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Premium Member
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Discussion Starter #1
Hoping the community can help fast track my diagnosis here.

Long story short I just finished a 1.5y upgrade on my Exige (personal life/family slowed me way down). Tried starting it yesterday and all I get is cranking with the dash blinking (flickering off/on, all the lights).

  • 1/2 tank fuel
  • Immobilizer bypassed
  • No codes on ODB2
  • Fresh tune from BOE on ECU
  • Fuel pumps (in tank and BOE surge) are working and supply fuel (validated on FPR gauge)
  • Brand new injectors (REV400 kit)[/INDENT]

    • Verified 12.6 ohms across both injector terminals
    • 12V on + terminal using engine ground
    • 2.6V on Ground terminal -- Shouldn't this be 0 with the key on?:scratchhead:

Next, I'm going to check the spark plug harness, only because I'm out of ideas. I want to drive my Lotus so bad right now...:mad:


Does anyone have advise why it won't start? All I get is cranking doesn't even sound like it trying to fire.
 

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733 Posts
are you confident that your ground to the engine block has good continuity? i also think the battery ground terminal should remain at 0V relative to the block. or did you mean that you checked the injector pin voltage? in that case, it might make sense that the voltage is not zero.. i think that the ecu runs the injectors by switching on the ground side.


a bad battery ground is consistent with some flickering lights and possibly the ecu losing power at times during cranking.
 

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Are you saying it's not started since your new BOE tune was installed??
 

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Discussion Starter #5
Are you saying it's not started since your new BOE tune was installed??
Yes, ECU was freshly tuned by BOE in April/May and sat in the box until recently when I installed it.



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A1 Automotive & Smog
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910 Posts
Check the fuel cut-out switch. It's in between the expansion tank and windshield washer bottle. Press down fully.
 

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Yes, ECU was freshly tuned by BOE in April/May and sat in the box until recently when I installed it.
Perhaps ck with BOE.

Check the fuel cut-out switch. It's in between the expansion tank and windshield washer bottle. Press down fully.
He said fuel pumps are running.
 

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Premium Member
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502 Posts
Discussion Starter #8
Chassis, trans, ecu ground, and spark plug ground continuity test all verified. Did I forget any?
Camshaft sensor: The resistance is within spec @ 1,125 (spec = 835 - 1,400 ohms)
Spark plug: harness has 12.5V with the ignition on (measuring to the two outer posts ground and +)

Injectors: I do not have continuity from the battery negative post to the negative wire on the injectors with the ignition off. I'm thinking I should right? Or is that switched by the ECU?
Injectors have 12.5V measuring positive lead and engine ground.
I get no voltage measuring across the + and - terminals on the injectors. Based upon my continuity test I'm thinking the ECU is controlling that and grounds them out to fire/open.
I measure 12.5V on both + and - terminals on the injectors using the engine ground. That's weird right?

I'm going to harbor freight to get a NOID kit tomorrow to test the injector harness.
Still no codes.
 

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502 Posts
Discussion Starter #9
Update on this.

1. Tested with NOID kit, injectors not firing.
2. Got pissed off.
3. Pulled my F150 up and attached jumper cables to the Exige. Damn thing fired right up.

Moral of the story, stop over thinking it. The odd thing is my battery tested just fine during cranking with the multimeter.

Installed a brand new Shorai LFX36L3-BS12 (which is really awesome and weights 4lbs) today and it starts right up.
 

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Acme Super Moderator ** The Enforcer **
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7,594 Posts
Installed a brand new Shorai LFX36L3-BS12 (which is really awesome and weights 4lbs) today and it starts right up.
4.55 lbs, but still awfully light. I've had mine for 4+ years now. Did you get the charger too?

Good to hear it was something simple.

San
 

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07 Exige S
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1,572 Posts
Keep that little sucker on a battery tender. I have one of those older smaller batteries offered by Sector111. It has been fine for over 5 years. I keep that little guy on a battery tender like it's a religion. No problems.
 

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Discussion Starter #13
I had an Odyssey PC680, which has to be 4-5 years old, always on a float charger.

Bought the Shorai charger to get the BMS functions for the new battery.

My next problem is it will not idle. Runs fine with my foot on the gas. Thinking it's the throttle body and something with idle air control.

Starts, revs to about 3k, dips to 800ish, spikes to 2kish, drops to 500, sputters, dies.



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Sounds like how my car was running when I accidentally unplugged the MAF sensor while doing some work in that area. Worth a look.
 
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