Ford StreetKa - muiltypule missfire

Honest John Back Room » Technical matters
View Threaded
Wed 12 Nov 2014 19:20
Ford StreetKa - muiltypule missfire - bolddrick

engine starts fine but after a short time starts to missfire changed coil pack plugs leads and plugs erased fault code but aftter a run fault returns machine telling me muiltypule missfire can anyone help or come up with any ideas thanks

Reply | Report as offensive | Link
Wed 12 Nov 2014 23:06
Ford StreetKa - muiltypule missfire - elekie&a/c doctor

Did you use genuine Ford replacement parts or alternative products?

Reply | Report as offensive | Link
Wed 12 Nov 2014 23:17
Ford StreetKa - muiltypule missfire - Wackyracer

Have you checked to see what the long term fuel trim is? multiple missfires are often fuel related.

Reply | Report as offensive | Link
Thu 13 Nov 2014 00:51
Ford StreetKa - muiltypule missfire - bolddrick

not sure how to check fuel trim

Reply | Report as offensive | Link
Thu 13 Nov 2014 00:50
Ford StreetKa - muiltypule missfire - bolddrick

yes i used ford parts thats what i cant understand why its its doing it

Reply | Report as offensive | Link
Thu 13 Nov 2014 08:13
Ford StreetKa - muiltypule missfire - elekie&a/c doctor

All sorts of possibles.Air leak in induction/breather system,coolant temp sensor reading wrong?List is endless .Need the use of a good scanner with live data to help you solve this.

Reply | Report as offensive | Link
Thu 13 Nov 2014 08:25
Ford StreetKa - muiltypule missfire - Railroad.
P0300 - Random Multiple Misfire is generated when the ECM detects exactly that, a random multiple misfire, and nothing that can be pinned down specifically. Such misfires are detected via the O2 sensor. The ECM will detect varying patterns of information from the O2 sensor and will not be able to identify any single one cylinder that's misfiring, hence random and multiple.

The cause could be anything that could cause such a problem like a faulty ignition coil, worn or damaged spark plugs, intermittent loss of fuel pressure, sticking inlet or exhaust valves, worn valve springs or just about anything that could cause a random misfire.

To even begin to understand how the ECM works you have to think the way a computer works. They cannot think or apply common sense or reason. They do exactly what they're programmed to do and act on information received. Nothing more and nothing less.

Edited by Railroad. on 13/11/2014 at 08:28

Reply | Report as offensive | Link
Fri 14 Nov 2014 12:39
Ford StreetKa - muiltypule missfire - mfarrow

As AC doc says check a breather hose hasn't split or mis-aligned. I've plugged a hose onto a peg right next to the spigot once and couldn't figure out for ages why the thing wouldn't idle!

Other than that what hasn't been mentioned is try a pressure test.

Reply | Report as offensive | Link