Slant Six Forum
https://slantsix.org/forum/

1979 B100 questions
https://slantsix.org/forum/viewtopic.php?t=53031		 Page 1 of 1
Author:  ziggysl6 [ Mon Aug 12, 2013 11:56 am ]
Post subject:  1979 B100 questions
So i just picked up a 79 b100 with the 225. one of my concerns was that accelerating from a stop up till about 45mph the engine would often shake crazily. so i would nurse it up to speed. i was on the highway for 288 miles and as long as i was above say 55mph. there was no shaking everything ran smooth. also fast acceleration at that speed (55mph +) sometimes did but nothing like at slower speed. as long as i was just cruising, it was smooth. i know nothing of kickdown linkage and what is good or bad as far as looking ath the linkage itself. i do have a factory service manual however it doesnt explain it a way that i completely understand. im not totaly sure thats even the problem. could it be the carb? also the smog pump is seized no belt on it. but i wanted to eliminate it off the van eniterly. i know in my 74 dart i also removed the egr valve. but i dont remember why i did it. the 74 has a super six intake and maybe thats why i did it? idk. however i would like to know what i should remove off the motor for better performance and fuel economy. im sorry if this is alot all at once .
Author:  crater [ Mon Aug 12, 2013 12:36 pm ]
Post subject: 
I would try manually putting the car in 1st and accelerating then 2nd to see if it is related to the transmission kick down or a specific gear. This takes any of the automatic stuff out of the equation.
Author:  ziggysl6 [ Mon Aug 12, 2013 1:18 pm ]
Post subject: 
what exactly am i looking for when i do that? manually putting in 1st gear and then shifting in 2nd. if i do that and acelerate if its linkage the problem should not be there? and if its still there then maybe carb accelerator pump or something?
Author:  Reed [ Mon Aug 12, 2013 1:59 pm ]
Post subject: 
Shaking crazily on acceleration could be a number of things.

My advice to you is to first do a thorough tune-up on your engine. Start with adjusting the valves and verifying the timing. Then I would inspect your carburetor and make sure all the settings are correct.

Once you have verified those basic things, then I would move on to looking at the transmission.

To adjust the kickdown linkage:

(1) make sure the engine is off
(2) make sure the throttle is completely closed and the fast idle screw is not holding the throttle open. If the fast idle speed screw is resting on a step of the fast idle cam, move the fast idle cam until only the curb idle speed screw is touching the stop.
(3) loosen the bolt on the clamp on the end of the kickdown arm on the transmission. Make sure the clamp slides freely on the kickdown linkage.
(4) push the arm as far forward as it will go.
(5) tighten the bolt on the clamp.
(6) smile at having adjusted the kick down

A shudder on acceleration could very well be worn out clutches in the transmission. I have seen transmission shudder caused by worn out front and by worn out rear clutches. Further, 1979 was near the first year of the lockup 904 transmission and was notorious for having problems with the torque converter locking up prematurely or not unlocking. It could be your torque converter is locking up too soon causing a shudder. Chrysler actually put out a retrofit kit to deal with the torque converter lockup shudder problem. The kit was noting more than a stiffer spring to be installed in the valve body that would raise the lockup point of the torque converter.

In any event, you are going to have to spend some time getting familiar with your FSM and using the diagnosis sections. Luckily the 904 is a very simple and cheap transmission to rebuild. I rebuilt three for under $200 using all new parts.
Author:  crater [ Mon Aug 12, 2013 2:09 pm ]
Post subject: 
Quote:
what exactly am i looking for when i do that? manually putting in 1st gear and then shifting in 2nd. if i do that and acelerate if its linkage the problem should not be there? and if its still there then maybe carb accelerator pump or something?
Well you'll know if it is kickdown related if it doesn't happen when shifting manually because the kick down is not being used when you're locking it in first.

As said above you'll need to go through and verify all the basic tune up items to really identify anything.
Author:  ziggysl6 [ Tue Aug 13, 2013 6:08 am ]
Post subject:  ???
"However, if your car is a '75 or newer model with a catalytic converter, don't remove or disable the air injection system. If you do, the catalyst will overheat, melt down, and block off your exhaust flow (and perhaps start a nice fire). "

smog pump is seized. is it possible that i has melted my catalyitic converter and is restricting my exhaust.
Author:  Rug_Trucker [ Tue Aug 13, 2013 7:39 am ]
Post subject: 
If the cat is plugged you can feel the flow with your hand while someone revs it. My 360 had a partially plugged converter and it was glowing red.

The air pump not working won't kill a cat unless you are in a bad state of tune super pig rich. Even with the air pump working it killed the cat. Why? The blow by was so bad on the old motor the breather tube from the crankcase was plugging the air filter with oil!

If the cat is plugged shove a steel bar in there and whack it with a hammer, leave the empty case. Mine actually cracked and rattled for a while on it's own. When I changed the muffler there was nothing is the case! :lol:
Author:  Reed [ Tue Aug 13, 2013 10:27 am ]
Post subject:  Re: ???
Quote:
"However, if your car is a '75 or newer model with a catalytic converter, don't remove or disable the air injection system. If you do, the catalyst will overheat, melt down, and block off your exhaust flow (and perhaps start a nice fire). "

smog pump is seized. is it possible that i has melted my catalyitic converter and is restricting my exhaust.
Yes. The catalyst will degrade and start blowing out the back of the converter in chunks. These will land in the muffler or get tangle up in the catalytic converter housing and can block it up.

My advice is to replace the catalytic with a three-way high-flow converter, the muffler with a Walker quiet flow, and repair the air pump.
Author:  Rug_Trucker [ Wed Aug 14, 2013 8:13 am ]
Post subject: 
My cat guts were no where to be found.

I didn't know you could get new air pump stuff. No emissions to pass? Find a different place to spend your time and money.
Author:  Reed [ Wed Aug 14, 2013 8:32 am ]
Post subject: 
You can still get remanufactured air pumps for a 79 slant powered van on Rockauto. Check valves too.
Author:  ziggysl6 [ Sat Aug 17, 2013 10:03 pm ]
Post subject: 
turns out I have a bent pushrod and one that slipped out.
Author:  Reed [ Sat Aug 17, 2013 10:26 pm ]
Post subject: 
That will definitely hurt economy and performance.
Author:  wjajr [ Sun Aug 18, 2013 4:51 am ]
Post subject: 
Now you gut to ask you’re self one question; was it running on four or five cylinders?

Lt. Callahan
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/