My 4x4 saff has started idling very rough going up and down between about 300 and 1600 rpm and sometimes comes down far enough to cut out, it also missing in midrange but ok low down the revs.
Any ideas what I can check that might be casuing it pretty sure its not plugs as I just fitted a new set of 071's and thought it might be them so then fitted a new set of champion 59's which is what was in before but its still the same.

Thanks in advance for any advice.

 

Please help need to try and find fault tonight if possible.

 

Clean out your iscv.

 

you also need to check the base idle setting, get the car warn, make sure all electricals are turned off and dissconnect the iscv, the car shoulkd idle at 850rpm, if not you need to adjust the idle.

 

Has the car had a soaking? The vents line up nicely with the iscv and the two wires can ocassionally short with water that gets onto them. Dewitts always dried them and covered them with vaseline on the race cars to avoid what you describe.

 

The fact that the idle raises shows the iscv to be ok, it cannot make it drop(below base idle) so there is another problem, I would check CO, as if lean it will cause all sort of problems, if richness causes it I would expect you to have more syptoms /
Look also for any air leaks, check the usual plug gaps leads etc.
tabetha

 

what would be a rough guide for the co level, the car is running a t34.63 with greys and if anything was to rich, however when I took it for mot recently it past the emissions which it could not do last year, what could cause it to start running lean without anything being changed.

 

Clogged up fuel filter.

 

Never got a chance to check anything last night but I never thought about the fuel filter.
That could deffo cause the symptoms I,ve got, would I be able to pick 1 up at halfords or somewhere similar,ifso I'll get one on me home from work.

 

Probably m8,ford sell them quite cheap.

 

dont think I would get to dealer before the parts counter shut

 

When i needed one for my cossie mate i went to every motor factors in darlo and no one had one. Motorscope in northallerton had them on the shelf.

 

Chek for air leaks, I had same problem, found the leak and that solved my problem

 

So far I have fitted a new fuel filter, cleaned the crank sensor, checked the clearance on the phase sensor, checked rotor arm and dis cap etc, checked the connections on injectors, checked the 3 multiplugs on the bulkhead.

I have also noticed when the revs are rising while idling there is a bit black smoke coming out.

Still no further forward, any other ideas folks.

 

water temp sensor

 

How would that effect it out of interest and would that have any effect on boost pressure.

Is there way to test it or doneed a naw one to try.

thanks

 

it would affect the cold start map amongst other things, unplug it and see if it makes a difference to the running. If not then its probably knackered.

The ECU uses that, air temp, amd map sensor to get the mixture correct. I think you have exhausted most of my 1st choices of things to check so its worth checkign that AND the map sensor.

You can run a multimeter across the pin outs in the ECu cover to ceck if its with the correct parameters also think it should be between 0.3 and 3v IIRC.

OR stick it in a pan of water and check the resistance while heating the water up.

Should see 6K Ohms to 0.27K Ohms between 10C and 90 respectively

 

Just stopped raining so I'm going to do some more checks, just so I can go straight to it where is the temp sensor situated.

 

at the back on the inlet side of the head its a BLUE plug bleow the water pipe to the heater matrix

 

cheers i will go and give it a try

 

does the idle smooth out once the car warms up? mine is doing the exact same thing but idles fine when warm. we just figured out last night that i have a bad intake air temp sensor. when my engine coolant temp sensor was bad, it ran so rich that i would have to pull the plugs and clean them after every third start.

 

I've had a feel around and pulled the plug off of the temp sensor and it didn't change the way it was ticking over, the plug itself is half missing aswell so I don't know if its getting a good connection or not.

I can't really get my hand in cause the breather tank is in the way so I will jack it up tommorrow and have a look from the bottom, if I need a sensor are they are dealer only part.

 

you can get them from Ebay very cheep.

best bet is to check the sensors at the ECU multi plug to rule out the sensor and the wiring for MAP, ACT and ECT

 

No you can get one from matt lewis m8.

 

It still does it when it warms up.

I think matt lewis does a full sensor kit on ebay for £85, I might just so say sod it and change them all as I need a fan switch aswell

 

http://www.bigturbo.co.uk/

you can che the sensors/pin outs on the site above and expected voltages for working sensors

 

i had the same problem on my old 4x4 saff and it turned out to be a leaking inlet manifold gasket