I have a 97 3500 CTD 5 spd / 3:54 <br>this truck is used for carring a 9.5 Honey Camper(2800 lbs loaded) and towing my 24 ft Enclosed Race Car Trailer(8000lbs loaded) and a 12ft Enclosed Dirt Bike Trailer(2500 loaded)<br>when driving back this past weekend from Dirt Ridin,i noticed that the IDLE RPM was down to around 600 to 650rpms(was @850 rpm).<br><br>What could be the major cause of this malfunction?<br>The engine is stock ,i use all Amsoil oils and filters, bypass system too.<br>The exaust is not factory,has Dynomax Race Bullet muffler<br>and all 3&quot; pipes front to back,cat is gone.<br>Seems real sluggish taking off too when loaded.<br>Last fuel milage check was 16 mpg towing bike trailer and car trailer on the Wiz Way@68-70 mph (no camper)<br><br>Thanks <br>hope someone can help on this <br><br>Scott<br>

 

Off the top of my head (fingers), I suggest that you first:<br>

• check the throttle cable for fraying near the bell crank
• check the timing
• check the fuel and air filters (do this second.

<br><br>Good luck!

 

You probably just need to set your idle stop to bump it up a little. RamminOn set mine a little over a year ago and it has now decided it wants some attention again. With the air conditioning days now here (85+ temp AND humidity) the idle in gear is back below 750 and stumbles on letting off the gas. Apparently the head on the stop &quot;wears in&quot; a depression so you may find that a little adjustment to the screw gives a big bump in idle speed. Best to use an optical tachometer (if you can find one) or just set it so the tach needle is just above the mark below 1000 (on a 96 tach face, 97 may be different).<br><br>Not difficult to do. Have fun. Locking nut is 10mm if I remember correctly.

 

Are there any other symptoms such as prolonged cranking upon a cold start??? The spring in the overflow valve may have broken which may explain the sudden drop in idle???

 

Given your symptoms of low idle, poor fuel mileage, and loss of power my suggestion is to check your timing. The factory nut was not set to high enough torque specifications, and will eventually allow the timing to slip back pretty badly.<br><br>When you retime go at least 3 degrees faster than the recommendation on your CPL plate, you will see much better fuel economy, and think you have a hot rod!