Runs Rough, stalls, & misfires up to 3,000 rpm. Starts & runs fine when cold – symptoms show-up after a brief warm-up.
Original symptoms were stalling at idle or near idle when slowing down during driving (again ran fine when cold). There was some misfiring or “bucking" during driving, but was minimal and started just before changing the battery. In addition the symptoms would go away after driving for 30+ minutes. No codes were displayed. I changed the battery out (old one tested bad). After installing the battery, the engine ran rough with misfires after warm-up (was fine cold), and eventually would stall. Everything smoothes out just above 3,000 rpm & codes 0171, 0500 & 1391 are displayed.
I’ve owned the truck for a few years and have only put about 2000 – 3000 miles on it, but never had any real issues before now. Frequency of driving is about 2 – 3 times per month and long enough for everything to get well warmed up.
The TB was cleaned out well just after I purchased the truck.
Before embarking on a replacement campaign for IAC, Crank & Cam sensors, & differential speed sensor among other things, do you have a more targeted idea as to what I should start on?
Thanks for the reply.
Fuses all good, harness (as much as I could inspect) looks ok, no vacuum line or fitting leaks, but found the air intake box was not set correctly.
Re-set this and truck runs fine except warm idle. Idles fine cold, but as soon as RPMs drop upon warm-up it stalls. Some accelerator will keep it running smoothly.
I cleared the codes and no new ones are indicated after keeping the truck running for a bit.
Would this narrow it down to the IAC? Reminder - new battery was just installed.
have the same problem?
Tuesday, January 5th, 2010 AT 9:03 AM