High idle w/new spring.

[Rebel Ram]

I just put a 3200 RPM spring in my 93 and adjusted as follows. Star wheel bottomed. Smoke screw flush with jamb nut. Turned cone to max depth. Two turns in on the full fuel screw. At start up the idle was high as I expected it would be. (It did this on my 92 and it was fine) But when I tried to turn down the low idle adjustment it had no affect. So what I had to do was back off the full fuel screw to lower the idle.

I had no hint of a runaway. Revs quick and settles down just as fast. I would like to get all the fuel I can from a stock pump but am wondering what is up with the high idle and losing adjustment for full fuel. Any advice?

 

[Greenleaf]

Learn YOUR Pump

You need to understand the operaton of the pump linkage and trucks throttle linkages and how they operate together. You will notice that when you install the spring and or turn-up the fuel rate your (slow) idle speed will increase.



By backing off the (slow) idle screw you have simply turned the screw backwards and nothing more will occure simply becasue there is no slack in the other dajustment(s)



You will have to readjust the throttle rod and then readjust the slow speed screw TOGETHER. One effects the other. If you have an auto transmission then you also have to adjust the TV cable. All three must be readjusted if you care about what your end result is. Some can simply get by with turning the sloow screw backwards with out adjust the other two linkages but then they are not perfroming the operation properly.



You do not want any slack in the linkages. If you do, you have lost throttle travel and will make a big difference in top end power.



That is something the big HP guys don't want you to know LOL Also, (hint hint) never, never shorten the governor spring and rework the pumps throttle lever to obtain 3,800/4,000 rpm's ROFLMAO

 

[Rebel Ram]

Yes. This was with the links off. The lever stop was contacting the low screw. Weird.

When you say readjust throttle rod, you mean the linkages, Yes? Not the throttle shaft?

 

[Greenleaf]

The speed will slow down. I have installed a couple springs in my day and the procedures used to obtain the desired slow idle speed have varied.



The most "involved case" I encountered was cutting off the throttle lever stop arm, welding it back onto the throttle lever in a more rearward position. On another pump, the arm had to be rotated on the throttle shaft one notch to allow for an acceptable slow idle speed. This resulted in obtaining the desired slow idle speed adjustment.



However this was encountered when modifying the 3200 speed spring (cutting it shorter) . I have never had to modify the lever to obtain an acceptable slow speed setting simply by installing a 3200 rpm spring. Your slow speed screw **** should**** back off enough to allow the engine to reach a slow idle of 750/800 rpm. If not then you have the fuel screw in too far and will have to modify the lever or back off the fuel screw a 1/2 turn or so.

 

[BushWakr - RIP]

Would I be presumtious if I mentioned the throttle shaft indexing ??..... That will give you a similar symptom... ...



bp...