348 missfire

Well i have been finally hit with the 348 gremlins. Last few weeks when stopping for lights the car has misfired for a few seconds. Happened 2-3 times. Thought it may have been water in the system as i have been caught in the rain quite a few times lately. Today at around 2000 RPM seemed to suddenly miss badly. Almost as if it was running on 4 cylinders only. When i drove below 200 rpm it was alright to limp home.
Got home and decided to reset ECU, so turned off the switch waited for 2 minutes and commenced the re-learning run through process. Everything was normal until i went to drive away. Misfire returned. While the engine was running, JUST, moved the ignition leads on the right hand coil pack and returned to normal again. Ran well for a minute and then misfire returned. Now it will not even idle at all.
O'K a few weeks ago i cleaned the crank sensors and discovered that the connecting plug to 1 had broken up. Reconnected and seem to run fine.
I plan to replace both firstly. My other thought was it had the symptoms of a fuel starvation issue. Have 2 spare fuel filters so will replace those tomorrow.
Any other ideas guys? HELP

 

Time is not kind to the electrical bits in old cars. You may have to do a complete electrical service to find the bad connection(s). Be sure to check to make sure your grounds (earth) are good, a bad connection at a ground can cause this kind of trouble also.

A clogged fuel filter would not cause this kind of mis-fire, but fresh filters and an injector service (cleaned and balanced) is always a good idea on an older car.

Scott

 

Thanks Scot, i am thinking it is an electrical fault myself. After the first time i wriggled the leads and that fixed the fault, it would not do it for a second time when the fault reoccurred. I have done the same with both coil packs. Fault is now constant.

 

Based on your description, my guess would be that the problem is at the crank sensors or the wiring at the connectors to them.

 

+1!

I reckon its in the connectors personally.

 

Candellara on Club Scud had a similar problem, crank sensors too.

 

Thanks guys i think what i will do is replace both crank sensors and coil packs. While i am at it may as well do what Marco has done and replace ignition lead cables.

 

Inspect/replace the crank sensors first mate and go from there.

You dont want to replace the coil packs just for the hell of it.

 

+1

 

Problem found, crank sensor plug fallen apart and contacts touching.
Thanks to all.

 

There ya go, ya cheeky chop!

 

Look up my post on the replacement of the Bosch units... Will run you £80 for both (and do both now that you are there). If you need help, I have access to a lift etc.

Back in the UK now...

Marco