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Carbon Fiber
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1,637 Posts
Discussion Starter #1 (Edited)
Hey Guys,

Question is: What are the steps for your engine getting spark?

I understand the R7 fuse is for the injectors but it is fine....

Also I can here the fuel pump loud and clear also wet spark plugs, does immobilizer control coils too? ...

So what else can stop me from getting spark all of a sudden??

All spark plugs are brand new and did work fine for a week I had been driving. coils were working to because the engine did just run fine n still has not left the garage..

I have done some extensive googling on the site and am finding alot of un answered threads.

It all started About a week ago I replaced my intake cam. I started the car, it ran fine.

I was just letting it run and waiting to add some water and all of a sudden the engine started missing, stumbling and eventually stalling.

I broke the entire timing belt assembly down again, rechecked all my timing points and they are all dead on for sure 100%.

Then after I rebuilt it ran it again, sure enough it ran fine for a minute then again started to act up again, this time even worse..

I had tried to unplug the battery for 15 mins then test again. Running real bad... and this time I did manage to pull a code: P0601 Check Sum Error

Soooo I left the battery unplugged all night and now the thing would not start at all because the plugs are not getting power.

I have checked every fuse in the car twice, their all good.

Anybody got any ideas? Can I just get it reprogrammed? I can hear it running lol


I even unplugged the camshaft position sensor and then tried to start, I did get the p0335 stating it was missing so I doubt its that. Also Checked the compression, all 155+
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #3
K ordered, Ill try that before a 1200 ECU. Thanks for your input.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #4
Alright, Did get the sensor, swapped it out, still no spark. and yes the little ring on the crankshaft is there too...

Whats strange is last time I put the car together it did run just after a few mins started running rough. I just left for a while tried again and nothing, no spark ever again.. I am 99.9% sure it was not a timing issue or missing sensor or bad one, but hey why not tear it down one more time, im getting really good at that belt'

And at this point I have a new problem. I am not getting any spark on any coil from any plug ever..

If anyone could help me out id appreciate it

1. Does anyone know how to trouble shoot no spark?

2. is it possible to corrupt a tune on the ecu? I don't think the ecu is just straight fried casue eveything else works, but hey maybe it is...

3. Does the immobilizer cut spark should I consider bypassing it if all other functions seam fine?

4. do you know a fuse you can pull that you know wil cut spark? cause I need to load test that line...



I am done for today before I throw a wrench through the garage door.

Guess tomorrow I will take out the ecu, clean the connections and go from there.

Thanks to anyone willing to chime in'
 

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Registered
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488 Posts
I don't know enough to really help you like I want but, are you sure its a spark problem? Could it be fuel delivery?
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #6
Naa, I have the plug out grounded well, tried all 4 just for the heck of it..

Thanks though I'll take any ideA'

I smell fuel fooooor sure
 

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Gamera The Atomic Turtle
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3,349 Posts
above my pay grade or i would help. Where does the voltage driving the plug coils originate? Do you have the service manual? I'm guessing that you have already checked for pinched or broken wires leading to the coil/plugs. I hear they are easy to mess up.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #8
The coils are powered directly from the ecu. I know of the pinching issue others have had but that ain't it.
 

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Gamera The Atomic Turtle
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3,349 Posts
can you test the ecu out voltages? Is there a snap connector between the ecu and the coils that might be partially misconnected/partly connected?? Is there an obd code? You might want to see if Sir Lotus has an idea. He hangs out in "electrical". Actually, i'd pm him. He's the immobilizer expert. Or atleast one of them.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #10
Well I do have a wire diagram thanks to boe, I'll figure out which ones do what n test it at the cable end and ecu.

I don't think it'd be bad coils cause I tried em all.

I did get a few codes but they won't come back.

I did get p0601 once but never again, also the one about the crank position sensor but I was unplugging it and testing. Now that I know it's not the frank sensor I am sure that code won't b back.

If u pm'ed sir lotus cool, I see his awesomeness all over LT.

Guess at least I have a few things to get cracking on in the morning..
 

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Registered
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2,930 Posts
Did you test the correct coil wire for 12 v with a meter or test light ?
The power wire that feeds the coils can go bad in the harness. ( Green I think )
Check for voltage at the fuse and continue to the coils.

The coils are triggered by the ecu. via the ground.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #12 (Edited)
K I got 12v at the green wires by the coil, but I need to check all the wires now cause I got:

Green: 12v
Olive/black: 5v
Red/white:0v
Black:1.5v

Was able to do that without getting dirty, now I'm off to dinner.

Wonder why the 1.5 at ground.
 

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Registered
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2,930 Posts
K I got 12v at the green wires by the coil, but I need to check all the wires now cause I got:

Green: 12v
Olive/black: 5v
Red/white:0v
Black:1.5v

Was able to do that without getting dirty, now I'm off to dinner.

Wonder why the 1.5 at ground.
Don't worry about the other wires. Not relevant for what your working on.
Are you sure it's not firing? I didn't really read this whole thread.

You can attach an led between the green and black and looking for flash when you crank or pull one spark plug. Push spark plug into coil and ground spark plug to something. Crank and look for spark.

I have heard of ecu's not firing.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #14
Yes I grounded each plug and tested them, no spark.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #16
Ugh well if I end up getting a new ecu, it will need tuned so I wonder if I can just get one from toyota..
 

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Super Moderator
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2,844 Posts
Ugh well if I end up getting a new ecu, it will need tuned so I wonder if I can just get one from toyota..
Unfortunately the ECU is not a Toyota part. It is actually made in Italy and is unique to the Lotus application. Maybe you could find another local Lotus owner sympathetic to your cause that would borrow you his good ECU to see if it fixes your no spark issue before you purchase a new ECU. Other than that I can't offer any other ideas to help you. Good luck and I hope you can figure out what is wrong soon.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #18
Maybe vision function can test it or re-set it. Not sure.

I haven't asked yet but I'm hoping I can get someone to test my ecu

Still gonna play with the connections but it ain't looking good

1200 bucks for a ecu that I can't even tune.
 

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Gamera The Atomic Turtle
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3,349 Posts
so logically why/how could the ecu fail at this inopportune moment?(during a reaasembly of the motor.) A fluke? A cause? Is it possible to fry your ecu inadveretently while working on your car? I know from my old days on early pc's that checksum errors were bad. If it's even reporting that accurately. Just curious.
 

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Carbon Fiber
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1,637 Posts
Discussion Starter #20
Honestly I don't know, but I am a dreamer'

I know the battery was on the floor unhooked the whole time so I couldn't of shorted it this way
...

If I cannot find the issue, and send out my ecu, and that ends up being it'

I did get code: P0601 Check Sum Error once

I really don't know ll that much about the ecu but I do know it does fuel trims and does learn. Maybe just during initial boot up or the relearning process of the new cam just killed it.

Because the car ran like a champ the very first time I ran it after I changed the cam, then it got worse and worse then no spark.. that n and the fact that it has been making alot of noises lately Do :tadts:? makes ticking noises like a hard drive
 
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