with a new house and job on the way, the last thing i needed was the car to play up! any advice gratefully received - a few days ago the fuel injection warning light lit up on the motorway, and revs dropped severely. pulled off at the next junction and mr green flag came to inspect. he reckoned it was the plugs and leads, which i have now changed with no result. funny thing is, sometimes the car is fine and i can drive 30-40 miles and you wouldnt suspect anything of being wrong, then all of a sudden the light comes on and its 30mph all the way home. sometimes it starts in this condition, then down the road the warning light goes off and full power returns! took it to a local garage today and he couldnt fix it but said something about the engine going into power safety mode & on three cylinders?????

Help

What model, year and cc?
Tony.

you really should tell us what car you're talking about.


intermittent faults like this are often sensor related. a diagnostics check at fiat would be the best bet (£30).

although it also smells like the early signs of coil failure.

Doh! It's a brava 1.6 100sx, w reg, 2000. Coil failure? Wouldn't that have been spotted by the mechanic? And would that allow it to run normally for 90% of the time? It's odd that it only loses power/has warning light randomly for about 20 minutes, and can then be running fine??

Thanks for your input...

Jimmer

yeah i know what you mean a coil failure is usually permanent. but if its just beginning to fail it may have periods where both coils are giving an output and other times when only one is working. thats often how they start to fail.

but thats not important now that i know you have a 1.6. you have injector failure, it always is on the 1.6. even fiat fail to spot injector failure, and while they are also usually permanent faults, i've seen injector failure to be intermittent at first (my first bravo was like that for weeks according to previous owner, sometimes fine sometimes rough as a bugger, it was fine for periods when i first bought it)

there are millions of threads about diagnosing and repairing 1.6 injector failure (many of them by me) its so common i could cry.

basically a multimeter should be used to measure the resistance of the injectors, a good one will be at least 14ohms, any less and you should replace it with one from a scrpayard (£5 each) that is at least 14ohms.

to test the resistance disconnect the injector wiring harness at the right hand side of the fuel rail. on the injector wiring harness connector there are 5 pins, the centre is earth and the other 4 are each for an injector. measure the resistance across the pins (using the centre pin as negative on each test) to identify if one or more has failed.

replacement is very easy, you just loosen the upper inlet manifold enough to get the fuel rail off. then swap injectors over and refit. easy 1 hour job, and cheap to do as well. hooray

thanks very much for your advice, i will get onto it right away! otherwise the car has been great, apart from the funny position of the accelerator, which seems inordinately high and gives me cramp in my foot!

if you haven't got a sunroof leak then you've done well

i finally stopped my sunroof leak, it took a lot of black putty, a lot of investigation, much patience, several attempts, some bleach and mould remover, oh and a few kettles full of water. hope it doesnt leak ever again. if it does i'm welding it up once and for all.