Been having a bit of a problem with my Nissan of late and was hoping someone may be able to offer some suggestions. On a cold start up, my Nissan (Patrol 4.2 petrol/gas) tends to idle a bit rough, then for the first about 500m of driving it has small backfires (like little pops) and bugger all power. Then it magically finds its mojo and runs fine. If I flick it over to gas during this period, it runs fine as well so it only happens on petrol (but there's no LPG out here so that tank is getting a bit low). I changed the spark plugs and leads, fuel and air filters last week and still doing it. The fuel pump is only a couple of years old and I've run a couple of bottles of injector cleaner through to no avail. Any other ideas of where to look would be muchly appreciated  :-/

Have you got water in your petrol tank?
A couple of cups of metho in the tank will fix that.

Unlikely but can give it a go. Trying to hit all nails on the head before paying a mechanic to have a look. Have changed what fuel I'm putting in recently too. Was putting in 98 octane and now am back on normal unleaded just to see if it would make a difference after a few tanks

check the timing/dwell angle distributor could be a sparrow fart out with the injectors just a suggestion i have a 3.0 TDI patrol so i dont have those issues sorry

I'm  into turbo diesels.
Know buggerall anout engines in general.
Wish i  knew more about them.

Aart

oldbiker wrote on Sep 26^th, 2016 at 2:47pm:

check the timing/dwell angle distributor could be a sparrow fart out with the injectors just a suggestion i have a 3.0 TDI patrol so i dont have those issues sorry

Will have a tinker with that this week, see if it helps. Some days its not too bad and then others its shocking. Have pretty much stopped driving it now till I can get it sorted

What type of choke set up do you have?

Automatic choke i believe. I have the throttle control knob in the cabin which I always thought was a choke till I got corrected recently

An update on my Nissan. Turns out it doesn't have an automatic choke. The carby models do but mine being an EFI is controlled from the O2 and MAF sensors telling the ECU how much fuel the injectors need to let in. So I cleaned both of those sensors and now all is well. Had the same original question up on the patrol4x4 forum and after a bit of discussion that's what they came up with  :)

Glad you got it sorted.

Jeff

tadpole wrote on Oct 31^st, 2016 at 8:25am:

An update on my Nissan. Turns out it doesn't have an automatic choke. The carby models do but mine being an EFI is controlled from the O2 and MAF sensors telling the ECU how much fuel the injectors need to let in. So I cleaned both of those sensors and now all is well. Had the same original question up on the patrol4x4 forum and after a bit of discussion that's what they came up with  :)

May I suggest REGULAR cleaning of the MAF ?
I clean mine every 10,000 K's and have never yet had any issues with it whatsoever.

Yeah I have a can of MAF cleaner now so it will become a part of my service schedule. As well as cleaning the oxygen sensor. The car has been running sweetly since doing this 6 months ago. Couldn't be happier with the old girl