Clicking surging and revs dropping

[besidetheseaside]

Hi Guys, Hope everyone is safe and well and not bouncing off the walls with boredom
Car has as ever been ultra reliable, starts first time and ticks over like the proverbial..... However yesterday it started up then cut out so I knew something was amiss, kept cutting out until I managed to keep it running and lifted the bonnet. Strange set of symptoms, revs dropping then surging all in time with a distinct clicking sound from the engine I have googled it and got a few tips, I will start and see if I can pull a fault code first then check all the obvious bits. Symptoms were the same as I was driving the car so temp made no difference, I stuttered into Rhyl and stuttered back home. Any pointers will be gratefully received so I can spend less time out in the cold
Many thanks, stay safe, Don.

[Laird Scooby]

Originally Posted by besidetheseaside

Hi Guys, Hope everyone is safe and well and not bouncing off the walls with boredom
Car has as ever been ultra reliable, starts first time and ticks over like the proverbial..... However yesterday it started up then cut out so I knew something was amiss, kept cutting out until I managed to keep it running and lifted the bonnet. Strange set of symptoms, revs dropping then surging all in time with a distinct clicking sound from the engine I have googled it and got a few tips, I will start and see if I can pull a fault code first then check all the obvious bits. Symptoms were the same as I was driving the car so temp made no difference, I stuttered into Rhyl and stuttered back home. Any pointers will be gratefully received so I can spend less time out in the cold
Many thanks, stay safe, Don.

When the power was lost Don, did you notice if the rev counter dropped to zero? Did the clicking sound coincide with losing and regaining power?

If the answer is yes to either of those, two things spring to mind, first is the CPS mounted on top of the bellhousing, second is the fuel pump relay has become loose in it's socket in the central electrical board behind the ash tray.

Both fairly easy to check, fuel pump relay can be checked for looseness by simply pushing it back down into its socket, the CPS needs tyou to bend over to see the CPS, the wiring is likely to be in a poor state of flakiness and if so i'd suggest renewing that just to be on the safe side.



That was my old one when i retrieved it and how it should look :



This shows the location, you can just see the CPS slightly to the left of centre and up a smidge under the inlet manifold :



Yours will be different and probably a bit easier to find as you have a red block, mine is a V6 so the inlet manifold is in the centre of the engine. Also the lead on yours is longer but other than that they're the same electrically.

If those things check out ok, let us know and we can think of other things to check - while you're under the bonnet, check the security of the the HT king lead/crown lead between the coil and dizzy - if that has come loose it will give the same symptoms.

[besidetheseaside]

Thanks Dave, I didn’t notice the Rev counter as I was under the bonnet listening to that clicking. Just waiting for the rain to stop before I get outside, just ordered a CPS as at 27 years old it is probably on its way out anyway !!

[besidetheseaside]

Checked the fuel pump relay in fact changed it for a new one I had in as a spare but there was no change. Symptoms have changed, now when it starts it revs to about 2000 rpm then cuts out. Freezing cold out there so I have retired to the warmth of my lounge to beat the rain, will do some more delving tomorrow.

[Laird Scooby]

Originally Posted by besidetheseaside

Checked the fuel pump relay in fact changed it for a new one I had in as a spare but there was no change. Symptoms have changed, now when it starts it revs to about 2000 rpm then cuts out. Freezing cold out there so I have retired to the warmth of my lounge to beat the rain, will do some more delving tomorrow.

See how you get on with the new CPS Don, meanwhile stay snuggled up in the warm!

There is something else that has come to mind if it will only rev to 2000rpm and that is the TPS - if the idle switch is sticking on it will prevent the ECU changing to the "running" map from the "idle" map so won't allow the extra fuel through to run. There's also another thought that has crossed my mind but let's not think about that one for now!

[besidetheseaside]

Hi Dave, would you have time to watch a video of my engine running. If so could you pm me your email address and I will send it over. Tried to upload it here but it wouldn’t accept. Many thanks, Don.

[TonyS9]

Which car/engine?

[besidetheseaside]

Originally Posted by TonyS9

Which car/engine?

Volvo 940 turbo 2.0 1993 Wentworth

[Laird Scooby]

Originally Posted by besidetheseaside

Hi Dave, would you have time to watch a video of my engine running. If so could you pm me your email address and I will send it over. Tried to upload it here but it wouldn’t accept. Many thanks, Don.

PM sent!

[besidetheseaside]

So took the dizzy off just to make sure and that is perfect, did a code check and 232 came up so that us where I am aiming for next few hours, h20 sensor, exhaust gasket leak, MAF to clean, and google it