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Misfiring on one cylinder
Posted: 13 Mar 2017 16:23
by breakwater
Recently purchased Patrol 1998 4.5 GRX,my second Patrol. Occasionally on starting or whilst running drops one cylinder. Three weeks with Nissan and no cure.
All new plugs,plug leads,rotor,distributor cap,distributor serviced, injectors cleaned by Bosch,new fuel pump, air filter clean. After a few ks or minutes it usually comes right.
All computer diagnosis stats as per Nissan spec.
Re: Misfiring on one cylinder
Posted: 13 Mar 2017 17:05
by hugejp
Sticky valve??
Re: Misfiring on one cylinder
Posted: 13 Mar 2017 17:46
by Tinus lotz
Give graham a call but sounds like maf or sticky valve to me....
Re: Misfiring on one cylinder
Posted: 13 Mar 2017 19:49
by Michael
Have they measured the compression?
Re: Misfiring on one cylinder
Posted: 13 Mar 2017 22:25
by Wilkie
That sounds like all of the above....and
on top of the inlet manifold towards the fire wall side there are two air valves from tappet cover ..clean them out and free of carbon built-up....and
see if your car has got a uni chip in ..that's how they start when they are about to give trouble

Re: Misfiring on one cylinder
Posted: 14 Mar 2017 05:46
by Michael
Ek is nou nie n petrol expert nie, maar as die intake manifold lek op een van die ports en hy suig lug daar kan hulle so maak?
I would do the following, when its cold and misfiring, pull the plug wires one by one untill you get to the cylinder that has the misfire. At least if you know which one has the misfire you can focus on that one area to find the problem.
Re: Misfiring on one cylinder
Posted: 15 Mar 2017 09:31
by hugejp
Has the mystery been solved??
Re: Misfiring on one cylinder
Posted: 15 Mar 2017 17:07
by breakwater
Guys
Thanks for all the tips. I will get round to all of them in time. I have started adding Valve eeze to all petrol fills and so far the problem seems to be absent but I suspect that will only be temporary. As you will all know getting to the plug leads 4,5 and 6 is not the easiest thing in the world especially for an oldie at the side of the road .
I have some reservations about the air control monitor valve and there is a company in Jburg called On line car parts who said they would supply me with one for a fraction of Nissan charges (R 12000) but I am in Richards Bay and not quite sure that what they would supply me with,probably Chinese would do the trick or even fit correctly.
Anybody any experience of these people ?
Many thanks once again
Pilot
Re: Misfiring on one cylinder
Posted: 31 Mar 2019 07:08
by BaasWiets
Morning has the problem been solved my 4.5 also started doing this after a couple of km it gets itself right.
Re: Misfiring on one cylinder
Posted: 01 Apr 2019 09:42
by ricster
It's a pity this thread ended a bit abruptly, hopefully someone can shed some light on the problem. Sadly I am a little more knowledgeable on diesels than petrols