Non Runner 4.5 petrol, help?

Hi Guys,
Joined up and had a good read, full of info and really pleased for the information.
Just bought a 1995 80 series 4.5 6 cylinder petrol injection beast. She don't run. This could be a simple problem that someone else has had experience with so thought would ask the question before i start jumping into diagnosis.
Had a flat battery and the previous owner accidentally connected the jump pack the wrong way around, positive to neg and neg to pos, then turned the key and tried to start it. Not sure what happened next as its a sketchy explanation!! needless to say it didn't start and with a new battery in place, correctly connected!, fully charged it turns over but won't run.
So, anyone had or heard of a similar thing happen??
Thanks for any replies / advice

Hi, I've not had that sort of experience but if you've just bought it as a project, that explanation doesn't stack up IMHO. You would need to be extremely stupid to put a jump pack on the wrong way AND leave it there as sparking or explosion even from a pretty dead battery would show that you'd done something very wrong!!

Anyway, you have likely got some serious problems there, anything from blown fuses to a fried ECU as its a petrol.

Have you checked all the fuses? Not sure on the petrol but on the diesel there are some under the bonnet as well as in the cab.
Have you got sparks?
Have you got fuel? Does it smell of unburnt fuel from the exhaust?

If fuses are all intact and correctly inserted, and you have no fuel or sparks, it might be worth checking if the ECU has power (not sure which pin(s) that is but someone here may know). If all seems fine there, my money would be on a fried ECU. Not sure if the ECUs are coded with keys or other parts, again someone here may know. Sometimes just changing the ECU is not enough.

I have a Smart car I bought that threw up a misfire. That ended up being a software fault probably from a bad jump start and cost far more than the car is worth to fix.

I did have good help and advice from the ECU Doctor who will test the ECU for a fee but you've a few steps before trying that.

Good luck

Just as an update, car running
Without dissing all tyre fitters out there it was a tyre fitter who connected the jump pack the wrong way round and tried to start!
Thanks for the reply Starcruiser but the above description was the correct one so not sure what didn't stack up in your mind? bought / swapped the car as a non runner. The fact he connected the jump battery the wrong way around may or may not have caused the reason for not starting but it was the previous owner who said it didn't start after that was tried......

Anyway, all fuses good, turns over but no spark or injection opening. After some time spent diagnosing and a used ECU tried, it turns out there are 2 power wires running to a small black connector block by the battery, one of the two wires had fried itself inside the sheathing so you couldn't see it, replaced the wire, got spark and fuel injectors opening but no start. Turns out to be a faulty fuel pump relay. Stripped and cleaned contacts and she runs like a sewing machine

One for the memory banks if anyone else encounters something similar

Now the basics can start like spending loads money on her to get ready for some bush bashing......

No offence meant Andy, my post was relating to leaving something in place that was or should have obviously not been right. Difficult to tell as I wasn't there but I was referring to the sort of stories that sometimes accompany vehicle sales. (Thinks of his own experiences here).

The fried piece of cable is (or was) a fusible link (just another type of fuse) and should be replaced with exactly the same part as it is designed to do exactly what it did and saves the wiring catching fire in the event of an accident (or a tyre fitter connecting a jump pack the wrong way round)!

Anyway…what a result!! And thanks for posting the solution. Well done for sorting it, you must be well pleased.

Yes very pleased thanks!! I got the impression the chap i got it off was a little annoyed it was fixed for around $200 and a load of time, but it did teach me a lot about the Landcruiser which i am pleased about.
Sorry Starcruiser didn't mean it to sound like i was offended, just a little puzzled by what you had written. Prob the fact i had not explained it clearly.

Its a pretty standard car just has a 2 inch spring lift with shocks (two rears are leaking). Currently doing a list of things to do before i venture onto the beach