Mitsi V6 3.0 6G72 Wont Start ??

[suzolla]

Hi, need some help

Got a Mitsi J Top with the above engine and it wont start which has me baffled.
Seems to have fuel but no spark, took the lead off the coil and checked it against the engine.
This is third time it has happened, last two times after lots of cranking and fiddling around it fired up and then would run and start again no problem. Was running fine a week ago.
One possible common factor is prior to it not stating, the battery had been disconnected for over a week.

Is there something that needs to be done to get it going after the battery being disconnected, or any other thoughts on what might be the problem, not very familiar with electronic and efi system.

Very frustrating when it was going so well before

Cheers
Tim

[Crash bandicoot]

Only thing off the top of my head if its a self learning ecu is the rom might be damaged in the ecu and forgets some of its predefined maping

[Crash bandicoot]

If it fires again and you need to take the battery out try not to leave it out too long.

[nicinnz]

ECU would be my bet try another ECU or send your one away to get repaired. Its a Common fault loosing the spark.

[Team Tonka]

ECU on these is pretty good and when they do fail its usually the fuel pump control that craps out. Look for poor connections, damaged wiring and connectors with the tang broken that can come loose. Transistor unit near coil can fail and so can pick up in distributor. I have a shed full of parts for this motor. You can have any of the above for $10 plus post when you track down the fault. If you want to substitute parts to find the problem I'd be happy to let you have parts on a pay or return basis if that helps. Cheers Andy.

[suzolla]

Hi Andy,

Thank you for the offer, much appreciated, just need to track down the fault.

Bazaar thing is the only thing done between running and then not starting is disconnecting the battery.

Had a search on fault codes, found a post on another forum listing the codes but couldn't find the plug to connect the test light to, the post seemed to indicate that it is in the drivers foot well but couldn't find it.

Are there any one line manuals.

Cheers
Tim

[Team Tonka]

Hi Tim, if you PM me your email I'll scan in a few manual pages and flick them to you. Cheers Andy.

[kaupoi]

Ecu mate, i had two pajeros both with 6g72 in them, one wouldn't start so swapped the ecu over and away she went first pop.

[suzolla]

Thanks for the replies, looks like I need to find an ECU to try, anyone know of one to either try local to Hamilton or one to buy.

Question, will any 6G72 manual ECU do, or is it vehicle model specific.

Cheers
Tim

[kaupoi]

One of my pajeros was manual and the other auto, worked fine.

[suzolla]

Did you put the Auto one into the Manual or the Man into the Auto.
Cheers
Tim

[churchill]

Check the MPI relay next to the ECU.

[kaupoi]

I put the auto one into the manual.

[NJV6]

I think I have one or two in my box of ECU's, you can have it for the price of postage if you want, downside is, its near Gore... Both from 5 Speeds.

Glen

[suzolla]

Hi Glen,
Sounds Great, will send you a PM
Thanks very much
Cheers
Tim

[suzolla]

Hi Glen,

ECU's arrived, tried them both tonight but still no go, seems to be no spark at the coil.
Any more suggestions, checks to try. Anybody ??
Cheers
Tim

[Crash bandicoot]

Open up the coil loom and give it its own power feed if still nothing it will be the trigger from the CAS

[Crash bandicoot]

If it,s hall effect sensor it will have to sets of grooves one for injector pulse. One for ignition pulse

[suzolla]

Thanks for that.
Found this http://easyautodiagnostics.com/mitsubishi/3.0L/ignition-system-tests-1
will give it a go tonight

Cheers
Tim

[suzolla]

Well finally got it sorted fingers crossed, after lots of fault finding, the on line fault checking was really helpful and most useful was the wiring diagram sent by Andy, thanks very much for that.

Turns out ECU and all the sensors were okay, problem was there were two broken wires about 250mm from the ecu in the loom, they are meant to send an earth signal to the control unit relay so there was no power getting to the crank position sensor, really lucky it ran when it did on the last trip out.

Thanks for all the help and suggestions.

Cheers
Tim

[Team Tonka]

Pleased you sorted it. Good work finding the fault were it was. If you have not already done it remove the speaker and move the ecu up out of harms way. The wiring is long enough.

[suzolla]

Thanks for that Andy, previous owner moved it up under dash.
Cheers
Tim