58 Corvette with 1987 L98 engine: Running great for months, then died 5 miles from home one day, but restarted after coasting to a stop - drove home with no problem. Four day later, again about 5 miles from home, started coughing through the intake and sputtering (just like earlier) - eventually died after turning around to head back home. Waited 40 minutes restarted but hardly ran – had to call a tow truck - embarrassing. Once home the car restarted - barely ran. No codes were thrown. Vacuum is good at 15 - 17". Checked compression and it was all around 120-130 PSI. Later started and it was smooth and solid - went for test ride and performed well. Stopped at a neighbors about 300 yards from home - spent maybe 3 hours - went to drive back home and barely made it back. Engine would run right for a few seconds and then start sputtering and backfiring. Thankfully it ran strong for a few seconds to get me up my driveway and into the garage. The above happened before summer heat set in here in AZ so the car has been on jacks all summer. A few days ago I started it up and it ran just fine. I let it idle for maybe 10 minutes occasionally rapping the throttle and all was good. Then the next day it ran like crap. Just like the description above – coughing and sputtering. I could keep it running by constantly feathering the throttle but once I stopped it died while back firing through the MAF meter. I could never get the RPMs past maybe 700. Disconnecting the connector to set advance made the engine run worse. The TPS is smooth in its output voltage. Still no codes, suggestions please.