Kangaroo starter

[TurnipSpeed]

Hi, my 940 2.3 lpt 95 m reg has developed a bad problem on
starting.
It judders violently, like a stall, but picks up ok after a few seconds( so far!)
And there is a slight petrol smell.
The temp gauge varies slightly, sometimes reading cool( below middle), and in cold weather the engine revs high( 15-18000 revs), but settles down if I stop the engine and restart.
Just wonder if all these problems could be related( coolant temp sensor? Idle control valve?)
Thanks in advance for any advice, Paul.

[Laird Scooby]

It sounds as if you're low on coolant and/or have an air lock in the system.

The temp sensor for the temp gauge is different to the temp sensor for the engine management, the latter is about halfway along the head under the inlet manifold.

If you change it, go for the genuine Bosch item, for some odd reason pattern ones don't seem to be tolerated by the engine management system.

DO NOT use PTFE tape on the threads, it has a self-sealing design and relies on the metal to metal contact of the threads as the earth for the two sensors inside it - one for the ignition and the other for the fuel.

The idle control valve appears to be working but for some reason, it seems the ECU is getting a "cold engine" signal from the CTS (Coolant Temperature Sensor), whether that's because the coolant level is low/airlocks in the system or because the sensor is belly up, i can't say from here.

Good luck and let us know how it goes.

[Stephen Edwin]

This has the sense of a problem that could become a long thread. I hope I am wrong.

Has the problem just happened or been going on for a while? Has anything occurred or been done to the car/engine shortly before the problem began? Is it an ongoing problem or a one off?

I would begin by cleaning up thoroughly the HT system. Coil and plug leads, distributor cap and rotor arm, cleaning and gapping the plugs, flooring the accelerator when starting. &c. &c. All of that is routine stuff that costs only time and effort. Cushti.



P.s. When I was young, my father's car had Kangaroo Petrol, or so people said ....



.

[TurnipSpeed]

Thanks for your replies.
The radiator has just been changed, but as I mentioned in a previous thread, there is still a water leak around the water pump( which was also recently replaced).
Annoying thing is the mechanic I use is an ex-Volvo mechanic, but I don’t always get a good job done by him.
I have been trying to get the water leak fixed for about 3 years including getting the heater matrix repaired.
Should there be pressure in the expansion tank( there is now, but wasn’t before the rad was replaced)?
And how would I release an air lock in the system?
Thanks for all your input!

[Laird Scooby]

Maybe you've found the reason he's an ex-Volvo mechanic!

As long as there isn't an excessive amount of pressure in the expansion tank, it's good that the system is holding pressure now.

Keep it topped up (check daily before use) and if you can, park facing uphill. That should slowly but surely get rid of the airlock, especially if you set the heater to the hottest setting, don't necessarily need to have the fan going as long as it's set to the hottest to circulate coolant through the heater matrix which will also help release airlocks.

[Ian21401]

Originally Posted by Laird Scooby

Maybe you've found the reason he's an ex-Volvo mechanic!

As long as there isn't an excessive amount of pressure in the expansion tank, it's good that the system is holding pressure now.

Keep it topped up (check daily before use) and if you can, park facing uphill. That should slowly but surely get rid of the airlock, especially if you set the heater to the hottest setting, don't necessarily need to have the fan going as long as it's set to the hottest to circulate coolant through the heater matrix which will also help release airlocks.

Haven’t changed coolant for a while as use Volvo at 50% and if top up needed (hardly ever ) top up with same, but long long ago in a land far far away in the days when I topped up with plain water and added antifreeze in the autumn I was taught to always have the heater fully open when slowly re-filling the coolant then run engine with rad cap off until warmed up, allow to cool then top,up as necessary. ( My cars at that time did not have expansion tanks fitted ) Last time I had cause to drain the coolant, I think that it was to replace the bottom rad. hose, I adopted the same procedure. Plus, when first used thereafter, have heater fully open for a few miles at normal engine operating temperature.