Failed the MOT

[ronnie1995]

Could be caused by an air leak, leak in exhaust system, ignition timing. I'd clean the carburetor first off.

How can the ignition timing be adjusted?

[planetc]

Without hearing or seeing it we can only guess. Common things that lead to crappy idle could be, iac valve, air leak on intake manifold or pipes, egr fault, map sensor, a dizzy cap that tracks on the back of the king lead connection or the tank vent valve leaking. Not so common would be a valve that isn't sealing properly or even a piston ring. How did you get the co down in the end? Or did you just have an understanding tester that was very helpful

[planetc]

Have you looked at the cts, thinking aloud, rich mixture and crap idle?

[ronnie1995]

Without hearing or seeing it we can only guess. Common things that lead to crappy idle could be, iac valve, air leak on intake manifold or pipes, egr fault, map sensor, a dizzy cap that tracks on the back of the king lead connection or the tank vent valve leaking. Not so common would be a valve that isn't sealing properly or even a piston ring. How did you get the co down in the end? Or did you just have an understanding tester that was very helpful

Okay, would a video recording be of any help?

Because of the year my car was built it isn't a legal requirement to have the cat fitted.

Okay, what is a cts? (forgive my lack of knowledge lol)

Also its been suggested the the breather pipe that comes from next to the oil dipstick to the front of the engine could be blocked up, likewise the mesh under the rocker cover. Is this a likely cause do you reckon?

Cheers

[planetc]

Blocked breather could mess with the idle yes. Video might help, but there is no substitute for actually being there tbh. Cts is coolant temp sensor

[ronnie1995]

Blocked breather could mess with the idle yes. Video might help, but there is no substitute for actually being there tbh. Cts is coolant temp sensor

Okay, took the breather pipe off and wasn't blocked up just had oily residue.

Heres a link to a video of the engine running and of the putting from the exhaust: https://www.dropbox.com/s/f4uuldbqb69h3 ... 4.MOV?dl=0

Also whats an iac valve?

Cheers

Ron

[ronnie1995]

The link on the last post didn't work.
Heres a working link to the video of the car running: http://vid32.photobucket.com/albums/d50 ... a6ec88.mp4

Cheers

[planetc]

Difficult from that, but it sounds pretty shagged, like a well abused engine. Disregard most of the list I posted before, as I can tell from this it's not going to be most of it.
It's very noisy, but I can't tell from the video if that's just because you have removed the original airbox. It almost sounds like the cambelt timing is out, it's that noisy. Popping back in the exhaust at idle would be something I would associate with a poorly seated valve. I would be interested to see what the state of the camshaft and valve gear is.

[ronnie1995]

Okay, yes definitely doesn't sound right.

Could this pipe have something to do with anything?



Cheers
Ron

[Cavalier342]

If you mean the rigid plastic one in the middle, that's the brake servo vacuum pipe.

[ronnie1995]

If you mean the rigid plastic one in the middle, that's the brake servo vacuum pipe.

Okay, as the small pipe underneath is removed, covering the hole up changes how the engine runs. could it also be possible that the pipe is partly blocked?

Cheers

[iangsi]

[/quote]Okay, as the small pipe underneath is removed, covering the hole up changes how the engine runs. could it also be possible that the pipe is partly blocked?

Cheers[/quote]

Probably not the pipe the thing it was connected to

[planetc]

That looks like the pipe that goes to the tank vent valve hanging down, and it should connect to the servo pipe? The tank vent valves often leak and cause an air leak on no 4 cylinder, which would fit with what you just said.

[planetc]

Follow the pipe, you'll find a little black starship enterprise shaped thing, that is the valve.

[ronnie1995]

Good News!! The problem has been solved!

It was that pipe that goes from the servo with the non return valve in the middle. Replaced the valve and pipe and is now running sweet as a nut.

I am extremely pleased with how well it is now running.

Many thanks for your help!

[planetc]

Good stuff, glad to hear it's sorted

[cavalier1990]

Hi there,
After swapping the injector unit and map sensor over, it still hasn't made a difference to the running of the engine.

However there is good news, it has now passed the mot and is drivable. just not running as it should.

Has anyone got any other ideas as to what could be the cause of this issue?

Cheers

Ron

Hi Ronnie

Did you swap both at the same time or one at a time to see what actually solved the problem? Reason I am asking is I have the 1.8 Cat model and can't work out why my emissions are failing. Tried a whole host of things (cat, oxygen sensor, service, check all pipes etc.) but not map sensor or injector. My engine runs fine and plugs are clean. well to be honest the only thing is my engine sometimes drops revs and revs up to about 2500rpm when I am moving, but 99% of time it's fine and get good mpg.

Do you have single point injector in the centre of carb?

Andrew