Brought home a '70 Challenger SE, 383 auto. Car runs and idles great but dies when putting in gear. I have the idle set at 1200rpm and it still dies. Not sure which trans I have yet since I just got the car. I know the trans has some type shift kit but unknown. When putting it in gear and the engine wants to die then putting it back in park it continues to run bad for 10-15 seconds before returning to good idle. Any thoughts? And thanks for the help.
Engine dies when putting in gear
- Thread starter Lanman70
- Start date
shovelhead
Member
Yes put vacuum gauge on and check for steady gauge reading unless camshaft is too extreme.I think it may be electrical as in battery not supplying enough volts to coil.Under load when gear selected revs drop and so does volts to coil.Is it standard mopar ignition system or updated electronic ignition?Voltage regulator may be faulty or need updating to electronic type if you are now using electronic ignition.So check battery,all electrical connections,terminals,get multi meter checks done,test battery,voltage reg and alternator first.My duster had same issue and it was voltage drop causing weak poor spark ,new electrical volt reg fixed issue.
pschlosser
Well-Known Member
The only vacuum or electrically-related issue a 727 transmission may have (I can think of) would be the reverse/neutral safety switch.
I'm thinking when you leave park, and cross reverse and neutral, there MAY be some electrical interaction, there.
The neutral safety switch is unused (more or less) once the car is running. Both of these lines could be disconnected and the tranny shifted around to see if the engine behaves any differently.
What's your charge-discharge gauge showing when shifting in and out of gear?
I'm thinking when you leave park, and cross reverse and neutral, there MAY be some electrical interaction, there.
The neutral safety switch is unused (more or less) once the car is running. Both of these lines could be disconnected and the tranny shifted around to see if the engine behaves any differently.
What's your charge-discharge gauge showing when shifting in and out of gear?
Chryco Psycho
Well-Known Member
All to do with tuning , the vacuum hose to the dist should have no vacuum at idle & increasing with RPM . sounds like the timng & carb adjustments are way off . If you PM me I can call & work through this with you .
Appears to be standard Mopar ignition with exception of plug wires. Stock intake manifold and carb. Engine internals are unknown and has headers. The car idles very smooth before putting in gear. Thanks for the reply. I will continue to test and look for the answer.
I will watch the gauge next time I try to solve the problem, thanks
Challenger RTA
Well-Known Member
As Chryco Psyco implied. I would go back to basics. tune up even when you think things are good. Check cap,rotor,plugs,plug wires,coil power to coil,choke and vacuum. distributor advance moving? Then maybe check choke, carb adj and jetting. Just my thoughts.
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Thanks for the reply, will do. It runs so good it's hard to believe it is so far out of tune but I will check it all out.
pschlosser
Well-Known Member
We motor heads are not there. We can only go on what we read.
I'm dubious the tranny is causing the issue described, but maybe it's possible.
As others intuitively suggest, maybe it's only after the tranny engages, and the engine RPMs drop, do you see an issue. I may have thought you would have seen those issues in neutral, but again, we are not there. Our ability to discern and analyze is limited to the data you give us.
That said, a running video of it being started, warming up, and being placed into gear may give us new leads. (hint, hint, nudge, nudge)
I'm dubious the tranny is causing the issue described, but maybe it's possible.
As others intuitively suggest, maybe it's only after the tranny engages, and the engine RPMs drop, do you see an issue. I may have thought you would have seen those issues in neutral, but again, we are not there. Our ability to discern and analyze is limited to the data you give us.
That said, a running video of it being started, warming up, and being placed into gear may give us new leads. (hint, hint, nudge, nudge)
As I'm sitting here at work and thinking about the car, I know the idle adjusting screw is turned in a lot which would open the butterflies and create vacuum to the advance. Hose is currently connected passenger side small port.
Challenger RTA
Well-Known Member
Turn all the way in.turn out counter clockwise 1 1/4 turns. Good starting point.
Xcudame
Well-Known Member
1200rpm idle will definitely allow the vacuum advance to engage. As Chryco Physco mentioned, it sounds like the tune is out of whack. The fast idle is masking something. Probably a vacuum leak. I doubt it's the transmission unless something inside the transmission is causing a huge parasitic draw in power. Hooking up a vacuum gauge should tell you a lot.
pschlosser
Well-Known Member
Consider plugging the vacuum advance to the distributor until you resolve these issue(s). I'm not sure you need it for this test, and you may benefit from a simpler setup while troubleshooting.
Quick update! I looked inside the carb and could see the butterflies were open at idle which was causing the high vacuum at the distributor advance. After backing the idle speed screw completely off the throttle arm, the vacuum at the distributor advance is minimal. Also played with advance and retarding the distributor. I haven't put the timing light on yet but at least it will stay running when in gear. I will work on get the tune corrected and that should solve my problem. Thanks everyone for the input.
Xcudame
Well-Known Member
Yay! Good news! Hopefully you can enjoy driving it soon!
So obviously not a tranny issue but lesson learned, original thought was some type of vacuum modulator on the trans. Now I know to get the car tuned upfront and then deal with the demons. Thanks again. It runs great, took it for a spin to get gas! Oh yeah, Chryco Psycho dead on! thank you
pschlosser
Well-Known Member
Well done, @Lanman70 keep us updated on your adventure 
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