Intermittent Engine Shut-off
 

Hi everyone. Thanks for the brilliant forum and loads of valuable info.

However, I couldn't find anything on-point with the problem I am having, so I figured to make this thread and see what your ideas are for finding this gremlin.

The car is 2.3l 940 LPT estate. It is nearly stock, only with an MBC and an opened-up airbox.

My first two encounters with the problem were after a wash. The car just died on the way back from the wash when idling at the traffic lights. The engine just simply cut-out as if the ignition was switched off. Everything on the panel lit up as usual. I tried starting it a couple of times, but no luck. Then gave it two-three minutes of swearing and headscratching and it started as usual. The second time the car just wouldn't start after the wash, but I opened up the bonnet, gave it a few minutes in the sun and it started. Then I thought it was some wet connection. But recently the same thing started happening at random. A week ago I went to the shop to get some motorbike parts and as I was trying to drive off, the car wouldn't start, only to find that it did after a few minutes.

Today was a bit different though. It died while driving in third at moderate speed. First time to happen. I turned on the hazard lights and rolled to a halt on the side of the road. Half-a-minute later the car started normal. Then died again when idling at the lights and wouldn't start for a couple of minutes. Also, the lambda light is now lit on the dash.

In general, it works normal and drives fine in between these shut-offs. It has some fluctuating idle, as it did when I got it almost a year ago, but I couldn't find the cause for that. Checked for vacuum leaks, cleaned the IAC, MAF and throttle body, changed some old hoses as well.

Has anyone had a similar problem? Any ideas where I should start looking for the problem? At first I was certain that it was dampness and happened only at idle. Later it happened in plain hot weather and today the only-at-idle thing went out the window.. So I'm confused.

Any input much appreciated. :regular_smile:

Renew the fuses for the fuel pump (#11 & #12 if memory serves) and also renew #1 (ECU memory) and if possible, post photos of the old fuses and the fusebox where they came from.

When i say renew, i really do mean renew, not take out, look at and think it looks ok and replace it - renew them.

You're chasing an intermittent fault here so the only way is to renew certain things to see what difference, if any they make. Testing is of little use for the simple reason until and unless the fault gets worse, by the time you've got the test gear out, the fault has cleared itself. Hence the usual cause for things like this to start with.

I had the same kind of thing going on with my 940 lpt volvo a few months ago, I was pointed towards the fuel relay and told to check for bad joints, sure enough there was some bad joints, I took it to an car electrical shop had it re soldered and checked (all for a fiver), since then the car has run great, hope its that easy for you

And again ( I don't remember how may times)


1!: cps the sensor on top of the bellhousing. ( tacho needle will hopp/jump flicker)


2!: fuel pump relay, the white one

3! Fuel pump in tank, your car is only with this one

4 till .... you won't need at this moment

Grab the wire of the cps and check the condition


Good luck, Kay

They were next on my list Kay! First though i wanted to enure a continuous feed to the fuel pump circuits. Then tacho flicker followed by the white relay............ :thumbs_up:

Could be Radio Supression Relay also. Thats if you have one on your water coolant reservoir.

A valid point but are you saying that if it's not on/near the coolant expansion tank it doesn't exist then? :thinking:

Wot Kay sed.

Really, this is such a standard LH2.4 thing it should be in big, bright lights and wreathed in tinsil at the top of the forum.

If your LH2.4 engine Volvo stops intermittently and restarts shortly after, AND the tacho drops like a stone at the same time DONT check or look at the wiring on the CPS - just replace the damn thing. Relatively easy but take care, instructions here.

If, however, the tacho doesn't drop then check that the HT lead (or "king lead") is properly seated on the distributor cap, bearing inmind that it plugs in atthe bottom of the cap where you can't see it, and that the plug leads are all pushed home. I had this fault with my car and it only revealed itself properly in pouring rain on a dark night as a pretty lights show!

You forgot a couple of things Ash - first is LH2.2, same thing can happen on the and second is the first rule of diagnosis. :tounge_smile: