Stalling at idle in gear

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73duster47

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I've been chasing a problem with my engine stalling in gear once it gets hot ever since I got it running, and I'm hoping someone here can point me in the right direction to possibly fix this thing.
Engine is a 408 small block, 670cfm holley carb with a 1/2" phenolic spacer. Trans is a 727 that was converted to run with a lock-up converter at the advice/decision of the guy that built my trans. 3.23 rear gear. Fuel pump is a Carter electric and I'm running it through a regulator and getting 5.5psi consistantly at the carb. Engine RPM in neutral is about 1100-1200, in gear is 800-900.
When it stalled today it was at the end of a 12ish mile drive to the parts store, right when I was about to turn onto my street, and it stalled again when I got in my driveway. Once in the driveway I started it in neutral and as soon as I put it in drive it died. Let it sit off for about a minute, fired it up, put it in gear and it idled in gear for about 30 seconds before it died. Water temp got up to 220 since I had to wait for a train and didn't drop much once I got rolling again (no shroud at this time, waiting on some welding resources and will have a custom one on next weekend).
I thought I had fixed this problem with the fuel pressure regulator since before I put it on I was getting 8-9psi at the carb and flooding the carb. Apparently that wasn't the only issue. I'm thinking it's the lockup converter not disengaging and really hoping that that's not the problem. Is there any way I can test that without having to drop the trans and pull it out? Anyone else experience this issue and have any advice at all that they can share?
I'd really like to be able to drive more than 12 miles without this thing stalling.
Thanks.
 
What stall speed are you running on your converter? If you have a lopy idle from the camshaft, I'd up the stall to 2500-3000. I had experienced a similar problem that was resolved with a higher stall.
Andy
 
I have no clue what my stall speed is. It's supposedly a stock 360 lock-up converter that the guy who built my trans picked up and put in. I'm thinking that was a big mistake on my end, letting him do that and just plain going to lockup to begin with.
And of course he's not answering his phone at all today.
 
Just looked it up. Stall speed should be 2100 on it.
Here are the specs on my cam: 474 Intake / .474 Exhaust & 238 Intake / 238 Exhaust duration @ .050 - 110 degree lobe separation

Would the lockup input shaft work with a non-lockup converter? I do have a non-lockup input shaft I could use if I decide to ditch the lockup.
 
Idle sounds a bit high , what's timing set at ? I had a problem like that , timing , fuel mix were off , I was up around 1100 as well , thinking that would cure the stall problem it didn't . Had to play with timing , mixture and idle speed , now at 900 neutral 800-850 in gear .
 
I had a similar problem early last month on my Cuda. Thought was vapor lock, fuel pressure too high,etc.... It was the MP Orange ECU box that went out. If you do have electronic ignition, check your orange or chrome ECU box. Hope this helps!!
 
Jerry6, Timing is at 14 initial and 32 total advance. Vacum advance is not hooked up. All as per the booklet that came with the crate engine says.
Hawaii, I never thought the ecu would do it, but I am running the Orange box. Will check that out.

Thanks guys.
 
Sounds kinda like a converter problem to me. Actually had what sounds like the same problem with my car. Changing to a higher stall converter fixed my problem. My car would not idle at all in gear.
 
70408, when you say that it would not idle in gear at all, is that when you first put in in gear or after driving around for a bit?

I'm thinking it's the lockup that's my problem and not the stall speed because I can tell when the lockup happens, it's like an extra little shift, and the stalling only happens after I've been cruising for a bit at constant speed after lockup occurs. then once I get it restarted (no hot start issues at all, cranks easy and fires quick btw) it stalls as soon as I drop it in gear unless I put my foot in it from the get go.

Thanks!
 
I'm dealing with a similar problem. Does your car try to push you forward at idle when it doesn't quite stall or as it is stalling? Does it NOT do this in reverse? Just curious. We may have the same problem. I believe mine is due to my idle being too high as crazy as that sounds. But, I have some other problems forcing me to keep the Idle higher than it really should be. I will closely watch this thread as I try to fix mine. BTW, Most if not all late 70's & up converters used lock-up for fuel economy.
 
Most the time it stalls as I am coming to a stop. Doesn't feel like it's pushing me forward at all. I had the revs up thinking that it was too low, but left it alone after fixing some fueling issues. It stumbles a little in reverse, which is also why I think the converter may be an issue. It stays running if I shove it into neutral once it starts sputtering.
I let the guy who built the trans put the lockup in thinking it'd help with fuel economy, but that doesn't mean crap to me if I can barely drive the thing. If the lockup isn't releasing then it's putting too much of a load on the engine at idle and making it stall. I don't want that part of it haha.
 
If the lock-up is staying engaged, then it would seemingly "Push" you forward until it stalls due to the brakes locking up the engine. When it unlocks you go back to fluid only which(at lower Rpm's) shouldn't push you very hard and shouldn't stall the engine. I can't see how Stall speed could affect anything at idle. If your "stuck" in lock-up then it's kind of like trying to stop a 4-speed without pushing the clutch in. I guess what I'm getting at is that if it doesn't feel like you're stalling out a 4-speed then I don't think the lock-up is failing.
 
Most of my experience with 4 speeds is stalling them haha, and it feels similar, but not quite the same.
I wish I had video of this happening from the driver's seat. I think that'd help a bit.
 
try adjusting the idle mixture screws on the holley carb...screw them all the way in...then turn them out 1 turn each...slowing move each one 1/4 turn...get a vacuum gauge and adjust for the highest vacuum....

also you might try flipping the carb over and making a small adjustment to the rear throttle blade...open them up just a hair to allow more air to get in
 
Well, I tried a few things and here are the results:
Vacuum at idle = 15 inHg
Vacuum in gear = 10 inHg
Timing = 14 Degrees advance initial, 34 degrees advance total (@ 3000 rpm) - Dead nuts on what the booklet that came with the crate engine says it should be.
Fuel pressure was steady at 5psi.
Fuel levels in the float bowls was right at the bottom of the sight holes the entire time.
I let the engine temp get up to 220 then drove it around the neighborhood a few times, totalling 8 miles. Engine temp never got below 210, and I made some hard stops trying to flood the carb, but no dice.
The thing never stalled, never even hiccuped. I got on it hard and then slammed on the brakes but nothing.
I never cruised long enough to feel the converter lockup, and with all this today I'm really thinking the fuel system is ok, and the converter is still the issue.
Current converter stall is I think 1800.
 
73duster47 said:
Would the lockup input shaft work with a non-lockup converter? I do have a non-lockup input shaft I could use if I decide to ditch the lockup.
Click to expand...

No it will not, trans needs to come out and input shaft changed.

You should be able to find a 10 inch lock up with a 3,000 stall. Plan on around $750 for it but that is only $200 more than what a good 10 inch should cost and you get better mpg, go for it
 
Before I change my converter the would idle just fine in park and neutral but the minute you put in gear it would just die. Didn't matter if it was forward or reverse it would just die. I have what I think is a stout 360 in my Dart. 73 360 bored 30 over, stock stroke, stock rods, Keith black hypertectic kb107 pistons, out of the box edlebrock heads, Huges Engines cam 540 lift exhaust side and 524 lift intake side (if I remember right), eddy air gap intake, hollley street avenger 77cfm carb, 727 trans, 3:55 geared 8.75 rear.
 
Dodge Freak, you think that my problem is a result of the stall speed being too low?
3000 seems kind of high, I was thinking I needed closer to 2500.
The car is a street car, going to be a daily driver eventually.
Is there a chart or something I can look at to determine the stall speed I need? I know TCI had one on their website at one point but I can't find it anymore.
I think I'm going to give A&A Trans a call tomorrow morning and see what they have to say.
Thanks
 
Is it dropping timing when put in gear? It's at 14* when in park, then drops to something lower in gear? Check timing in gear and make sure it's constant at 14*.

It may want more initial.

IMO, that cam in a 408 should idle around 900-950 rpm in park, no problem, maybe even lower. The current RPM drop from park to in gear is WAY too big.
 
Timing does not drop when it goes in gear. That stays the same.

I'd like to get it to idle at 850-900 in neutral and 750-800 in gear. One reason I have it up as high as I do is that if I hold the throttle to 1300ish RPM in gear when it starts to stall it won't stall.
Would the stall speed of the converter have anything to do with the drop in rpm from neutral/park to being in gear? If it's miss-matched that could cause the large drop correct?
Thanks!
 
Vacuum leak will cause a big drop.

Tight converters as well, BUT, that isn't a big cam for a 408. No reason for ti to not idle down and have an acceptable RPM drop in gear.
 
There's no vacum leak. Only thing I have hook up for vacum is the brake booster and spraying starting fluid around the carb base flange, spacer, and intake/head flanges yielded no change in the engine. It just kept humming along at idle.

What would be an "acceptable" drop in RPM in your opinion?
And what do you mean by a "Tight" converter? Too low of a stall speed or locked up?

Thanks!
 
as simple as a float needle not seating causing the engine to go rich when it idles down.
You did say if you hold the idle up it won't die.
 
With a (big) cam you won't get it to idle like a stock motor. 800rpm.
I have a mp 484/282 purple shaft in the duster. It dosn't like to idle
any lower than 900-950 in gear.
 
Get the hot idle in park set correctly first, then see what the idle drop is when you stick it in gear. With that high an idle, you may be getting a false reading on your initial timing.
 
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