1987 nissan pathfinder, desperate

any codes now or then to mull over? what was the original problem? i will add that you are not alone in your frustration. these nissans and villigers and quests all suffer from very similar problems. people have stories of hundreds of dollars spent and no results. there are a few winners though. could be as simple as cleaning the optical sensor in the distributor! but if yours is new thru and thru i guess that would be out. another had the speedometer replaced which routes the speed sensor info to the computer! how odd is that? but yours is an older model so not a lot of interest put forth unfortunately. maybe a long and careful search on the net thru all the stories would help?

Have the compression checked. Seems the engine is running below par.

If problem only occurs when engaged to forward gears and not when reversing, check for vacuum leaks. When engine tilts one way, there is none or minimal vacuum leaks. When engine tilts the other way, vacuum leaks increases and this would result in stalling.

Check all vacuum hoses for cracks, especially the brake booster hose if brake pedal seems stiff.

Is it a 4 or 6 cylinder, in any case while the engine is running, with the parking brake set. etc... and paying close attention to any moving parts while working under the hood start moving the wiring harness from the bulkhead head to the engine, there were many cases of bad splices in the ground circuits and broken wires. by gently pushing, pulling and twisting the harness you may get the engine to die. repeating may draw you closer to a wiring problem, that is what is sounds like.