backfires

[cssuk]

hi i have a nissan patrol 4.2 which is dual fueled, on lpg i get a backfire on overrun but its ok on petrol i have only noticed the problem since i had a stainless exhaust made and fitted last week i also removed the cat at the time but made sure both lambdas were ok one for the standard system one for the lpg any ideas? ohh btw it sounds like the dogs whatsits with this exhaust fitted fast n furious eat your heart out am also looking for a suspension lift and some bigger tyres i want 33s after a 2" lift any idea where to get the wheels? suspension is ok i have ironmans on order, finally it will be in the bodyshop in 2 weeks to sort the arches cutting out the rust and fitting new and fitting new bumpers anyone any idea where i can get the seats recoverd? cars mechanically perfect fsh but as an ex farmers its shall we say cosmetically challenged!

 

[Deleted Member S]

Regarding getting your seats retrimed I would have a look in your yellow pages for coach trimers or you may find someone one the net :smile: The price will depend on what you want ie 1/2 leather & fabric, full leather etc. If you have time & a sewing machine you could do it your self which will cut the costs alot as you can use the old covers as a template :smile: I will be doing this when the sides of my seats start looking shaby or tear & will replace them with leather or a good leather look vinyl.

 

[(RIP) PLANK]

hello, if you add your cae details to you info at the bottom it makes answering questions easier.

is it carbs or injection, has it a new sequential injections se up for the LPg or and onl venturi type system?

if it is injection does it have an old external bosh type air flow meter?

it sound like the later, a bosh type air flow and venturi set up, as that i have found tis the usual cause of back firing on LPG, there should be a valve or two in the pipes from the atomise to help with htis,, but, and a big but, i have had this issue with big exhausts on petrol range rovers with older lpg systems and never solved it, it can untimately start wrecking the air flow meter!

 

[Terranosaurus]

As plank says but also is it a true back fire in the inlet or is it down the exhaust on over run? mine does both at times but the on over run down the exhuast only happened when the exhaust manifold was cracked or when the down pipe comes loose - basically when there is a leak in the exhuast system - so since you've just had a new exhuast fitted, wonder if theres a leak at one of the joints.

 

[cssuk]

hi its efi hence the cat and lambda, so what your saying is that the exhaust is/may be the cause? the actual bore is the same its the silencer which was also custom made which gives it the noise, i have however also noticed a strange noise underbonnet at around 1800 rpm which may be an air leak and causeing a weak mixture will have a prod around this weekend with some carb cleaner, another issue i have is the rear diff lock it dont work in any gear incl 4L anyone any ideas where to start on that one?

 

[(RIP) PLANK]

i am unfamilliar with the EFI on a patrol what is the set up? same for the gas if it has been recently installed and is a later sequential injection system it nees setting up on a computer, but earlier systems have some adjustment.

 

[cssuk]

no was fitted by the previous owner 4 years ago its a romano system probably single point but it does have its own lambda and ecu think i will just have to take it to a gas specialist anyone any clues on the rear locker? also it doesnt say anywhere do these cars have a centre diff? ie can they be used in 4H on tarmac?

 

[(RIP) PLANK]

i have the romano software on this laptop and the leads but it isnt much help to you al over ther is it :?

 

[BIGBADWULF]

dont use it in 4wd on tarmac mate. when in 4wd it sends 50/50 to
front and rear and will blow something on the road. does your difflock
not work at all or is it just slow to kick in? it wont come on above 10
mph i think anyway? if it isnt working at all it will either be stuffed
solenoid or a leak somewhere in the vacumm pipes that lead from
the solenoid on the diff, back to the engine bay. sorry, dont know
anything about LPG, tho someone once told me it needs a better spark than petrol? and bad running can be cured by better sparkplugs and leads???

what sort of wheels do you want, steel or alloy?

 

[BIGBADWULF]

hey thought i'd seen you somewhere else, is this yours?


http://img4011.photobox.co.uk/47602...b1a6fc24bbf015333950c967b5d7273db487848f6.jpg


was out with les, who you may know, on sunday :wink:

 

[cssuk]

yep thats me wanting steelies but i want chromed ones( ok ok so its bling) in 8x16 to fit 33s the rear diff no indication on the dash no clicks etc i can hear will have a look at the pipe this weekend whilst i am trying to fig out why i have no brake lights i had em but plugged the caravan socket in backwards (oops) fuses are ok but no lights hopefully the switch which i got today off nissan

 

[BIGBADWULF]

when i was looking for new rims, chrome was really difficult to find, i
went for white 8 spokes instead. chrome soon rusts and pits anyway
and they wont give you warranty against it. only a couple places said
they could get chrome, think 4x4at could and LA supertrux.

like i say, i went with 8x15 whites, with a -25 offset to help the 33's
clear. be careful tho to make sure when you buy that the centre bore
is big enougth to clear the patrol hubs as some wheels aren't.
111mm is what you want

 

[cssuk]

either theses

http://www.offroadmdg.co.uk/html/street_locks_5_6_lug_only.html

or these

http://www.offroadmdg.co.uk/html/chrome_modular.html

they dont list the right offset but i can get them elsewhere just not sure of the type i know they will rust so may even get alloy in which case it would be

http://www.tyresave.co.uk/alloypix/big/dakar.jpg

 

[BIGBADWULF]

think what the problem there is they are listed in the
american spec, i dont know how to convert it, but i like
the look of those black ones!!!! 8)

could be worth an email to them to check specs?