RE- 86-2.8 TBI,
Drove to the airport & left the truck for a week. When I started it upthe engine wasmissing a little, not too bad. However when I hit the freeway and 4th gear (automatic) the miss became a full blown coughing with an occasional obvious backfire. The problem is not noticable during idle or at high RPM, only when it's under a load. The RPMsat idle are running very high, even after operating temp is reached. I should point out the just prior to this my I left my key on over night and it needed a jump. However I drove 80 mileswithout any problem before parking it for a week.

Any advise would be appriciated!

 

Is your truck fuel injected? i figure it's fuel or spark, how does the underside of your dist. cap look?

 

IF YOU HAVE A MISS UNDER LOAD; THIS USUALLY POINTS TOWARD IGNITION (IE: SPARK PLUG WIRES/ SPARK PLUGS DISTRIBUTOR CAP AND OR DISTRIBUTOR ROTOR.
A MISS AND HIGH IDLE, WILL ALSO CLUE ME IN AS AN ENGINE VACUUM LEAK.
Last but not least; If you're vehicle sat,Condensation could have built up in the gas tank and you may just need to run this tank down to around a 1/4 tank and refill to full and change the fuel filter.
Hope this helps and sorry about all caps up there