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RPMs slow to raise, lights dimming badly...connection??
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Author:  scottdart [ Mon Jan 30, 2012 9:56 am ]
Post subject:  RPMs slow to raise, lights dimming badly...connection??

I have a 68' Dart 270 ( 225 6cyl ) and it's been running like a champ for most of the near 3 yrs I had it ( thanks to many folks here for help along the way).

Since the weather has turned colder it's been doing something odd. Usually it behaves pretty much the same from season to season, but not so far this winter. One thing that's happening is when I go to start it up in the morn. I'll tap on the gas ( to close the choke ) then I'll crank it, and it turns over very well ..almost instantly. At this point it usually is running at the highest idle ( about 2500) up on the first step. Of course, I'll tap the gas a couple more times to kick down to lower idles ..then drive away. Recently however, when I start it up it's taking about 2min for it to get up to the high idle of 2500rpm. It has always immediately gone to the 2500rpm status on start up, but now it's taking it's time. Ever once in awhile it will go to the high RPM like normal but that's rare right now.

Any thoughts about this, what I might check or do?

The other thing that has caught my attention is what seems like a power/electrical problem. My headlights use to just barely dim a tad when I'd let off the throttle and brighten just a hair when I'd accelerate. It was all really unnoticeable. But now I notice not only that the headlights are dimming much more considerably, but when I have the heat blowing, it too will blow either normally or get weaker, depending on if I'm pressing the gas or not. This effecting the blower too, is a new occurrence.
This seemingly electrical issue began about the same time as the slowly raising RPM issue.

Could there be a connection? Any tips on what I can do? Remember I'm still learning about these engines so answer me like you would a rookie.

Thanks

Author:  SDale [ Mon Jan 30, 2012 11:01 am ]
Post subject: 

For the electrical side, check the basics. Battery in good order, cables and lugs in good shape etc. Check to make sure none of the field wires popped off of the alternator. Also check the bulkhead connectors and check the voltage regulator ground to make sure there's no corrosion built up behind it.

You can also check voltages upstream of the ballast resistor and the hot side if the coil to make sure you're getting good power.

Author:  wjajr [ Tue Jan 31, 2012 5:19 am ]
Post subject: 

Give the choke linkage a good cleaning, check for binding after it’s dried, and freedom of movement.

Author:  SlantSixDan [ Tue Jan 31, 2012 9:28 am ]
Post subject: 

Time for some maintenance. Tune-up parts and technique suggestions in this thread. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. And how long since the last valve adjustment?

Author:  75duster [ Tue Jan 31, 2012 8:14 pm ]
Post subject: 

when its taking awhile to get up to 2500 does it seem to load up or feel like its flooding out on everyother cylinder? my 75 with a bbd does that for a few minutes till it gets some heat to the cylinders. gotta get the choke set right, otherwise it will pull too much fuel and have problems lighting off cold. i wind up chasing the rpm with my foot for a little bit till it clears up. also had similar problems with lights and heater, found the charge back wire from the alt was loose on the starter relay on the firewall. it feeds from alt toe post on relay and back to batt.

Author:  stop the beast [ Tue Jan 31, 2012 8:34 pm ]
Post subject: 

For the electrical issues, it sound like a bad alternator or bad connections to me. I've had the same exact issues and it was loose connections at first and then a bad alternator down the road.

Author:  scottdart [ Wed Feb 01, 2012 9:39 am ]
Post subject: 

Thanks for the insight into what I can check. I will say that I had a tune-up, including a valve adjustment, in late Nov. last year. It was starting to exhibiting some of the same issues prior to that tune-up.

I'll check out some of the things that have been mentioned and see if hopefully, I can find a definitive cause for the problem.

Author:  Josh P [ Wed Feb 01, 2012 5:56 pm ]
Post subject: 

Out of curiosity... has the head been fitted with hard exhaust seats or do you use a lead additive/substitue? You may want to check the valve adjustment again and see if they are tight again.

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