The truck has 196,000 miles. (I am the original owner). It starts to surge/stumble upon rapid acceleration.
Gentle acceleration seems not to be a problem. It has stalled once or twice and had difficulty restarting. Two shops have not found the problem. The last shop recommended a scattershot approach (replace the coils and igniters, replace the distributor and the electronic carburetor. As these are not inexpensive parts, I am trying to narrow down the problem area. One of the coils has a very small spark compared to the other. Could this be the issue? This problem started several months ago and has become worse over time. Any ideas?
In my opinion it is a fuel delivery issue, gentle acceleration OK Hard accel NG! Check pump pressure Carb model should be 7-9 psi.
September, 10, 2007 AT 5:16 PM
I should explain that the surge/stumble description may not be a good explanation. The symptom seems to be
rhythmic. In other words, during rapid acceleration the
power loss is sort " on" " off" " on" " off" in a pattern so to
speak. Very consistent. I also notice the smell of unburned gas.