NASTF is a cooperative effort among the automotive service industry, the equipment and tool industry and OEMs to ensure that independent automotive service professionals have the information, training, and tools needed to properly diagnose and repair today’s high tech vehicles. Corporate Partner

Old School - GM TBI - Distributor Waveforms

Scott Owner/Technician California Posted   Edited  
Resource
Driveability
1987 Chevrolet V10 Suburban Custom Deluxe 5.7L (K) 4-spd (THM700-R4/4L60/MD8) — 1GNEV16K9HF160206
Stall At Idle
Erratic Idle
Extended Crank Hot

Here are some before (aftermarket performance distributor) and after (New GM stock distributor) waveforms from this erratically behaving Suburban.

Old @ 400 Dist RPM

New @ 400 Dist RPM

Old @ 1000 Dist RPM

New @ 1000 Dist RPM

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diag​.​net/file/f2zomfxa7… ​

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NASTF is a cooperative effort among the automotive service industry, the equipment and tool industry and OEMs to ensure that independent automotive service professionals have the information, training, and tools needed to properly diagnose and repair today’s high tech vehicles. Corporate Partner