Megasquirt not starting. shorted now coill side issue - help

[mattrosersv]

Car back together, but no spark

Stupidly when I pulled the box I did not disconnect the battery and shorted the starter terminal against the block.

Anyway I can see I have engine speed on Megasquirt but nothing on the tacho. This leads me to believe that my issue is with my Megasquirt not feeding the coils. Sound right?

I don't suppose there is a simple fuse anywhere? Can't see one.

Suppose I had better take my MS apart and look for burnt stuff

Any suggestions gratefully received.

Matt

[mattrosersv]

No burnt stuff inside megasquirt. Stumped at the mo.

[Sardonicus]

What coil packs you using if Ford then check you have a 12v + to the center pin of both coil pack 3 way connectors either with the ignition on or while cranking (depending how yours is wired) I reckon you have blown a fuse as when the ignition is switched off the MS is totally dead (no memory or constant 12 + necessary unlike the Lucas) I reckon your OK but next time ........... still better than the Nissan Nirvara I witnessed the other day that had just the same thing happen only it had a small fire starter + had earthed out through brake pipes while having a clutch changed under warranty (main dealer but not Nissan) totally stripping the coating off and causing a fire damaging the fuse box and arch liner the dealer denied knowledge of this till the owner told them it had just been MOTed and had an ABS repair by me and the damage was not present then the moral to my story is .... be more careful next time

Edited by Sardonicus on Sunday 13th July 21:35

[mattrosersv]

Thanks Sardonicus, I am a bit out of my depth here. I am using the early P38 Range Rover Coils.

Is the 12V feed just supplied direct from ign, or via MS? If from an ign live I can't see it being one of my standard fuse box fuses blown since ecerything else works.

Not sure what fuse I might have blown (can't see/remember) any new ones in my provided loom and MS - I may well be wrong on this tho.

Will have to takemy inlet manifold off for a looksee at the coils.

Cheers,

Matt

[Sardonicus]

Depends how your MS is wired but I prefer to have the ign coils fused independently of everything else i.e one 20A fuse feeds all your coils on your RR coil pack short loom red should have 12+ and checked how I said previously the coils are switched to ground by the MS but the 12+ supply does not come from the MS

Edited by Sardonicus on Sunday 13th July 21:51

[mattrosersv]

Thanks once again Sardonicus!!

I have 12v both to the injectors and coils without cranking.

Therefore I am guessing knackered coils/knackwred MS, or wiring between the two.

Stuck again .

I will also take the opportunity to big up Phil at Extra EFI who not for the first time has reponded to emails at all times to help me. Last time on Boxing day and now tonight.

[Sardonicus]

If the MS is showing RPM while cranking then the MS is powered and you have 12 v to the coils like you said yet no spark then (make sure that's during cranking too) if this is the case then you may have blown the spark drivers in the MS although not quite sure how , Phil can repair this though, sounds like a daft question because your using the RR coil packs but your not using EDIS for ign are you ?

[Sardonicus]

I presume you have checked your grounds for the MS as they may have been disturbed while you have been rocking/moving the engine about, I am assuming you have checked all your connections already however.

[mattrosersv]

So with ign off megasquirt coil connector disconnected at ECU and coils (testing just wiring) the loom all checks out EXCEPT for the red wire (two red wires jpining in the coil plug). While this shows 12v with ign on, also shows a connection to Earth...

Perhaps I have caught one of the reds between bell housing and and block.. Assume this is incorrect..

More investigation required tomorrow!

Thanks,

Matt

[mattrosersv]

It was a while ago that I setup the MS but pretty damn sure I did not configure as EDIS. It has been running for a year with no probs.

No other changes except for box and clutch change- oh and the dhead moment of forgetting to disconnect battery....

Woke up the middle of the night and realised I may have had ignition on. i was in the process of moving car whem it happened so may have had ign on to prevent stwering lock. Can't remember exactly.

Matt

Edited by mattrosersv on Monday 14th July 06:40

Just found my leaky earth. Fried relay. When i pulled it voltage dropped off slowly so assume there is a capacitor in there somewhere.

Replaced but Still no spark tho... Fried magasquirt....?

Edited by mattrosersv on Monday 14th July 08:52

[mattrosersv]

Tentatively I hink it is sorted.

Now have a spark. Replaced the relay again with a known working one off another car rather than one lying on a shelf in the corner of garage and I now have a sptark. Will get it back together this afternoon. Fingers crossed.

thanks to Sardonicus, Phil at Extra EFI and Shaun atMS2Tuning for their assistance!

Will confirm success/failure later

[mattrosersv]

Hurrah success... well almost. Seems to be making some unwanted noise. Edited to add noise gone. Suspect it was a bit of oil on the belt. Getting paranoid… MOT booked Wednesday.

Cheers,

Matt

Edited by mattrosersv on Monday 14th July 17:38

[mattrosersv]

Hurrah, MOT passed!!!

Once again thanks to all who helped me with this! In fact, thanks to all the knowledge shared on Pistonheads by some very clever knowledgeable people. It has made owning and maintaining my TVRs over the past 12 years hugely enjoyable and I have learnt a huge amount!.

The Chimaera is all polished up ready to be my wedding car on Friday!

Matt

[Alexdaredevils]

Nice one, got any pictures?