Question about 1991 Chevrolet C1500
There are numerous things that could cause this. Something I do on mine every 6000 miles is get a can of carb & coke cleaner. I start the truck, and rev to 3000 rpms then I spary cleaner directly in to the TBI. This cleans pretty much everything out that has been built up over time. (Truck will try to die when performing cleaning. Keep sparying and up the amount of throttle just enough to keep running.) Now since the truck is a few years old I would next CK the vacum lines. They run all over the top of the engine as most people know but also on your truck they are what run the air vents moving from floor to vent to defrost, and if 4x4 the front axel hub locks. There is a vacum line that runs from TBI to the vacum canister (located on driver side behind head light) Then it runs down beside the radiator to the frame rail then down the frame rail to the cab. This line is mostly metal (just like the metal brake lines) and it seems get holes in it from it rubbing all sorts of ****. Then I would ck the throttle postioning senser, and timing. Also on these trucks the idle will be around 200 to 400 rpms higher in Park or Netural then if in Reverse or Drive. If it does not change more then likely you are having either problems with a sensor in the transmission, or Computer problems. Also if you have a TBI spacer it will rasie your idle most the time. If you dont have a spacer you will also want to try this. (you never know if someone else may of adjusted it) You will need to adjust your idle screw. NOTE: Keep track of exactly how much in or out you adjust this screw. This way it can always be returned to stock.)
Posted on Aug 08, 2008
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Jan 15, 2015 | Pontiac Cars & Trucks
Mar 25, 2013 | 2003 Chevrolet Silverado 1500
Dec 11, 2012 | 2000 Dodge Dakota Quad Cab
Apr 10, 2010 | 1998 Chevrolet Monte Carlo
Dec 07, 2009 | 1994 Chevrolet K1500
Jul 09, 2009 | 1991 Ford Taurus
Jul 09, 2009 | 2002 Land Rover Freelander
Sep 26, 2008 | 1991 Jeep Comanche
Jul 06, 2008 | 1991 Mazda MX-5
Mar 14, 2017 | 1991 Chevrolet C1500
411 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: