Hey Peter, sorry your having problems with your Terrano.
Is your service engine light on when this happens?
From your post it sounds to be like you cannot build up revs no matter how hard you press the accelerator, is that correct?
Hi Jake, thanks for getting back to me.
No, the service engine light does not come on - the engine just suddenly loses power and has great difficulty getting the revs back up ( but it does not cut out ). After a lot of stamping on the accelerator it staggers up to about 4000 revs which allows me to slip the clutch and stagger on while the revs drop until I have to de-clutch to avoid stalling.
Discovered last night that if I turn the engine off for a few minutes it starts up O.K. and is driveable but with some hesitation and spluttering.
Hope to hear from you, thanks
Thank you Peter, That certainly does help.
This definately sounds fuel related in this respect. While we see MAF sensors cause similar problems it's not nearly as common as fuel priming and SCV issues related to injection pump timing.
Next time this happens I want you to try something for me. Simply pull over and unscrew the fuel cap and screw it back on. Then restart the engine and see it temporarily rectifies the problem.
I am thinking at this point were looking at possible SCV issue on the high pressure pump, alot of times when this is the case the fuel lid trick temporarily clears the symptoms.
So let me know please.
Thanks Jake, I'll try that next time it happens but think I won't switch off first as that seems to cure the problem. Unless you say NO !!! I'll leave the engine "spluttering" and remove filler cap to find out result.
Not too clued up on MAF sensors and SCV issues but it may help the local garage who can only ask that I take it back to them next time it happens, which is only O.K. if I'm just round the corner !
The MAF is just the airflow sensor that detects intake air volume and temperature and responds to the computer so it can adjust injector pulse durations. When they fall out of spec they cause these symptoms. Turning off the engine won't generally correct the problem like it will with a fuel pressure issue though.
The SCV is the suction control valve on the high pressure pump. Think of it like a "throttle" for the injection pump.
Don't leave the truck running, shut it down and releive tank pressure. We just want to see if this helps rectify the problem for significantly longer than just shutting it off alone.
Thanks again Jake, being a bit pessimistic about this (!) next time it happens - today, tomorrow, next week, whenever I'll do as you say and take it from there.
All the best