Re: {Chrysler 300} Ram tuning

The only 'issues' I've had with my G's (one coupe, one convertible) had to do with the little piston inside the round choke chamber that is responsible for 'choke pull off' after cold start.

Seems like either not enough vacuum to pull choke back off of initial start position to keep the car from running too rich after it starts, or the piston is not tight enough in the bore any longer and vacuum slips by without pulling the piston back against the spring tension of the choke? I've done the naughty thing of messing with the adjustment of the bi-metallic spring to try and have the cold tension just enough to close the choke without it 'snapping' shut, hoping to reduce the force the little piston has to pull against, but that really hasn't helped much.

That being said, car starts on fast idle (but doesn't drop down fast/soon enough for my liking), and after about a 30 second wait I can drive off without worrying about hesitation or stalling. Once warmed up and back down to curb idle, no hesitation at all in normal driving. If I adjust things to make it come off of fast idle sooner, I do get the hesitation/feathering issue until the car has been running a few minutes, so I leave it the other way and just compensate by having my initial 'fast idle' set a few rpm lower than it probably should be by the book to minimize the initial shock into reverse when backing out of the garage.

Someone told me decades ago (I think a local transmission guy in MA) that Chrysler transmissions got a bad reputation for the reverse band breaking, when it was really caused by owners failing to 'blip' the carb down off of fast idle cam before engaging reverse to back out of the garage or driveway when cold, thus putting more stress on the band as well as the u-joints.

The 61 NYer limo I bought from Neil Freeman in Whitehall, MT had a broken reverse band, which made for an interesting ride back to MA with no reverse. Being an 8 door limo of around 24+ feet in length, I wasn't doing much backing up anyway, and had 2 friends with me so we could push backwards if/when necessary. Ah, youthful exuberance!

I had one other issue with my G coupe that I could never understand and would love to have someone explain. Never had any starting/stalling issue with my G coupe, but it did have a slight leak at the rear main seal. Drove the car up to Rinaldi's in Maine to have it fixed. Being high performance engine builders, Dominic was dead set against heavy oils like 20W50 (maybe even 10W40) as it 'robbed horsepower'. After replacement of the rear main seal, he installed some kind of very low viscosity/low friction oil in the engine. Once I got home, every time I would cold start the car it would start right up, but stall as soon as I put it in gear until/unless I let it warm up first. Almost like a vacuum leak or 'no torque' situation like John described. After a few days of this, I got mad at the car and changed the oil back to 20W50 and the problem went away and the car went back to normal. I found it impossible to figure out why the viscosity of oil would cause the cold stalling issue, even to this day.

Any ideas?

On Thu, Sep 17, 2026 at 7:37 AM John Grady <jkg@xxxxxxxxxxxxxxxxx> wrote:

This is an old subject but years have gone by and those interested in this , some pretty smart guys have gotten in pretty deep ..... I have " tuned " a lot of rams over the years and surprised by variability in final outcome . Despite a lot of effort, some cars kind of fight, you a few settle in.
This is not about obvious stuff we all know , it is about things rams do at times. Maybe all times , more or less . And some on site have really gained significant knowledge over past 20-30 years
I have one fighting me now , the constant fight between stable rpm at idle and slamming into gear and then stalling. As if idle has no torque if " loaded up" They even mention this " rough engaging" in user guide on F .
Part of it is due to unported vacuum to ignition , always full advance at idle . If vacuum drops ,at trans engage, ( it does) ignition retards = stall . I mean this is real and anti stall thing grew out of it, but opening throttle more just off idle drops vacuum more . Thin line there . And I think design is flat out wrong we have to tune around it .. I was thinking ??? add a small vacuum can and orifice to slow down advance action , or buy carbs with ported vacuum like every single other car the world has . Carl did that his car runs great . AVS calls to me ..
The second thing is the tendency to stall off a stop sign depending how much you feather pedal .
It feels like it goes lean momentarily ( remember this is some cars not all)
So seems like carb squirt is either late to the party with small thrittle motion startup off idle , not enough gas , or idle mixture wants to be richer than optimal ( as set by vacuum gauge) to cover this transition It us really bad puling into traffic and car suddenly stalls, adds stress to driving . This is tangled around issue 1
I am ignoring warm up issues , another whole thing , but gets into this in first 15 minutes

Lets call it ole ram guys , philosophy etc .

Can be made to be acceptable , yes, but really optimal -- no, not easy to get to . And how about ignition timing ? they say "no spec for that idle timing with vacuum on , just set with off" .but it IS on st idle . And high , ? leading to above sensitivity to stalling slamming all that
Deep thinkers on this , insights gained welcome ..
J

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