Engine miss when warm
Thread Starter
Intermediate
Joined: Nov 2004
Posts: 28
Likes: 0
Engine miss when warm
I have a 94 LT! that runs fine except when it gets warm/hot I get a miss when accelerating. For instance, when I pull away from a stop light the engine will cough once until I get up to speed then it runs fine. Any suggestions? It doesn't do it when cold. Plugs, plug wires, injectors?????????
Pro
Joined: Oct 2007
Posts: 737
Likes: 51
From: Reno NV
When was the last time you changed your spark plugs and wires ? That will give your engine miss fire. Also the stock optispark is piece of garbage that could give you miss fire too.
Mine will get the miss too when it warms up. Seems to only do it when I accelerate all the way in high rpms. But I'm getting ready to do spark plugs, wires, msd optispark, water pump and coolant hoses.
Mine will get the miss too when it warms up. Seems to only do it when I accelerate all the way in high rpms. But I'm getting ready to do spark plugs, wires, msd optispark, water pump and coolant hoses.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
The key word here is when it warms up. That is a classic opti symptom. You can cruse easy and be OK. But once you load the engine and add gas, it will kick or buck. Drop it to a lower gear and problem seams to fade away. Could even have a slight wondering idle. If you have these problems is probably an opti.
The plugs and wires will generally act bad when the engine is cold also. And for me, the data just doesn't say ICM or injectors.
The plugs and wires will generally act bad when the engine is cold also. And for me, the data just doesn't say ICM or injectors.
Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
It could be all or none of the above. Use the diagnostics in the FSM to nail it down. Obviously the first thing to do is pull the codes.You did not give much history on the car to work with. Milage,maintenence, any previous repairs,any fluid leakage, any engine washing done in the recent past?This is one of those things that may need to get worse to get a good diagnosis if no codes exsist.
pcolt makes a good point but ICM's do exhibit some strange issues when warm. Optis do not have to be warm to run crappy.When cold the car is in open loop and once it warms up the O2's take over fuel management. It all depends on what "warm" is and how soon it starts doing this so you must be very specific about the timing and temp of the problem and the more info the better.
pcolt makes a good point but ICM's do exhibit some strange issues when warm. Optis do not have to be warm to run crappy.When cold the car is in open loop and once it warms up the O2's take over fuel management. It all depends on what "warm" is and how soon it starts doing this so you must be very specific about the timing and temp of the problem and the more info the better.
