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Discussion Starter #1
Went out for a New Year's Day cruise, and filled up with gas. After I filled up, the car wouldn't start. The engine cranks, but I don't appear to be getting any spark.

I had the battery load tested, and it passes (rated for 450 CCA and measured at ~600 CCA). The battery (3yo Optima Yellow Top D51) is fully charged at 12.6 V.

I'm getting 12.5 V to the coil (TFI type) during run, as expected. However, at crank the voltage drops to ~10 V.

When I put jumper cables from my Jeep to the roadster, I get 14.5 V to the coil at run, and it drops to 12 V at crank.

When the engine cranks, I see on the Holley hand-held unit the RPMs are ~180-190.

Anybody got any ideas what I should test next? Any leads I should follow?


John
 

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Since no one else has answered, I’ll give it a shot and start the ball rolling.

I suspect the coil or wiring to it. You have rpm sensed by the EFI, so your distributor pick up is good. That leaves the coil, ignition box(if used) and the wiring in between. Use one of your plug wires ( I usually use #4 or 8 because they’re the longest ) and a spare spark plug grounded against the engine or frame and get someone to try and start the engine to see if you have spark. You could get your wife to hold the spark plug while you turn the engine over. If she jumps and calls you bad names you’ve probably got spark.😇 Note this test is usually only good for one try so save it for when it’s really important!

Safety note: don’t take a spark plug out of the engine for this test. Since you’ve been trying to start with no success you may have a lot of unburnt fuel vapour in your cylinders and exhaust just waiting for a spark to set it off.

Hope This Helps

Norm
 

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Only thing I can ad is also do the plug test to the coil by itself. Pull the coil wire from the distr cap and hold it near a ground to see if there is spark.
 

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Discussion Starter #4

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Discussion Starter #5
Boydster on the other forum sent me an Accell TFI coil, an MSD TFI unit, and a plastic bag with the mounting screws in it. That was very generous & I plan to pay his kindness forward.

I swapped out my MSD coil for the Accell & tried starting the car. No joy. Next, I bought an in-line spark tester (https://smile.amazon.com/gp/product/B0002STSC6/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1). Basically a glass tube with a gap between the conductors. Tested both coils but couldn’t see any spark, plus car didn’t start.

Thinking ambient daylight was washing out the spark’s light, I tested both coils last night in the dark. Got spark with both coils AND the car ran with both coils. That seems to exonerate the battery, the coil, and the wire from the coil to the distributor, right?

So...now I’m thinking (1) bad connection on the control wires to the coil, (2) bad ground to ECU (it controls the firing of the coil), (3) intermittent failure of the TFI unit, or (4) failing distributor (I seem to recall reading how a cracked distributor housing caused an intermittent no-run condition).

Does anybody have anything else I should add?


John
 

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The ecu was recording rpm during cranking. To me this eliminates the distributor pickup and most likely the ecu ground (pretty sure it can’t sense anything unless it’s grounded). A cracked distributor cap can cause ignition issues but it would be pretty obvious. Most likely an intermittent bad connection in the coil wiring. “Intermittent electrical fault” are my least favourite words when it comes automotive repair. Good luck!
 

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Went out for a New Year's Day cruise, and filled up with gas. After I filled up, the car wouldn't start. The engine cranks, but I don't appear to be getting any spark.

I had the battery load tested, and it passes (rated for 450 CCA and measured at ~600 CCA). The battery (3yo Optima Yellow Top D51) is fully charged at 12.6 V.

I'm getting 12.5 V to the coil (TFI type) during run, as expected. However, at crank the voltage drops to ~10 V.

When I put jumper cables from my Jeep to the roadster, I get 14.5 V to the coil at run, and it drops to 12 V at crank.

When the engine cranks, I see on the Holley hand-held unit the RPMs are ~180-190.

Anybody got any ideas what I should test next? Any leads I should follow?


John
ANY ERROR CODES
 

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Discussion Starter #9
I continued trouble shooting today for all of about half an hour. I re-installed the original MSD coil, cycled my push button start to run, heard the fuel pump kick on for 5 seconds, and then successfully started the car. It ran for a little less than a minute & then died. While running, I got a loud pop from the right side pipe, but it ran for a couple more seconds before dying.

I started the car again; this time it ran for about 30 seconds & then died. No popping from the side pipes.

I tried starting the car again; this time it behaved like it had no spark.

Thinking it was the TFI module, I replaced it with one that Boydster gave me. It was pre-greased with clear goo, so I just removed & replaced the old one.

This time the fuel pump didn't kick on when I cycled the push button start to run. With no point in trying to start with no fuel getting pumped, I walked away.

This problem has me scratching my head & it don't itch!


John

Norm B: I'm inclined to agree the distributor is working correctly.
davekp: I've read the TFI modules fail frequently, but my original one only has ~3000 miles of operation.
gary715andy: No error codes from the Holley Terminator ECU; everything it's monitoring looks normal.
 

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Did you try to refresh you tune in the ECU? If you saved it, try re-installing the tune. Also, do a datalog (set up before cranking) and see exactly what the ECU is telling you. The Holley will not engage the fuel pump without a tune or reference of a tune installed. If you have a fuel transducer installed, the LCD screen will read fuel pressure as will a live gauge if you have one installed.
 

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Discussion Starter #11
So here's the latest.

I read on the Holley forum where disconnecting the battery for ~20 minutes seems to clear all manner of ECU problems. So I disconnected the battery a couple of days ago.

Today, I reconnected the battery & cycled the push button start (PBS) from OFF to ACC to RUN. At RUN, the fuel pump kicked on for ~5 seconds as expected & then shut down. Encouraged that my fuel "problem" had healed itself, I verified the Coolant Temperature Sensor, Manifold Air Pressure, Manifold Air Temperature, Throttle Position Sensor, & Battery indications were nominal; they were. I set the hand-held unit to record data, & cycled the PBS to CRANK. The engine started right up. I let it idle for ~5 minutes, then took it for a quick spin in my neighborhood. I mostly ran it ~2000 RPM in 2nd, with occasional bumps to 3000 RPM and a jump to 3rd. After ~20 minutes of run time, I pulled into the garage & shut it down.

PRO TIP: The Holley data logging software does NOT record data if you simply shut off the engine! You have to use the hand-held unit to stop data logging - then shut the engine down. I failed to do this, and so lost all my cold start data.

After ~30 minutes, I tried to start the car again. I cycled the PBS to ACC & then RUN. As expected, the fuel pump kicked on for ~5 seconds, then shut down. I started data logging again, and let the car idle in my garage for a couple of minutes. I then tried to rev the engine to 3000 RPM, but it wouldn't hold (despite the throttle position sensor showing I was holding steady at 3%). While I was revving the engine, I got a coupe of loud pops from each side pipe. I then let the engine idle for another minute or so, & shut it down. This time, for whatever reason & despite failing to manually stop the data log, I was able to capture some data.

To me, this exonerates the TFI (thanks to Boyd, who provided a now-known good module) and the PBS. It's looking more and more like an electrical problem in the Holley system.


John
 
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