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#1 |
Senior Member
![]() Join Date: Mar 2014
Location: Toano, VA
Posts: 874
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Sniper EFI + Dual Sync - No Spark (was a driving truck)
On Tuesday, I went out to start my '67 and it would not start at all. Cranks over, seemingly strong, but no spark - not even a slight kick off.
So I will lay out all the information I have: ISSUE: no spark at all when cranking Base info; 1967 C10, 350 V8 / 700R4. Sniper 1, Dual Sync distributor. Boyd Fuel Tank with in-tank fuel pump. New American Autowire full harness. Optima red top battery (dual post as Holley suggests). Handheld data (when cranking): -Fan 1 & 2 - OFF -AC Shutdown - OFF -CTS, *F - 98 -IAC POS% - 58 -AFR, A/F - ranging from ~15.2 - 14 -Battery Volts - ranges from 10 volts (millisecond at 9.8) but seems to show consistently 11.2 volts (when cranking) - WHEN THE KEY IS IN THE 'ON' POSITION, NOT CRANKING, BATTERY IS 12.3V -RPM - 140-148 -CL Status - OpenLP -Learn Status - NoLearn Testing done: -Inline tester on coil wire to cap - no spark when cranking. -Pulled white wire as per diagnostic tree provided on the dual sync, grounded white wire, inline spark tester shows (seemingly strong) spark. -Checked fuses - nothing blown. -Checked connections, pins, crimps, no issues, burns, loose connections or melted connectors noted or seen at this time. -Checked inside distributor - no burning or damage noted -Replaced with good ignition coil - no change -Tested for power at the positive wire to ignition coil on a test light - tests good Background information: -This was a running truck the day prior, ran good and quite solid I might add. -I did have an issue on the way home the last time I drove it, the truck randomly died without event, and I coasted to the side of the road. Smelled fuel. Inspected under/around truck, no leak, truck restarted and ran fine. The key was left on during the coasting I did, and AFR went super lean (I suspect the Sniper thought it was still running so it was still recording). Never lost electronics (radio, headlights, dash) - I was still in learning mode, as the truck just got to running in June, and this is a Sniper kit that had never been run, I bought it back in '21 with hopes the truck would be on the road earlier than now. - I replaced the oxygen sensor the weekend prior due to AFR going rich when in overdrive and throttle applied. -I had noticed for a few weeks, when the truck is at operating temperature, the IAC will sometimes surge up to 50-60% randomly and try to 'push me through a stop sign' when stopped. It would almost sound like a camshaft surge, to liken it to something. Tasks I performed when installing the Sniper + Dual Sync combination: -Sized alternator through American Autowire with my given accessories. -OHM'd each plug wire after building -Referenced all wiring diagrams - NEVER guessed at wire placement, always consulted tech or a known good shop -Power & ground directly to battery -Kept all wiring from RFI potential areas -12v crank wire to a 12v crank source (as confirmed by American Autowire tech) -Shielded all wiring subject to head with either Earls heat shielding or other heat resistant sleeving -Visually checked for fuel at throttle body -Can hear fuel pump prime/run when key is actuated, sounds normal as it did My suspicions I am trying to either disprove or confirm: -Either a bad ECU and I am lucky I made it home with hot dinner, so far I do not see any at home tests for the ECU -A battery with low cranking voltage. At this time, this is all the information I have. Keep in mind, this truck cranked, ran and drove for multiple weeks before this issue occurred.
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"Sometimes I do serve as a good bad example. Glad to be of service." My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809 |
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efi, holley, no spark, sniper |
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