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Dying in gear after getting to operating temperature
https://www.slantsix.org/forum/viewtopic.php?t=39550
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Author:  KingofSwing [ Wed Mar 24, 2010 6:00 pm ]
Post subject:  Dying in gear after getting to operating temperature

Hello all,

I am new to posting on this board, but have visited it a couple of times. I have been fighting my slant six for the past couple of months. I have only recently been able to work on it and want to make it my daily driver.

Anyways, the problem I am having is that the car will run fine in gear, although it idles pretty high (i need to get a tach on it to be exact). When it has been started cold I can drive it around like normal, but it is definitely running at a higher rpm than it should. Once it gets to operating temperature the idles slows a bit which is usually the case, but when i go to put it in drive or reverse it wants stumble a bit then shut off. If i keep my foot in the gas a little it will usually get past the stumble and keep running, but if i slow to a stop it tries to shut off again. Also when i try adjusting the idle screw, it seems to have little to no effect. I have changed settings on the carb, timing, etc. nothing really seems to change it. I am not familiar with slant sixes or mopars for that matter even though i love the cars, i have been racing pontiacs for the past couple of years (sorry). I am hoping someone has had a very similar problem that can make for a quick fix.

Side note - I recently rebuilt the carb myself and it appeared to not really have anything wrong with it, although i am not ruling that out.

Car is a 1973 Dart Swinger, all original, 225/904
Electronic Ignition
Holley 1920
(just some specs to possibly help)

Author:  SlantSixDan [ Wed Mar 24, 2010 6:17 pm ]
Post subject: 

Welcome on the board. You'll want to get the three books described in this thread as quickly as you can.

Your issue is likely related to the engine's state of tune (ignition + carburetion + other adjustable factors). Tune-up parts and technique suggestions in this thread. The engine will need periodic valve adjustment. Extensive material on repairing, adjusting, and upgrading the Holley 1920 carburetor can be had in this thread.

Author:  Dart270 [ Fri Mar 26, 2010 6:29 am ]
Post subject: 

First thing to do is adjust the valve lash.

Welcome!

Lou

Author:  theslantingsix [ Tue Mar 30, 2010 5:56 pm ]
Post subject: 

man i had that problem on my duster back when it was a one barrol i wired the choke shut for a quick fix but ya might need a choke pull off i think its called, or convert it to a manual choke would work to

Author:  bootsnbolts [ Thu Apr 08, 2010 1:40 pm ]
Post subject: 

whoops, i've been having the same problem in the 67 plymouth valiant i bought last week. had a wee (free) diagnostic run at a garage i trust (yes, i trust...they've talked me out of spending my money with them twice now, and asked me to only bring it in for the sensitive stuff), and they told me, intake manifold gasket. yesterday i had that replaced along with the valve gauge gasket. zippity zoom, not so much. still stalling out.

head is ok, no knocking or other alarming sounds from engine (GO SLANT SIX!!!), so whether the gaskets helped or not, at least i am not stressing out big time over blowing a valve. i will PARK IT and leave it parked if there is ANY chance driving it, before repairs, would do serious damage.

my honey has a 1920 model holley carb, the air intake ain't what it used to be & the spring in the THINGY barely works at all. i was really interested in the above comment about...wiring it shut? i'd love to be able to go get my kid from school in something that doesn't smell like pee (public bus) whilst i await a rebuild kit or buy the one listed for $110.

i don't know if this will help the fella who posted this thread originally, or if he has resolved his issue, but in my quest for steady idle at stops, these are the things i have been looking into:

accelerator pump
intake manifold gasket
carburettor & it's myriad joys
vacuum leak
plugs & wires
timing chain stretch - mopar site says this is COMMON

the guy who sold it to me said to throw some crab cleaner in the carb...had him do that, also adjusted idle at that time. ran smooth for that day, stalled out again next day.

if anyone can add to this list, please do!

Author:  radarsonwheels [ Thu Apr 08, 2010 3:25 pm ]
Post subject:  stalling in D

I had some trouble with this too. For almost a year I had my curb idle (idle speed screw) set to around 1200 just so it would run at 800 or so in Drive with the brake on. It really banged into gear when you shifted to drive, but the trans didn't run hot so I let it slide for a while...

I ended up having to set the idle mixture screws for a slightly rich idle- more like 12:1 AFR than 14:1 AFR. Another strategy is adding a little initial timing. This can help to pep up the idle and make for crisp low rpm driving, but watch out- you don't want too much total timing, or pinging under low rpm high load.

Check to see that you aren't seeing a nice idle in neutral because the vacuum advance is helping, then when the vac. goes away in gear you have less initial timing and a sluggo motor that wants to stall. Know what I mean?

If you just want to drive for now you can always just run a high idle. It's probably a little rough on parts, but I'm a lot rough on parts so it didn't bother me.

Good luck man

Author:  bootsnbolts [ Thu Apr 08, 2010 4:59 pm ]
Post subject: 

mmmm...i don't think i can idle faster with my motor mounts the way they are. i've already got a shake going on to curl your hair. going to try new plugs and hope that settles the old girl down a bit, but motor mounts are vying for top place in priorities. just trying to keep the engine from getting damaged at this point, thank goodness it's a good engine!

i also have an auto tranny, tried to put it in neutral before i hit the slow speed that it dies at and i got grind. i'm a stick girl, so the whole auto trans thing has me a bit skeert, especially considering the battery seems to want to die overnight as of last night. i do like to be able to pop start, but oh well, time to get those cables.

Author:  Joshie225 [ Thu Apr 08, 2010 6:28 pm ]
Post subject: 

Sounds like you could use a hand. If the weather is decent at some point over the weekend and I stay away from the swap meet as I should I could drop by. We can try the unmolested Holley 1920 from my '67 Valiant on your car. It's just taking up space on the shelf after all. Could probably also do a valve adjustment. If I get the K-member in my Valiant swapped out later this year you can have my nice original motor mounts.

You must have hit park for the transmission to grind. It's pretty easy to go from drive just into neutral if the shifter is adjusted properly. Without pulling back on the lever when you move it the shifter should go from D to N and stop.

Author:  bootsnbolts [ Fri Apr 09, 2010 2:35 am ]
Post subject: 

ah, you must be around vancouver...? if that's an offer to come over, i'll be here aaaallll weekend. i'm NE portland.

i am doing the tune up research, making sure i can get the right bits for all of that, and was planning to start doing that as soon as possible, as it may help the motor rocking.

a lil ol holley 1920 would do us a world of good, and thank you for the advice with the neutral, i'll give it a try. providing she starts in the AM, battery was dead thurs. AM...different tale of woe.

unfortunately, i have to stay away from the swap meet for the same reason, i'm consoling myself that as soon as she's stable i can take her out to wildcat wrecking for our first out of town trip.talked to them on the phone yesterday, super helpful & nice, and i want to see the northwests' biggest mopar wrecking yard!

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