Saab84mw
OBS Enthusiast
K2500 suburban 454 vortec misfire mainly under a load and worse with the A/C on.
Here is what I’ve done so far just recently with in the past week I put a MSD cap rotor and coil on the truck trying to fix the misfire issue was told that the original caps were made out of a different material and MSD cap would be better.
Truck ran Better for the next three days then started misfiring again.
Within the past five years have replaced the injectors with fiveomotorsports injectors also replace distributor crank sensor, fuel pressure regulator, fuel pump and recently replaced map sensor And O2 sensor that was determined to be bad by a scan tool From a friend who had one.
The catalytic converter‘s have been removed and the O2 sensors are in the stock location in the pipes.
Seems like every time I work on this truck and replace parts it will run good for a few days and then start running bad again truck has 216,000 miles on it when it is running good it runs pretty strong.
Today I noticed that the misfire starts at about 1500 RPMs up to about 2500 rpm’s when accelerating.
I have been fighting this issue for a while I’ve had this truck for about 14 years bought it when it had 144,000 on it I was running strong when I bought it.
I just want to try to figure this issue out before I put a remanufactured engine in it and the transmission and transfer case has already been done.
Thanks and any help would be much appreciated.
Here is what I’ve done so far just recently with in the past week I put a MSD cap rotor and coil on the truck trying to fix the misfire issue was told that the original caps were made out of a different material and MSD cap would be better.
Truck ran Better for the next three days then started misfiring again.
Within the past five years have replaced the injectors with fiveomotorsports injectors also replace distributor crank sensor, fuel pressure regulator, fuel pump and recently replaced map sensor And O2 sensor that was determined to be bad by a scan tool From a friend who had one.
The catalytic converter‘s have been removed and the O2 sensors are in the stock location in the pipes.
Seems like every time I work on this truck and replace parts it will run good for a few days and then start running bad again truck has 216,000 miles on it when it is running good it runs pretty strong.
Today I noticed that the misfire starts at about 1500 RPMs up to about 2500 rpm’s when accelerating.
I have been fighting this issue for a while I’ve had this truck for about 14 years bought it when it had 144,000 on it I was running strong when I bought it.
I just want to try to figure this issue out before I put a remanufactured engine in it and the transmission and transfer case has already been done.
Thanks and any help would be much appreciated.