Start by giving the ignition system a good service.
How do you know that the temperature sensor is functioning correctly?

 

took the sensor out at tested its resistance a certain temperatures, against some figures i found on this site. i think a dizzy cap and rotor arm might be in order as its had leads and plugs.

 

Yeah, as Diesel says, a rough idle screams HT leads to me. I've just bought some new ones for mine as my ZS was running a bit "lumpy" in the cold/mornings/damp/etc.

I'll prob do the spark plugs again too, even though I only changed them in January (I've had coolant leaks/inlet manifold gasket probs so think those spark plugs are probably shot now anyway).

 

Hi

It sounds like your timeing is out by 1 tooth. I had all those problems about 4 days ago, I adjusted the timeing and sweet as a nut. I tried the HT leads and sparks, they helped a bit but the timeing was key. A socket set some small spanners and a 22mm socket is all you need to sort this out. You can get a cam locking tool but I did mine without I just had to be careful.

When doing a HG is they don't recheck the timeing (a lot of places don't) it can slip out by a tooth, the car will still start and run but you will get all of the symptoms you descripe.

I bet when you turn the engine onn it jusdders around 500 revs before getting up to the 1k mark.

the car had done just 10 miles since the head gasket was done!
since driving the car for a few weeks i have noticed a few problems,
fuel consumption excessive i.e. 25mpg
rough idle once warm i.e engine shakin
every so often the engine stalls when depressing the clutch when pulling up to traffic lights

 

I think that is a good point. I didn't pick up on the gasket change bit.

Just whip the belt cover off and see if all the marks line up.

 

Mine was 1 tooth out on the inlet cam.

Also have makup mirror and small torch at hand it's usefull for checking the timing marks on the drive cam. Once thats lined up right, then the top two cams should noth point in the same direction, you may need a straight edge to check them.

The drive cam should be a 90 degress to the inlet and outlat cams. Full right lock and removing the rubber guard that attaches to the bumper. There you should get access to the 22mm nut on the drive cam. The mark shoudl be at about the 12:20 position if you cannot find the mark, run your fonget over the edge of the belt wheel you can find the mark with your finger nail, then jam in the makup mirror so you can see the marks from the top, you will need a small torch there, as it's hard to see.

Then check the top two cams are linded up, the marks should be lined up exactly tooth for tooth, if their is a atooth differance then it will require some fiddling, to get the belt off and on and lined up. If you don have a locking tool then get the exhaust cam line up right, and use the belt to hold it. keeping the belt tight line up the inlet cam and use the bet to hold that cam. now you have to get it around the tensioner, this you can do by loosening the tensioner, and a bit of push and shove, then retension.

http://video.google.com/videoplay?docid=4217575705633360863

this video helped me.

 

little update, i hve checked the cam timing which seems to be spot on! does anyone have any other ideas as to what my problem could be! this thing is costing me more to run than my zs 180!

 

car put on emissions tester! and all the results where very low and all well in spec, apart from the lambda which can be between 0.97-1.03 and mine was at 1.03! does anyonew think my lambda sensor could be the problem? car is still using far to much fuel!

 

The lambda is sued by the ECU when the engine is under 3k revs. That could be teh problem if it's on it's way out. it might also be the casue of rough running, as the air/fuel mix will be wrong at low revs.

I know whent he ECU in mine stops useing the lambda, as the sound of teh engine slightly changes. I usually use this noise to see if I'm driving economically, Above 3k revs it's starts to eat fuel and I swear at 4.5k revs I can watch the fuel gadge moving slowly down. I usaully try to stick to 3.5k revs for the best of speed vs fuel economy.

Anyway I think ifn your lambda is being a but funny it might be the cause of your problems.

 

anyone else shed some more light?

 

The lambda sensor is used through out the rev range on all engines as it tells the ecu how high the oxygen content is so it can adjust the air/fuel mixture correctly, that is why it's also known as an oxygen sensor.

This may be part of the problem but i would also service the ignition system. when the HG was replaced was the sparkplugs changed as where i work that is comman practice.

 

right ive been told that a high lambda reading is usually down to an air leak, also my plugs are white which would also indicate air leak! does anyone know where this air leak could be coming from? i have checked over the pipes but cant find anything! could it be the inlet manifold itself?

 

right, little update, ive just done a compression test and the results where a little interesting,

cyl1 175psi
cyl2 150psi
cyl3 150psi
cyl4 175psi

does anyone know if this could be causing my problem or if its nothing to worry about!

 

I have had that problem when the engine dies as your pulling up to lights it could just be a loose connection on the starter, also the timing belt tends to need replacin between 60&70K I had mine replaced when it had done about 68k along with the waterpump.

 

Those results are pretty good and i would not worry about anything there, inlet manifold could be the source of an air leak but these usually are the source of water leaks. Is the exhaust in good condition i.e no blows anywhere because this can cause the lambda to read high on the machine,it can also cause high fuel consumption.

 

Unfortunately, the compression tests just as a figure dont tell the complete story. Did they get there steady, fast, slow etc.

When the HG was done, was it done properly ( done at a garage doesn't always mean properly ). A lower compression test between 2 adjacent cylinders could also mean the HG is leaking between those cylinders or the valves are leaking. All these things could possibly lead to lumpy idle, air leaks etc.