HOT WEATHER START PROBLEM

[sheerwater]

Vehicle 850 2 litre 10valve ''N''reg.
Vehicle always starts AOK in cold weather but as the weather gets hotter (rare for UK!!!) the car becomes more reluctant to start. If the weather gets really hot and the car is left standing without shade it almost becomes impossible to start but will do eventually. Anyone experienced similar probs or can give me an indication as to where to start to look. Cheers Nigel

[markas]

Hi ya,

I have had a look in my copy the TSB list for 850's and there is one listed in a august 96 TSB "Engine - Ignition Conditions and Starting Difficulties" related to this problem. This is the extract from NHTSA website:-

ENGINE DIFFICULT TO START OR IGNITION CONDITIONS CAUSE THE GROUND TERMINAL ON THE CHASSIS &/OR EXCESSIVE VOLTAGE DROP ACROSS THE CONTACTS FOR THE IGNITION COIL & IGNITION DRIVER STAGE DUE TO OXIDATION.

A couple of things to check first i guess are the plugs OK, volvo came out with the 3 electrode version to help with this problem on 20v, i use the bosch 4 supers myself.

Next check there is no corrosion anyway and every thing fits probally. If might be worth popping the ECU and cleaning the edge and reseating.

Hope some of this helps,

Mark.

[sheerwater]

Thanks Mark, its a start anyway. Its probably something very simple. The other thought was the fuel tank ventilation breather being blocked causing a slight up on the backflow and therefore lower or higher pressure at the injectors. Cheers Nigel

Try fitting the three electrode plugs (if you don't have them already), I have these now and they definately make a difference when it comes to starting up, hot or cold.

From memory they were about £15 from the dealer.

Worth a try !

[Simon Linton]

You could also check when the throttle body was cleaned; this can cause starting and running problems.

[sheerwater]

Thanks, will try the throttle body first! Cheers nigel