please help ive got yet another running prob, as always its only when itcold that its worst. it starts ok but when you touch the accelerator the revs drop a bit then when u drive it seems that its missfiring and wont accelerate if u boot it it starts to back fire slightly and miss like hell then when it starts to warm (after about ten mins) it seems to run a bit better but sometimes the revs sit at about 2000 then suddenly drop to normal and if you hold the revs when driving it seems to start missing again power has also dropped slightly please help its doing my head in :headvswal . ive renewed injector which worked for a week and have cleaned some elec connectors which didnt help at all :bow:

Try cleaning the temp sensor connector (yellow connector) on upper rad pipe.

ok thanx will do that now, anyone else have anything to add

sounds a bit like mine did apart from the high revs, was pipes down back of engine water, vacum and 1 that feeds 1 of the turbos. wasnt cheap either mate as there hard to get to, i also had an injector off. but this mite not be the same prob just thought id let ya know

cheers as i found everything with zeds are expensive lol

Yo sorry to hear of the problems with your z ,if you sort it could you post the remedy

as mine is doing the same thing .

thanx for the help everyone been out today cleaning more connectors although most of them wernt dirty. Started with afm connector it was fine, then coil packs then other conns that were about the engine bay. Then i discovered two conns that id never seen before they were on a device that looked like some sort of vavle. It was located down left hand side of battery under the thick black harness cables. It has a blue and a yellow connector on it, i removed them and they were corroded so cleaned them, took it for a spin and it seemed ok was pulling much better and the missfire had gone but engine was warm so will try tommorrow when cold and let u all know how it went :bow:

thanx for the help everyone been out today cleaning more connectors although most of them wernt dirty. Started with afm connector it was fine, then coil packs then other conns that were about the engine bay. Then i discovered two conns that id never seen before they were on a device that looked like some sort of vavle. It was located down left hand side of battery under the thick black harness cables. It has a blue and a yellow connector on it, i removed them and they were corroded so cleaned them, took it for a spin and it seemed ok was pulling much better and the missfire had gone but engine was warm so will try tommorrow when cold and let u all know how it went :bow:

 

Very interested to hear how you get on as I have a similar problem!

started car this morning fired straight up drove well no missing or hesitation when pulling away. BUT on the way home had a race off the lights (silly saxo drivers lol) floored it in first and shot off felt really quick but when slammed into second my cars power died and felt like it was missing like hell and wouldnt accelerate then it backfired and took off again but noticed that it wasnt pulling through the rev range properly had a flat spot around 4500 revs and very slight miss below 2500 revs am suspecting a dodgy maf (probably the running prob that ive had from day one) can anyone shed any light on the situation but is defo running beta when cold

Hello mate.

 

Try cleaning the MAF its self, you will have to take the air intake pipes off to get to, then if the metal gauze is intact take it off then spray connector cleaner on it and clean the pins with a cotton bud.

 

If this fails try replacing the O2's (oxy sensors) My zed had this problem when cold but when motor warms up runs much better, apparently the O2's have heater elements in or somthing if these are broken when the engine is cold it will run like shit, once O2's are warm car runs better.

 

NOT AN EXPERT BUT WORTH A TRY.

cheers will try that

my o2 sensors had been disconnected when i bought the car (did,nt know)when i realised had a consult done by Dave C , yep both knackered but funny thing is you cant tell, it runs sweet right through the rev range, i,ll get round to replacing them one day but knowing my luck it,ll run like a pig if i do. :headvswal :headvswal

Any luck sorting the problem out mate ?

Iv,e tried all listed above and its still the same.

my o2 sensors had been disconnected when i bought the car (did,nt know)when i realised had a consult done by Dave C , yep both knackered but funny thing is you cant tell, it runs sweet right through the rev range, i,ll get round to replacing them one day but knowing my luck it,ll run like a pig if i do. :headvswal :headvswal

 

 

my o2 sensors are screwed, low down revs are a pig and fuel consumption is out of this world, im getting 60 miles less per a tank as under 3000rpm your car will run rich. im really expecting my spark plugs to be fouled also

how can i check if my o2 sensors are knackered i changed one about 6 month ago but since then have had a decatt which means my exhaust had flanges welded on would this kill them

how can i check if my o2 sensors are knackered i changed one about 6 month ago but since then have had a decatt which means my exhaust had flanges welded on would this kill them

 

 

A conzult is the best way (easiest) they should go from 0.33 volts to somwhere near 2vots when accelerator is depressed,

 

another option is

 

http://aus300zx.neuralmotion.com.au/tech/o2.htm

 

welding would only have killed them if they were in contact with any metal being welded and they got over heated,

will have to get my brother in law to do that check or otherwise has anyone got a conzult in the sunderland area that would be willing to do a check for me

how can i check if my o2 sensors are knackered i changed one about 6 month ago but since then have had a decatt which means my exhaust had flanges welded on would this kill them

 

try Andy p's site in the links

http://aus300zx.neuralmotion.com.au/tech/o2.htm

or

http://zhome.com/ZCMnL/PICS/hesitation/hesitation.html

there is some qaulity info there have took today off to try some things never even thought about spark plugs i changed them about 3 thousand miles ago but if engine had been running rough maybe they r knackered or just simply need a good clean thanks lads :bow:

My problem was caused by a bad conection on the throttle position sensor.

There is a 30 point checklist for this problem on one of the us sites.

All the best with your problem.