Engine wants to die when put into gear

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jlwhitney35
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Engine wants to die when put into gear

Post by jlwhitney35 » Wed Jun 05, 2019 2:32 pm

My '75 is roadworthy, but the one issue dogging me is just what the title says.

1800 motor, stock carb and intake.

Timing (static and running) is set. When I engage the transmission with clutch pedal still depressed (either first gear or reverse, doesn't matter) the rpm drops to the point that the engine will die if I''m not quick enough to give it some gas.
I have the idle set a little high, the mixture is set (plugs burn clean) and the motor runs pretty smooth at idle.

Hopefully there is a simple fix or at least a bit of troubleshooting suggestions, I'm open.

Getting ready to sell her and would like it to be right.

Thanks Jeff
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miker
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Re: Engine wants to die when put into gear

Post by miker » Wed Jun 05, 2019 2:54 pm

Does the idle drop when the car is in neutral and you just press the brake?
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jlwhitney35
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Re: Engine wants to die when put into gear

Post by jlwhitney35 » Wed Jun 05, 2019 3:10 pm

I'll try that Mike, but as I remember that is not the case.

Just went out and tried it, but the brake has no effect. In other words, I have the car on level ground, motor running, put it into gear with clutch depressed and the rpm drops off to the point the engine will quit.
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bartigue
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Re: Engine wants to die when put into gear

Post by bartigue » Wed Jun 05, 2019 3:15 pm

Which gear?
Does this car still have the high idle device and if so, are the hoses intact?
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jlwhitney35
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Re: Engine wants to die when put into gear

Post by jlwhitney35 » Wed Jun 05, 2019 3:35 pm

First and reverse. That was from this morning when I was getting ready to test drive it in the neighborhood.
The last time I test drove was two weeks ago and as I remember, it didn't matter which gear. At the time, I thought that maybe I just didn't have the timing, etc. not set correctly.


Is the high idle device the relay with a button on top which is mounted on the fender? It has a wire attached, when the engine is idling and I depress the button, it has no effect (although I can hear what sounds like a relay closing when I depress it).
Not sure of the hoses you are talking about or the other item you mentioned.
If you can point me in the right direction, I'll check.

Thank You
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Re: Engine wants to die when put into gear

Post by davedecker4 » Thu Jun 06, 2019 1:26 am

Check for a vacuum leak. Or your choke stuck on?
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friedman
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Re: Engine wants to die when put into gear

Post by friedman » Thu Jun 06, 2019 8:10 am

Does the rpm drop by just stepping on the clutch pedal, even if you are in neutral?
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jlwhitney35
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Re: Engine wants to die when put into gear

Post by jlwhitney35 » Thu Jun 06, 2019 9:04 am

"Does the rpm drop by just stepping on the clutch pedal, even if you are in neutral?"

I'll try that later today. Would that imply that the relay that is located on the clutch pedal is the culprit? If so, a replacement would be in order, or is there an adjustment on it that can be made? Haven't looked that closely at it , but will this evening.

Do the vendors even carry that relay? Did a cursory search but not exactly sure I'm using the right terminology.

Thanks for the input.
Jeff
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bartigue
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Re: Engine wants to die when put into gear

Post by bartigue » Thu Jun 06, 2019 4:39 pm

A malfunctioning high idle system can cause what you describe. Easiest thing to do is eliminate it; remote the device and cap off the ports.

Curious to know if you’re pushing the brake. If you’re pushing the brake and the clutch then I’d be thinking brake booster diaphragm failure. Easy enough to cap that port too when diagnosing
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jlwhitney35
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Re: Engine wants to die when put into gear

Post by jlwhitney35 » Thu Jun 06, 2019 7:12 pm

bartigue wrote:
Thu Jun 06, 2019 4:39 pm
A malfunctioning high idle system can cause what you describe. Easiest thing to do is eliminate it; remote the device and cap off the ports.

Curious to know if you’re pushing the brake. If you’re pushing the brake and the clutch then I’d be thinking brake booster diaphragm failure. Easy enough to cap that port too when diagnosing
I started the motor, pushed the clutch in and tried each gear (5 forward and reverse) and each shift causes the engine to drop to the point that it will quit (brake pedal had no effect).

To clarify Brad,for this barely sufficient mechanic brain of mine, tell me in baby steps the high idle system, "remote the device" and what ports are we talking about?
On what may be a separate point, the relay button that the clutch pedal physically activates, seems to have no effect on anything. I unplugged both wires attached to it and nothing happened. As a matter-of-fact, the pedal retracts to point that it only barely contacts the button, so when the pedal is fully released, the button does not depress.

Thanks for your patience.
Jeff
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