What about your trans converter? Is it too tight, when you drop it in gear how many RPMs do you drop? It would be more noticeable when warm because your high idle would be off.???
Of course if we are talking something aftermarket. I was referring to the stock one that mounts to the intake.
With the motor up to operating temp, RPM drops about 200 going from neutral to drive. That's with TSPs 9 1/2 inch 2800-3000 converter. So, to keep the motor from stalling out in drive I have to set idle RPM in neutral to about 1100 so it will not drop below 900 in drive. This makes going from neutral to reverse or drive a very violent shift. Vacuum is solid at 15 hg at 900 RPM. Total advance is 36 degrees all in at about 3000 RPM. Initial advance is at 24 deg. and centrifugal is 12 deg. I've also tried using about 8 degrees of manifold vacuum advance (rather than ported) which brings the idle advance to about 32. After adjusting the idle back down to 1000 the engine will still stall in drive when dropping to 800. When on his test stamd Jim said it would idle at 800 with no problem. I wonder if adding the torque converter and fluid would add enough load to cause a problem like I'm having? Would a cam designed for a 4-speed also cause a need for a higher idle? I'm grabbing at straws but will know more when I either install points in place of the LL conversion, as has been suggested, or install the MSD Pro Billet?
I would have a very close look at where your advance curve STARTS. If there is enough mechanical advance in at your in Park idle speed, the added load of the converter can slow the engine and the mechanical timing drops out. The same thing with manifold vacuum advance, you lose some of it. I have locked out timing, so it is always at 35*. My out of gear idle speed is 900 RPM, and it drops to 750 in gear. It never stalls even in 90* temps using E10 gasoline.
I’ve looked at that several times my centrifugal comes in at about 1100 and when I drop into drive I lose about 1 degree of idle timing. I’ll have another look when the motor is hot.
1100 rpm is nuts. I'd lean towards an idle circuit issue. Did you set the idle mixture with a vacuum gauge? How does it stall? Does it shut right off or peter out?
The two carbs I’ve tried were both performance tuned. One by Robb Ross and the other by Evertday Performance: Idle mixture was set with a vacuum gauge. Tachometer, and dial back timing light. When stopping at a traffic light engine rpm fluctuates once or twice between 900 and 1000 and then just cuts off. But it’ll start right back up.
Maybe the modifications to make the QJ perform on the Dyno without going lean, make it too rich for the heat? Ever put an AFR gauge on it?
If it just dies and doesn't sputter I'd go for an ignition issue. I'd measure idle voltage at the coil and make sure its within spec for your elimination kit. I've never had luck with those kits, I'd also swap a normal point in, set the dwell and reset the timing and see what happens.
Vacuum leak ...I just went through the same crap swapping carbs twistin distributors and at the end of the day it was a leaking brake booster.
I had a booster on my 66 that only leaked when the pedal was pressed. It was obvious as it was leaking inside the car. It would be easy enough to pinch off the booster line and see if it changes.
I agree and sorry to add to the confusion. If it's possible to have my issue transferred to a new thread, I'd be happy with that.
Something here never mentioned. Try closing the choke halfway and see if the idle smooths out. This means that the car is running lean and it will have a big rpm difference between in park and in drive and will cause a stall in drive. There is a QJet modification to fix this in the idle circuit. It entails removing the idle circuit tubes from the carb body and cleaning the idle passages. I also drill the tubes out slightly larger and blow them out with carb cleaner. Makes a huge difference if that is the culprit, like many are. You won't believe the difference. This is also an important mod if you are running more than a stock cam.
OK everyone is going to dismiss my response but I chased this issue for most of a summer. Identical stalling issues. It was tied to the Lectricc points replacement.if you notice, both posters have one. I even got conformation from their tech support line that this is a known issue. In fact they were the ones that encouraged me to swap in my old coil. Sounds nuts but they strongly suggest you run their points replacement with an older delco remy coil. I can’t explain why but newer coils can cause stalling. (So can a bad ground if the disti is not well grounded to the block) I have tried 3 brands of newer oil filled coils (standard specs for a 430 not high performance) they all cause stalling. If I swap in an older delco remy coil, no issues. This spring I finally found a NOS Coil from the 80s and that also works fine. I called them multiple times trying to get a new coil that they recommended….they don’t have one. They tell you to use something made in USA but their are zero new options. I chased my tail for months thinking it was fuel or carb, etc. The car would stall at lights and then restart instantly. It drove me nuts. I suspect if you put the points back in it, it will not stall. Or, find an old coil and try that. I know this posts sounds foolish but look at the common denominator in the two folks having issues…both have these points replacements. Both describe the same bizarre symptoms.
Thank you for posting this info. Turns out I did call LL and they described the same problem and their recommended fix. They say it has to do with the resistance of the coil getting too high when the coil gets hot. I did check the coil resistance of both the NAPA coils I've tried and they are 1.4 and 1.6 ohms respectively when cold. When the motor is fully wormed up, they both go up to 1.9 to 2.0 ohms. LL says their spec is a max of 1.8 ohms. So, I did some voltage measurements at the coil with cold, warmer, and hot engine temps and with no accessories on and max accessories on. (A/C, High Beam lights interior lights and radio all on). Voltage at the coil using the factory resistive wire ranged from 10.5 to a low of 8.95. Based on this data I dismissed the NAPA coils as the problem because the car runs so great at all speeds except hot idle in drive. But, based on your experience I'm now gonna try to find an original Delco coil to see if I can duplicate your fix. Such a strange problem and I'm not sure I want to keep that LL conversion if the motor is on the hairy edge of the stalling problem all the time. Anyone got an original Delco coil they can loan me, which I'd return after testing it out?
