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Discussion Starter #1 (Edited)
At the end of last season, my Elise was running fine. In my questionable wisdom, I decided to do some track mods over the winter. The list is long and I won't bore you with the details unless someone tells me they're pertinent to the problem at hand.

Today I finally got everything reassembled and unsuccessfully tried to start up the car. When I hit the start button, the starter made a "clunk, clunk, clunk" but the engine did not crank. When I have had a low battery I have experienced the "tick, tick, tick" sound. This was much slower than that sound and much more forceful. It actually felt like the starter was engaging the ring gear because each clunk would shake the car a bit just like when starting the engine normally. When this was happening, the instrument display would flicker on and off.

I have had the battery on a Battery Minder and it's fully charged. I even tried jumping with a spare fully charged battery with no change in symptoms.

I have adequate fuel pressure per my BOE surge tank gauge. I haven't checked for spark yet primarily because the engine isn't even cranking.

Can anyone suggest what my problem might be?

thanks,
 

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At the end of last season, my Elise was running fine. In my questionable wisdom, I decided to do some track mods over the winter. The list is long and I won't bore you with the details unless someone tells me they're pertinent to the problem at hand.

Today I finally got everything reassembled and unsuccessfully tried to start up the car. When I hit the start button, the starter made a "clunk, clunk, clunk" but the engine did not crank. When I have had a low battery I have experienced the "tick, tick, tick" sound. This was much slower than that sound and much more forceful. It actually felt like the starter was engaging the ring gear because each clunk would shake the car a bit just like when starting the engine normally. When this was happening, the instrument display would flicker on and off.

I have had the battery on a Battery Minder and it's fully charged. I even tried jumping with a spare fully charged batter with no change in symptoms.

I have adequate fuel pressure. I haven't checked for spark yet primarily because the engine isn't even cranking.

Can anyone suggest what my problem might be?

thanks,
I think a list of mods would be useful. BTW, try rocking the car backwards and forwards in gear and see if anything changes.
Michael
 

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Agreed, put the car in 6th gear (which give you mechanical advantage), and push it forward and backwards a few feet. If the rear wheels will not turn, then something in the engine is definately locked up (not your starter). You are sure you didn't drop a nut or a socket which could get in somewhere and bind things up?
 

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Discussion Starter #5 (Edited)
I didn't intentionally remove any wires from the starter.

The only time I exposed the internals of the engine is when I replaced the fuel rail. I was careful not to let anything fall down the injector holes.

I rocked the car forward and back in 6th and 1st gear. I could see the belt moving a little as I did this. Behavior when trying to start was the same after rocking.

I came back to the car a while later and tried again and magically the engine cranked readily with no slowing. I checked for spark by removing each coil and plug one at a time and cranking the engine with the plug grounded. I didn't have spark on any of the four plugs. The plugs looked dry when I pulled them. My fuel pressure gauge indicates pressure in the rail.

Some of the more relevant modifications I've done are:

*removed security system and bypassed the immobilizer
*installed BOE Surge Tank
*removed many electrical items: heat/ac system, pusher fans, water recirculating pump, audio, headlights, turn signals, door locks, windows, evap emissions system.
*Installed Braile battery
*Installed Katana SC

Not all of these modifications were done during this recent round of work.

Tomorrow I plan to swap in a known good battery from one of my daily drivers just in case both my Braile and spare are dying.

thanks,
 

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Discussion Starter #6
I tried to start the car with a known good battery. The behavior was the same as it originally was: the clunk sound and no cranking.

I have checked the fuses under the access panel, the fuses under the dash, and the fuses in the engine compartment.

What should I be looking at next?

thanks,
 

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Discussion Starter #7 (Edited)
i found that i had not reconnected the crank position sensor so i connected it. tried to start the car again and it cranked and fired. it ran completely fine. i shut it down after a few minutes and restarted it easily.

i came back to the car the next day and it was back to the original problem: press the starter button and "clunk, clunk, clunk". the belt does move a bit with each clunk. the dash lights flicker with each clunk also.

does this sound like a bad starter? is there any way to troubleshoot the starter motor or starter motor relay? i can replace it fairly easily but i have two HPDE days this weekend and little time to replace the starter.

can i bypass the starter switch on the dash to rule that out?

i also tried jumpering the negative battery terminal to the rear subframe just to rule out a faulty ground connection with the negative wire off the battery.

thanks,
 

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Discussion Starter #8
bump.

any suggestions would be appreciated.

thanks,
 

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Next time it clunk clunk clunks, give the car a Jump Start. If the clunk clunk goes away (the car turns over and starts) you are looking at a bad battery or a bad connection. If the clunk clunks remain while jumped, then look at starter and starter connections. (possibly a dirty oxidized/corroded battery terminal too).
 

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Discussion Starter #10
the clunk clunk happens both with Braile battery and with a jump start.

i plan to remove my intake manifold and SC to examine the starter better and replace it if needed.

thanks,
 

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Discussion Starter #11 (Edited)
i replaced the starter --> same problem.
i connected the positive jumper cable to the positive terminal on the alternator to bypass the battery wire --> same problem

any way to tell if my ECM is unhappy?

does anyone have a pinout for the multifunction relay unit located near the ECM?

thanks,
 

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Discussion Starter #13 (Edited)
finally!! maybe.

it's a bad MFRU i think. i wired a separate switch to the starter control wire and as soon as i gave it +12v the engine turned over, started, and ran fine.

i removed the cover from the MFRU and none of the internal components were corroded or burned though those signs aren't guaranteed telltales of a malfunctioning relay. i have to go back and look for corrosion on the harness.

there's no way i'll get a replacement MFRU before Saturday so i'll need to wire a replacement for the starter relay. any idea of which color wires are what?

my short term workaround doesn't guarantee that it is actually the MFRU. does this sound at all like the ECM?

thanks,
 

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Brown (thick 3.0mm) and Black (little thinner 2.0mm) are the relay contact wires. Of course it could also be the relay coil that is the cause. There have been some instances of the wiring terminals getting wet and corroded, that's my bet. Pull the plug and carefully check both male and female sides.
Michael
 

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finally!! maybe.

it's a bad MFRU i think. i wired a separate switch to the starter control wire and as soon as i gave it +12v the engine turned over, started, and ran fine.

i removed the cover from the MFRU and none of the internal components were corroded or burned though those signs aren't guaranteed telltales of a malfunctioning relay. i have to go back and look for corrosion on the harness.

there's no way i'll get a replacement MFRU before Saturday so i'll need to wire a replacement for the starter relay. any idea of which color wires are what?

my short term workaround doesn't guarantee that it is actually the MFRU. does this sound at all like the ECM?

thanks,
I just wired up a direct line from the battery last weekend... (Fuse-> push-button-> starter). Waiting for the MFRU to show up.
 
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