Weird electric problems, car won't start

[Pug30614]

I have a 1999 phase 3 1.4 306 with the sagem ECU.

To cut a long story short a friend borrowed the car and filled it with diesel, it still started fine and everything was okay apart from it was smoking bad and misfiring.

I replaced the fuel with fresh petrol, replaced a bad injector and all the spark plugs. It was left sat for a while before I had done any of that but when I had done it and went to start it I only had 1 light on the dash which was the battery light.

The pump primes and kicks in but I get no spark, I've used other parts from a doner car that were known good parts, these included coil pack, crank sensor and the exact same ECU with the transponder chip and ring. None of this cured the problem.

I've checked all the earths and they are good, I've checked all the ignition wires and they seem fine. I'm also not getting any communication from the OBD, I'm using a snap on machine.

I've also checked the inertia switch and all the fuses. They are all good.

Anyone shed any light on this???

[andywhy]

Oops, didn't read properly, was going to suggest checking fuses.

[Toms306]

I didn't think you could fit a diesel pump in a petrol filler, they should have a smaller neck?

You need the black box under the dash if you've changed the ECU and key though, the ring isn't coded, immobiliser will be stuck on without that.

[Pug30614]

Even if I needed the black box the lights on the dash should still come back on because the immobiliser has nothing to do with the dash lights as far as I'm aware

[Toms306]

Ah I see, I read that wrong, assumed you meant the only light that remained on was battery light, not the only one at all lol! But still, it won't start without that unless the ECU has been unlocked.

Light issue sounds like a wiring fault. Either the round plugs on the lower nearside front, by the radiator. Remove them to check for corrosion or damage. OR could be the loom from those plugs that runs under the front of the chassis. Check the main earth cable that joins the battery to the gearbox, some of them are just hanging on by one or two threads these days. Might also be worth checking the main large plug that is underneath the wiper motor, I've never seen one of them suffer water ingress though.

[Pug30614]

My headlights still work if that's what you want me to check for at the plug near the radiator? I just meant all of the lights on the dash don't work apart from the battery light, my mileage doesn't even show up unless I turn my side lights on.

And for the earths, I've ran a jump lead from the negative terminal to the ground on the gearbox and even connected it to the little earth point under the steering column inside the car. But I have a probe tester and I seem to be getting an earth there, I've even checked the earth point on the drivers side seat belt pre tensioner. According to autodata that earth point has something to do with the engine management along with the gearbox earth strap

[Toms306]

The ECU wires are on the chassis plug by the radiator which is why it needs checking. Could explain why you're not getting an ECU/OBD connection.

Seems like you've covered earth tests!

[Pug30614]

Okay I'm back at the garage tomorrow so I'll check the plug for any broken wires or corrosion and let you know what I fine. Is it a round plug?

[Toms306]

Yeah, two round plugs, they'll be obvious if you follow the engine loom, they have twist lock connectors on them, may have to tap round with a flat blade and hammer to remove them.

[Pug30614]

I've been pretty busy these few days and I've just had a quick look but as I was doing so I saw a bit of corrosion on the 3 live cables that connect to the positive on the battery. Could that be a cause of the problems? I'm gonna strip them back a little more to see how bad they are.

[Pug30614]

Ohh and before I went to start the car I removed my head unit so I could put it in my car. Could that have anything to do with it? I can't see it but a guy I know said he the radio wires are linked in with the OBD somewhere

[Toms306]

Hmm, I haven't seen problems with the main positives before but depends how bad it is I guess!

Stereo removal doesn't make a difference on these.

[Pug30614]

Well the battery is on it way out and I have an aftermarket alarm fitted so when I lock it the alarm goes off if there's not much juice in the battery so I've had to unplug the positive terminal off the battery quite a lot of times so I'm thinking with the constant moving and bending of the cables that could of caused them to break