The Stovebolt Site Forums The Parking Lot Big Bolts 653 not idling down and fuel lines.

My 653 in my 1966 C70 Chevy will Idle down fast to about 1100 rpm from a higher speed then holds there at 1100 +or - for 1 sec then goes to idle. Is this normal? I can not move the lever to idle its being held in side the governor until it lets it go to idle. I have the linkage off so its not binding.

Also what should it Idle at? And where is the Idle adjustment at I believe its under the cover with the small two bolds holding it just same as me 353? Can I just adjust the idle with out adjusting any thing else?

And the fuel filters, the secondary is on the motor like it shows in the photos in the operators manual but what I can not see is where the primary filter should be?
Right now its on the rear of the truck next to the passenger side fuel tank . I think it should be closer to the fuel pump nearer the motor.
And the return line is going to the bottom of the fuel tank. The fuel pick up is coming off the top of the tank it must have a pick up tube. I would like to return the lines and filter to the stock locations if there not right now.

Parts needed:
Drive side front fender or the front half cut off a good fender.
Glove box light cover on the out side of the glove box door.
Air tank check valve the one screwed into the top of a duel compartment tank , Need the part that seals the air from thak to tank the small plastic or? puck that goes under the spring.

Brian

Brian,

Your 6V53 may have a gummy governor, I am just about finished cleaning and rebuilding the one on my 4-53T, hope to have it back on tomorrow. At least on the inline engines the top governor housing gets very little to no oil, and will condense water and get gummy and rusty, causing the symptoms you describe. (later model inline governors have an oil line going to the top to help with this problem)
Take the governor off, apart, and clean it all up and reassemble with new parts where needed, check the governor weight pins for wear as well. At the very minimum remove the idle speed adjustment cover, then with a spanner wrench remove the high speed spring retainer, and clean all the parts that fall out. Also check for the shaft in the top cover being worn, and don't forget to grease it every now and then. If it is worn best to ream it out and install a bushing (9/16" x 7/16" x 1.25"), as otherwise the new top cover is about $150, and make a new shaft, or spend $60 on a new one.

I don't think your hanging idle is an adjustment problem as much as it cold be a sticky or worn governor problem. But none the less, a proper tuneup according to the book would be an easy fix if that's all it is.

Idle speed should be 500-600, depending on application, so if you have an air compressor you want to be on the high side of that range.
The idle speed is under the small cover same as your 3-53, to adjust it the book says first back the buffer screw out about 5/8". Set the idle speed, adjust the governor gap, adjust the rack, set the max speed, reset the idle speed, and finally adjust the buffer screw. That's the readers digest version, best to get the service manual out and go over all 6 pages in the tuneup section for your governor, section 14.3.2.

Primary filter (suction side of pump) is usually on the frame by the tank in a truck application, your situation sounds normal.
Return line needs to be submerged where it enters the tank, helps to reduce fuel draining out of the system when sitting and being hard to start. Obviously fuel pickup needs to also be near the bottom, but not beside the return, as the return is warm, and you want cool fuel at the pickup.

Do you have a good service manual yet? I like the later version that is in two separate white 3 ring binders.

Grigg

Some good info thanks. I have a detroit service manual on CD.

All I can do is guess about why the motor is yellow now but some green paint does show under the yellow. I think it been rebuilt some time in its past. The governer body is the only part not painted so I guess it been replaced or rebuilt. I will take the cover off and look in side to see if what it looks like.
On a diesel foram a long time DD machanic says to try backing out the buffer screw some.
Over time I will go over it by the book and set it up right.

Here is a video of what it doing.
YouTube 653 Idle problems

Brian