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Bogs down in gear
https://www.slantsix.org/forum/viewtopic.php?t=23193		 Page 1 of 1
Author:  mszauner [ Tue May 15, 2007 1:26 pm ]
Post subject:  Bogs down in gear
I was a somewhat regular poster here until I moved on to other projects. I know this is the best place to come for the slant 6 and I appreciate all the great help here.

My 1973 Duster has a 225 with 1920 Holley carb and automatic tranny. Lately, it has been having severe problems at idle. If I make adjustments, it may run better a few days then get bad again. Specifically, when in gear the engine bogs down so severely that it will quit or at least the oil pressure drops to nearly zero. If I take it out of gear, the engine speeds back up. I have rebuilt the carb, checked entire electrical system, checked for vacuum leaks and so on. It does fine in nuetral or park, but when placed in gear the rpms drop in a big way and it runs rough. Compression is fine too. This happens when the engine is warm only. I bought a dashpot and need to fabricate a mount for it but I am not sure this is the issue.

Thank you everyone and sorry I have not been able to visit in a while.
Author:  SlantSixDan [ Tue May 15, 2007 1:39 pm ]
Post subject: 
Dashpot won't help out -- that only helps with stalling upon releasing the gas. If it bogs down and dies when you put it in gear, there's still something the matter with the carburetor and/or distributor vacuum advance. Where's your initial timing set at? Do you have a timing light? If so, take a look at where the timing mark is with the engine idling in Park, then have a helper put the trans in gear while standing on the brakes (for safety) and see what happens to the timing mark.

I suspect your carburetor might be worn out beyond rebuilding. They get that way after a couple-few decades.
Author:  mszauner [ Tue May 15, 2007 2:31 pm ]
Post subject:  Thanks
I do have a timing light and I will try that. My older carb was worn out beyond rebuild so I bought a reman one and it was lousy. I rebuilt that one and it ran much better. I will let you know how the timing is.
Author:  sethmcneil [ Tue May 15, 2007 3:07 pm ]
Post subject: 
Dashpot? :?
Author:  SlantSixDan [ Tue May 15, 2007 3:29 pm ]
Post subject:  Re: Thanks
Quote:
I do have a timing light and I will try that. My older carb was worn out beyond rebuild so I bought a reman one and it was lousy. I rebuilt that one and it ran much better. I will let you know how the timing is.
Sometimes those reman units have worse internal problems than worn-out originals!

Lemme know if you're after a new-new one; I have a couple left.
Author:  mszauner [ Tue May 15, 2007 4:31 pm ]
Post subject:  Absolutely
I am definitely interested in a new new one. Let me know how much you want and how I can pay it. Thank you.
Author:  Dart270 [ Tue May 15, 2007 5:45 pm ]
Post subject: 
If you have not done, I highly suggest adjusting your valve lash.

Lou
Author:  mszauner [ Tue May 15, 2007 6:31 pm ]
Post subject:  Hydraulic Lifters
I forgot to mention that the engine in there is newer than the car. It had this one in when I bought it. According to the block numbers, the block is around 1982 and so are the heads. It has hydraulic lifters. I had the heads redone a couple years ago and had solid valve guides put in. At that time I also replaced the lifters, pushrods, and rocker arm assembly. Thanks everyone!!

To the person who asked about the dashpot. It is a diaphragm device that is supposed to keep the car from stalling if you suddenly let off the gas and stop. It slowly returns the throttle to the closed idle position. Some later years I believe they actually had vacuum and electrical dashpots that more actively controlled the return to idle.
Author:  Wizard [ Wed May 16, 2007 9:06 am ]
Post subject:  Dashpot....
mszauner
Quote:
To the person who asked about the dashpot. It is a diaphragm device that is supposed to keep the car from stalling if you suddenly let off the gas and stop. It slowly returns the throttle to the closed idle position. Some later years I believe they actually had vacuum and electrical dashpots that more actively controlled the return to idle.
Yes, In fact on carbureted car with spark control computer, this can be either vacuum valve or solenoid itself and holds rpm 200rpm more and computer HOLDs there till car completely STOPPED then it either hold there for long time or a second. High idle to base idle switch over is sudden, HMMM-putt putt putt. :roll:

The weber I'll be putting in will not have this solenoid, so I need to know what cars that is equipped with dashpot so I could order this? Thanks.

Preferably the one a stud with nut saucer shaped unit.

Cheers, Wizard
Author:  ceej [ Wed May 16, 2007 9:28 am ]
Post subject: 
When engine is warm only? How much signal is getting to your EGR at idle? It shouldn't open at idle, and runs through a temperature operated vacuum solenoid in either the Radiator or somewhere on the cooling system.... Disconnect the vacuum line at the EGR and plug it off. Does that help?

CJ
Author:  mszauner [ Wed May 16, 2007 11:11 am ]
Post subject:  EGR Off
I actually have the line plugged there. I was using manifold vacuum because I could not find a good hockey puck. It was routed through the temp sensor. I realized that was not good so I just plugged the line to the EGR and left it there. I will double check to make sure it is fully closed and no vacuum getting to it. We do not have the tailpipe test in Texas for early cars but they require the stuff to be on the vehicle. Real bright.

I found a generic dashpot from NAPA. It is not one that operates on electric or vacuum solenoid. It is passive. I think it was about 11 bucks.
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