HELP! Truck Idles Low and then Stalls after Warm-Up
#1
HELP! Truck Idles Low and then Stalls after Warm-Up
I just installed new stainless headers, 3" exhaust, high flow cat, flowmaster super 40, and o2 sensors. While I was doing the headers, I replaced both front fenders because they were rusted. I also did some welding because a few of the header bolts broke.
Now, after I got the truck all back together, the truck will start up and idle real low(300-500rpm) and when the truck gets to operating temperature, it stalls.
At first I thought it was a heat issue, so I wrapped the headers, fuel lines, and starter. Didn't help.
The check engine light was also on (P1687 - No MIC Bus Message Received and P1391 Intermittent Loss of CMP or CKP)
So I checked all the bus wires and camshaft and crankshaft position sensors, and they checked out fine. The check engine light also went out after checking everything.
I took it for a test drive and the ABS light and Brake light came on and the speedometer was stuck at zero until I got to 20-30MPH. And then it eventually stalled, unless I kept on giving it gas. So I replaced the Vehicle Speed Sensor and ABS Speed Sensor. Didn't help either. Speedometer is still out of calibration.
Other things I also tried was replacing the Idle Air Control Valve and cleaning the throttle body.
I also thought that since I did some welding, I might of fried the MIC Computer (Instrument Gauge Cluster), so I swapped it with a junk yard one, and it still stalled.
Battery is reading 12.15 volts and 13.8 volts when running.
Also, my uncles scanner tool can not access data on the truck, like it used to before this all happened.
I am tired of putting money into replacing parts. Any help will be appreciated.
Now, after I got the truck all back together, the truck will start up and idle real low(300-500rpm) and when the truck gets to operating temperature, it stalls.
At first I thought it was a heat issue, so I wrapped the headers, fuel lines, and starter. Didn't help.
The check engine light was also on (P1687 - No MIC Bus Message Received and P1391 Intermittent Loss of CMP or CKP)
So I checked all the bus wires and camshaft and crankshaft position sensors, and they checked out fine. The check engine light also went out after checking everything.
I took it for a test drive and the ABS light and Brake light came on and the speedometer was stuck at zero until I got to 20-30MPH. And then it eventually stalled, unless I kept on giving it gas. So I replaced the Vehicle Speed Sensor and ABS Speed Sensor. Didn't help either. Speedometer is still out of calibration.
Other things I also tried was replacing the Idle Air Control Valve and cleaning the throttle body.
I also thought that since I did some welding, I might of fried the MIC Computer (Instrument Gauge Cluster), so I swapped it with a junk yard one, and it still stalled.
Battery is reading 12.15 volts and 13.8 volts when running.
Also, my uncles scanner tool can not access data on the truck, like it used to before this all happened.
I am tired of putting money into replacing parts. Any help will be appreciated.
#3
#4
#6
#7
I'm thinking crank sensor. A bad one does just what you are saying, stalls when warmed up. I see you replaced o2 sensor. And what brand parts are you buying to replace the sensors ? And did you disconnect the negative battery cable when doing so?
Last edited by zman17; 07-22-2013 at 03:00 PM.
Trending Topics
#8
#9
But why would all of a sudden, it goes bad? I'm wondering if it is just the wiring has a short or something, but it will take forever to find it.
The o2 sensors I got are Bosch brand. The idle air control valve, speed sensor, and abs speed sensor are all Duralast brand. and yes I disconnected the negative terminal when I installed them.
#10