secondary throttle plates would lean out cruise. I did not take a pull on my red neck dyno tonight to test off idle torque… It was too dark to examine any pavement markings.

I was able to turn idle mixture screws in almost an additional half turn; they should be about 1.5 turns out now. Idle mixture keeps running rich to lean to rich back to lean rhythmically. Engine is barely loping with loosened lash, and easily settled down to 800 rpm in park, and once shifted into R or D would passively drop to 500 rpm and continue to tick over as nothing happened. This is something new wanting to idle down.

Tomorrow I need to fine tune idle mixture, and secondary throttle plate stop in a quest to lean out cruise, and try to stabilize idle mixture from running rich-lean-rich-lean...

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Bill,

Awesome!
The extra lash really lets you dial in the carb....
Nice work!
And thanks for sharing!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Mrs. Wjajr and me went for a little 70 mile spin down on the coast in our first 90+ degree day, and had lunch at a local brew pub where a pastrami sandwich was washed down with Irish Bastard ale and some fish & chips for the Mrs.

Most of the trip was at 2500 or less rpm. (50 mph), and at these low speeds there is a lean surge at times, too often for me, so the 50 jets are going in and back to 5.0Hg PV once engine has cooled. I think I want to run on main jets a little longer before dipping into PV. With the present 49jet/6.5PV combo power comes on like a switch was thrown once PV opens with very little throttle opening.

I did try the red neck dino, engine easily spins tires with part throttle while power breaking indicating torque curve has migrated down the rpm band. With a lower steady idle, and 2400 or so stall converter she is now wants to go, but also can easily be driven in a mild manner with no neck snapping P to R or P to D gear changes as previously experienced.

After tuning idle mixture with volt meter, and vacuum gage I discovered idle mixture screws were only 1.1 turns out, and once out on the road engine refused to stay running once car came to a stop. A half turn out fixed the in gear idling problem, but a rolling mixture, more on the rich side, is generating some stinky exhaust.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

After some trench and dirt work restoring front lawn, a relic of geo project, I moved on to less laborious stuff; changing jets from 49 to 50, and swapping 6.5 PV back to 5.0Hg PV. I did no idle mixture tuning, slapped in the new stuff, and went for a ride.

Lean surge seems to be gone, still rich at constant small throttle opening cruise, and a little bit if a flat spot on tip-in under light acceleration but non with a larger throttle movement. I’ll have to check accelerator pump lever’s adjustment, when R&R fuel bowl it never seems to go back in the same position.

Car drives well, idles in gear around 800 rpm without any left footing and feathering gas. Idling in park at 1000 rpm is a bit rich, but I think idle mixture adjustment will reign in that problem.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Bill,

Now that your back to normal settings I hate to mention this, but you may have to go to larger air bleeds to fine tune the idle/cruise mix to perfection. Or at least run some fishing line down the tubes to be sure they are not blocked.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

It's been a while, but I think on the 8007 the idle bleed is closed at the factory and would have to be drilled to open it, the high speed bleed has a hole but that's not the circuit he's tuning.

-D.Idiot

Last fall I purchased a [url=http://www.quickfueltechnology.com/metering-blocks-and-parts/primary-billet-metering-block-standard-calibration-w--spark-185033104776477747784779.html]Quick Fuel Technology 34-8 metering block[/url]. I did not install it because the brass tube connecting Holley’s metering block to accelerator pump has to be cut for the QF part to fit.

If I can get a replacement brass fuel tube (it’s about half inch long with an “Oâ€￾ ring at each end) to restore my 390 if the QF part doesn’t work out, then I’ll install the QF block.

Ted:
[quote]Or at least run some fishing line down the tubes to be sure they are not blocked.[/quote]

The last time I had carb open I flushed the air bleeds out.

DI:
[quote]but I think on the 8007 the idle bleed is closed at the factory[/quote]

Idle or high speed, one or the other bleed is plugged from factory I don’t recall which is which. However according to Holley Tech line dude there is a very fine hole in the “Pluggedâ€￾ set, but I’ll be damned I can see any fine hole.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC