1995 Chevy truck Missing under a load.... ugh

[Tim Wurtz]

This one has left me scratching my head, I have a 1995 Chevy K1500 with a 5.7L engine. The problem I am having is the truck is missing under a load. There are a couple areas where I notice this. It seems to always be worse when the truck is at operating a warm temp. While driving down the road and in overdrive and you ease into the throttle the truck really starts missing bad, but when I manually shift it into 3rd to get the rpms up it don't do it then. I notice when I have extra passengers it seems to do it bad also. Sometimes at an idle I randomly feel a missing kinda like a jolt every once in awhile, and also sometimes while taking off from a stop it will miss a few beats too.

 

I would it is not spark plugs, new or old didnt make a difference. The problem doesn't seem consistent with plugs or wires because this is an intermittent problem, and mostly seems to happen while under a load and while it is warmed up.

 

Any ideas out there on this one?

 

BTW this thruck only has 84,000 miles on it.

[getcrunk88]

Try a better coil like an msd that can ignite any air to fuel ratio mabey thats your problem

[ChevyTech007]

Sounds like plug wires to me. I believe thats were I would start anyway.

[bearsclaw2]

I am having the exact same problem I have 172000 miles on mine and as of right now I have replaced the distrbutor, wires, cap and rotor, complete fuel pump and sender assembly, and ignition coil and there has been no change the O2 sensor is also new but that is not related. I am looking at the injectors or the pressure regulator but I don't think they will be the problem I am starting to think the wiring harness may have a problem.

[GM-Tech]

Torque converter clutch? When this problem occurs, LIGHTLY touch the brake pedal without changing the amount of throttle you're applying. This will disconnect the TCC.

 

Otherwise, intermittent or not, wires would be the most likely cause.

[rodram]

to bearsclaw2 and to Tim

 

.... before throwing too many more new parts at these things, I would check the Coolant Temperature Sensor (CTS) located on front top of engine beside the thermostat housing ... when they fail, the engine will run fine when cold but cannot sense that the engine is warm and so the ECM is still telling the injectors to send too much fuel (as if the engine was still cold...) ... then the engine runs too rich

 

.. just another easy thing to check

[asilverblazer]

to bearsclaw2 and to Tim

 

.... before throwing too many more new parts at these things, I would check the Coolant Temperature Sensor (CTS) located on front top of engine beside the thermostat housing ... when they fail, the engine will run fine when cold but cannot sense that the engine is warm and so the ECM is still telling the injectors to send too much fuel (as if the engine was still cold...) ... then the engine runs too rich

 

.. just another easy thing to check

 

Wouldn't this show a cold engine on the gauge as well?