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Newbie can't start a Seven


jordway

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Install one of these temporarily to verify coil discharge while cranking. If the voltage drops too much due to the starter load, batt capacity, or poor connections, the ignition system won't operate:

https://shop.advanceautoparts.com/p/dorman-conduct-tite-electrical-tester-in-line-spark-plug-checker-86579/22144233-p?c3ch=PLA&c3nid=22144233-P&adtype=&product_channel=Online&store_code=&msclkid=fce703ef64e41f7d62ae616a581f9131&utm_source=bing&utm_medium=cpc&utm_campaign=b_shopping_all_dorman_gen_gen_gen_evergreen_eng_aap_us_all&utm_term=4580290575192439&utm_content=Bing_All_Dorman%20-%20Innovation_Dorman%20-%20Front%20Room&gclid=fce703ef64e41f7d62ae616a581f9131&gclsrc=3p.ds

Also check the fuel pressure at the rail when cranking with a test gauge.

If this is a single fuel line system without a regulator and return line, the pump voltage is varied by a module to prevent pumping too much fuel. Make sure the grounding and connections to that are clean and tight.

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Also, plug wires can break down and short to the cylinder head on this type. You can tell by pulling them out of the head to check the outside of the boots for traces of arcing. Don't fit cheap plug wires on the shelf at the local parts store.

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@John B, I plan to also install a battery master switch (and might as well go with a track-suitable switch).  Sounds like you're happy with yours.  Any recommendations?

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I now have the multimeter reads.  Unless a time is given, these were done immediately, one after the other.  Note that before hooking up the trickle charger, the battery gauge was never noticeably past 12V when cold.  Now, with the trickle charger, the gauge is well above 13.  Seems the gauge is measuring pretty true.  Definitely have drain.  Will be installing kill switch and looking for bad grounds.  I have not yet tried @MV8's latest suggestions.  Have an appointment for service on Tue next week (a shop with Lotus and Seven experience).  

 

On trickle charger (2 days since last start), cold, key off:  13.4

On trickle charger, cold, key on:  13.4

Off trickle charger, cold, key off:  13.3

Off trickle charger, cold, key on:  12.6

* Started the car (off charger) and it started fine and idled smoothly (no revving)

After idling 5 min:  13.7

* Drove 30 min (~15 min on interstate at ~70mph, ~15 min in stop and go traffic)

After drive, idling:  14.0

After drive, off charger, just turned engine off, key on:  13.0

After drive, off charger for 30 min, key off:  12.6

After drive, off charger for 30 min, key on:  12.5

* Car started (off charger) then immediately died (no revving)

After drive, on charger for 30 min, key off:  14.1

After drive, on charger for 30 min, key on: 13.9

* Car started fine (off charger) and idled smoothly (no revving)

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Based on all that I feel like your alternator works, but you've got an idle issue.  It seems like a little throttle on startup leads to a happy car experience?

 

You may or may not have an issue with some dark load on the battery.  Are you going to let it sit overnight, then more tests?

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Do a leak down test.

test voltage after sitting two days off charger.

Don't test it in between days, you'll want to mess with it.

Let it draw down.

I have a suspicion you probably fixed the issue with some connections you tightened. 

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  • 2 weeks later...

In line with @MV8 sounds like a battery drain with the system off. If you have a meter with Amps on it, take off one of the battery leads and put the meter in series with the lead and battery terminal, that'll show right away if there's some current.

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Thanks, @sf4018.  I'm sure you guys are right.  I'm currently traveling, and the car is having a battery master switch installed and a poke-around to try to find the source of the drain (and work to resolve the backfiring). 

 

@Austin David, I'm looking forward to making that video/audio for you!  When I've had passengers in the car, the sound of the supercharger seems to add to that white-knuckle, scream-like-a-little-girl reaction.  :classic_biggrin:   

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  • 1 month later...

Finally closing the loop on this.  Starting problem persisted even after installing the kill switch, but only when trying to restart after driving the car <5 miles.  Could still jump it, and alternator still recharged it up to ~14V while driving.  Finally got rid of that Napa lawn and garden battery (on the car when I bought it) and installed an Odyssey PC625.  Even though it has lower CCA (220 vs. 300), reads on a multimeter well below that from the Napa (right at 12V vs. above 13V right off the CTEK 5.0) and gage never gets much past 12V while driving, the PC625 battery is doing just fine.  Should have just done that in the first place.

 

@Austin David, I attempted to make a driving video that included the sound of the supercharger spinning up, but the audio is crap.  Mostly just wind and various tools clanking around in the boot.  After finding the very nice audio tutorial from @Croc (thanks for that!), I'm going to need to get a decent powered external mic under the bonnet if I want to get good engine audio.  Meanwhile, may just do one in neutral.

 

Thanks again to everyone for the pointers.  Turned out to be ridiculously simple after all my over-thinking.  Use the right battery, despite the specs on the label.

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  • 3 weeks later...

@Austin David, Finally here is a video with audio of the SC that you asked for.  Since I mentioned @Croc's audio tutorial above, I feel obliged to point out that this does not at all live up to his great recommendations.  That's because I went full on cheapskate and bought a $12 Amazon prime day non-powered mic (and that included an open frame mount for the gopro).  So, at best, this is 12 bucks worth of audio quality.  But, it'll do.

https://drive.google.com/file/d/1h6Nzmt2cdcAtADScxn3Vun5fdD7IIN0p/view?usp=sharing

 

Notice that engine hiss at the beginning of the video?  This seems to have gotten substantially more noticeable in the last couple weeks.  Vacuum leak?  That would be consistent with the backfires.  I guess that's the next issue to sort.

 

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Reportedly 200 rwhp.  Not sure if it's hitting that currently, but feels pretty close to me.  I'm hoping to get it dyno tuned soon and we'll know for sure.  If you didn't notice in the video, that was pulling all 260 pounds of me up hill.   

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