I'm a noob when it comes to cars so maybe you guys can help? I was driving home today and for no apparent reason there was a loud sharp bang from the engine and the car just died on me. Scarey as hell coz a minute later i would of been hurlting down the motorway at 90ks an hour with no power steering and no brakes. Luckily enough i was only doing about 20 in a carpark.

RACQ dude rocks up and has a poke about, engine starts fine and runs, about the only thing he can say is that there was a strong smell of gas (aftermarket dualfuel, running on lpg at the time) and a ticking sound that suggested that something (leads?) might of been arcing. He suggests i get it towed to a workshop but instead i opted to take my chances running on petrol to get it home.

So here i am, anyone got any ideas as to the cause? I'm going to try and get her looked at tomorrow so it'd be good to be armed with some suggestions!

A couple of other (possibly related) items: i started the car from cold last week on gas and the engine turned before there was a bloody great bang...could this be the same thing? Is this a misfire and would it cause my engine to stop? I'd not know what one sounds like - what causes it? Also on occasion the engine will seem to momentarily lack power when putting my foot down...and only when running on petrol. She also idles roughly on petrol.

Any help will be greatly appreciated!

Dan

hey try replacing leads, just did a mates el (non gas) and it idles good now and has no more miss fires, but other then that im not sure.


brett

Common cause for backfire are leads and then plugs. Possible causes after that may be coil(s) or dissy. After a backfire check the MAP sensor vacuum line is still connected and while you are there check the two hoses to the rocker cover have not popped off.

So it's a backfire then not a misfire? What's the difference? Where abouts is the map sensor vacuum line so i can take a squiz? Will check the rockercover hoses too, though i think they were all ok.

back fire is a the explosion of fuel/air OUTSIDE of the combustion chamber in the intake tract

while misfire is when the spark plug/s do not ignite the fuel/air mixture correctly to promote combustion

Ah ok...so which one is worse....and which have i got?

u have a BACKFIRE

just as bad as each other as both can cause damage to engine

change ya plugs and leads

If your already running good leads, then just replace the plugs. I used to listen out for this - the smallest sign of backfire just meant time to change the plugs.

When your checking - make sure that all of the rubber joins in the Pipe work from the airbox to the manifold are still done up. They can blow off with a backfire.

A lot of people leave the airbox clips off so that if there is a backfire then the pressure can relieve easily. Put an ocky strap on if you need to to hold them together. Saves blowing $lots on new airboxen.

Cheers

Nigel

Allrighty then, backfire it is. I'll take the car to the mechanics in the next few days and get some new plugs and leads...or is this an easy enough job to do myself? And just to be certain, would a backfire stall the engine then?

do it yourself its is the most simple procedure you can do in the engine bay

Change your plugs and leads, but then get the gas tuned, it could be running too lean which will also cause a backfire.

hmm i got the mixtures adjusted under a month ago...

In that case aslong as it was done right i'd go plugs, leads and check for vacuum leaks as others have said.

Distributor for sure.

I bet your wishing you spent the extra bob on a good car instead of the ex cab?

The pics look like an EF... Therefore no distributor.. Do not open mouth unless you actually know what you are talking about, again!

And chances are it is as everyone as had. Old leads and plugs will cause a backfire, making a very nice bang out the intake (in most cases blowing the intake apart if its an EF one). They would be the first place to start.