Technical Advice: 1.6 missfire problems?

[Jonsey89]

Hi, i am having some trouble getting my 1.6 brava to run smoothly.

It has a really bad missfire...seemingly only on cylinder 1 and 4.

I have fitted new plugs and leads. Fitted a new coilpack and also tried a spare. Always exactly the same?

Injector light is on and there is a bad blow in the downpipe but does anyone have any other suggestions as to what to try....

Will check compression soon as a can get a tester.

Removed the plugs today and 2 and 3 are quite sooted yet 1 and 4 as they were put in. New.

I believe fuel is getting through to all cylinders as the plugs do smell of petrl when removed.

Any advice greatly appreciated.

Thanks

 

[Corvinus]

First you could try an ECU reset. Make sure you have the radio code first. Remove the negative lead from the battery and leave it for at least 1 hour. After 1 hour minimum, start the car but don't rev it, don't turn anithing on. Leave it for minimum 5 min to relearn the sensors and motors positions, then turn it off (don't worry if the rev gauge goes wild or the other gauges it's normal until it learns all it's presets). After this is done the ECU will learn in several miles the way you like to drive, and adjusts itself. If this doesnt work try to get it to a tester. Hope it helps.

 

[Adrian Bravo]

Hi Jonsey
Spark Plug 1 and 4 use the same winding on the coil pack, because of this I would look at the coil pack first and check those plugs HT leads.

Fully unplug the coil pack and test the resistance's as shown here.
Or just try another pack. Check the coil pack multiplug for corosion, it could be the loom's wire that goes to between ECU pin 37 and the coil winding but unlikely.

 

[Jonsey89]

As said, put brand new plugs and leads on all cylinders also tried a spare coil pack that came with the car then bought a brand new one. Always the same.

Due to it being 1 and 4 thats what made me think coil pack or connection problem along the way.

Will check the connector for any corrosion and try and follow the wire back to the ecu to check for damage.

Might try the ECU reset but the car has no TAX or MOT so cannot be driven (at all as it is).

Any other suggestions greatly appreciated.

Thanks guys.

 

[dave0011]

im having same problem no luck yet ive changed a load of stuff see my post going to try and test the injectors today if you get yours sorted will you let me know and i will do the same for you it seems we both have the same problem
dave:idea:

 

[BogdanXB]

Hi there. Could anyone please give me some constructive suggestions. I have a brava 1.6 2001, the check engine light came up and it started shaking, running on 3 cylinders like. I changed the sparks but no difference, it seems to get worse every time I start the engine. I took it to the service for a diagnostic and the error codes given were PO135-O2 Sensor Heater Circuit Bank 1 Sensor 1, PO202-Cylinder 2 Injector Circuit and PO300-Random Cylinder Misfire. Any ideas of what could it be? As the misfire changes from one cylinder to another, could it still be an injector at fault? or the ignition coil.. Thanks a lot.