Misfire on part throttle

[wixer]

Problem with my van,a 2.1 injection. It's worse when cold and virtually non existant when upto temperature. Under part throttle it's misfiring, which can usually (but not always) be cleared by flooring the throttle. It also occurs when under load, again when cold. Strangley it doesn't do it everytime, which is the annoying bit. I've looked around the engine bay for anything amiss but everything seems fine. I've also by-passed the idle stabiliser control unit but this hasn't helped either. I've also cleaned the idle valve with carb cleaner.

Any ideas ? I don't really want to start the expensive process of replacing things till the problem's solved.

Thanks

[Fritz]

You are gunna have to start some where so I suggest checking or at least replacing the ignition leads unless they have bee changed in the last 3 months or so.

The symptoms you describe can be attributed to faulty/damp leads...


Regards

Fritz,,,,,,,,,,

[wixer]

Yes, new leads were first on the list of things to replace, they look as though they've been on for years.

[kevtherev]

Well once all the electrical avenues are exhausted
(check inside the coil where the king lead fits for debris)


then I suppose it's a fueling problem.
(filters ok? no water in the fuel?)

[big red bus]

Start wth basics, plugs + leads, check distributor cap and rotor. If all o.k check coil lead connnection. May be worth changing the coolant temp sensor as well, they are cheap and will help improve overall running. good luck

[toomanytoys]

Full throttle places the most load on the HT system... if its working there then I doubt its an HT problem...

Sounds like there is a small problem with a temp sensor...

I would prob go round all the connections on the engine, temp sensors, injectors, etc etc... and unplug and plug back in 1 by 1 (at least a couple of times)... a squirt of "contact cleaner" will help... check all the inlet pipework for leaks... check any wiring to each component for small cracks and damage also...

[lambrettalee]

Air Leak...............

[wixer]

Thanks for replies so far.

Temp sensor changed last month when engine tuned. New fuel filter also. Changed the fuel filler neck rubber a couple of months ago aswell, so doubt whether there's water in the fuel and if there is, I would've thought symptoms would be there all the time.

I'll go through the usual checks then, leads, connectors, hoses etc. What about air flow meter ? Do these suffer as they get older ?