When my car is started from cold, it appears to struggle to feed enough fuel through to keep the engine running. As strange as it may seem, this problem gets much worse if the steering wheel is turned towards full lock on either the left or righthand sides.
I have had some great advice offered, which has resulted in replacing a full set of plugs, leads, fuel filter and a water temperature sensor sited at the rear of the engine, but sadly, all to no avail.
I would welcome any thoughts or suggestions in order to diagnose the problem, or can anybody let me know of an independant garage who have diagnostic facilities available?
Turning the steering wheel will give the PAS pump some work to do which will put a load on the engine.
It sounds like a cold start enrichment or idle speed problem to me.
Is the problem still there when the engine has warmed up?
Does the idle speed increase when the Air Con is switched on or the blower fan is set to 2 or higher?
I would suggest getting the air valve and the idle speed controller checked over. Also, have the ECU checked for fault codes and if all else fails then have the fuel pressure checked.
The air valve should be the first thing to look at because this only affects the running of the engine when cold. A used air valve costs £25 + VAT from AutoLink.
Thank you very much for your response to the fueling problem with my much loved MX5.
My mechanic has checked out the idle speed contoller, which appears to be up and running ok, but I will immediately I will pass your comments on and ask that he checks the other items, in an attempt to sort out the problem.
I think that the idle speed controller only comes into play when the engine is warm and things like the air con, heater blower and headlamps are switch on. If the idle speed is stable when the engine is warmed up then this component is probably working as it should. The air valve is a separate component that increases the idle speed when starting from cold.
Not sure if your MX5 is one of the early cars with pop-up headlights (Mk1) or the Mk2 with fixed headlights. The Mk1 has two water temperature sensors, one for the ECU and one to drive the temperature gauge. The sensor for the ECU is the one that will affect cold starting and running and is the one that should have been replaced if necessary. On the Mk2 a single sensor with two separate terminals drives both the ECU and the temp gauge.
Mine has a bit of a similar problem i think (mk1 1.6 1992) it idles really pretty poorly when cold, sounds quite laboured when i switch on the blower and lights. yet ive set the base idle (when warm i take it?) and it idles smoothly when warm it does drop a little bit if i load it up?
