NJ Motor Missing Badly

[lionelk]

I have a 1996 NJ Pajero 3.5 ltr. It started missing when cold, was taken to a garage where the heads were removed and serviced, a coil was found defective so three new coils were fitted, 6 new plugs, plug wires and injector was serviced. The original problem still exists, moreso when the engine is cold. Driving at 90 km/h not missing, reduced to 70 km/h touched the accelorator and the vehicle misses badly, and will continue to miss while held at that speed. The car was then taken to a Mitsubishi service centre and they were unable to find the problem.

Any suggestions on what I can do to fix this problem?

[Hawk-eye]

Could The Dealer Reproduce The Problem?

[RealThumbz]

ignition timing?

However in the world that engine decides when to fire the sparks, those symptoms sound exactly like what can happen when the ignition timing is quite a bit too far advanced. As soon as your 'idling' along at any speed where the engine isn't really working, you get that stuttering...?

[M Roadster]

Hi, had a Jag years ago that had the same symtoms, found it to be a faulty one way vacum valve. Check for a vacum leak, fingers crossed.

Mike

[6G74]

If there was a vacuum leak bad enough to cause this i would have thought the mechanics would pick this up rather easly with their scan tool.

Does sound ignition related - all thats left is ignition modual and crank angle sensor, i wouldnt think a crank angle sensor is likely.??

[paj862]

scan tools are not a replacement for good old fashioned diagnosis have a good look around the throttlebody for any hoses that are split/broken. other possibilities are faulty airflow meter, crank angle sensor or maybe even an injector blocked

[breadman]

I had a Range Rover many years ago that had the same problem, it turned out to be the brake booster, Air was getting past the diaphram as it was split and this was causing a vacuum problem.

[gjh1967]

check the fuel quality (water in fuel)

idle control solenoid

low water level in radiator also causes throttle body to overheat which plays up with idle.