Running issue - up, down, stumble, stop....

Lewis · Post by **Lewis** » Tue Nov 28, 2006 9:46 am

Hello there,

After driving my new EFi 3.5 back, turned it off for 20 minutes (after driving 120 miles), went back to it and it seems to have developed a small problem.

Got back in, turned it over and it seems to be running on 7? The idle drops to like 400rpm, then it stumbles, ign light comes on, comes back up, stumbles again and will usually drop lower and stall, or not start at all. What an earth? It was fine just a minute ago, has it killed a plug? I've looked through the forums and it seems this might be an ECU problem?

Thanks,
Lewis

(And yes, I realise the cold start injector's off - I did reattatch it for laughs, to no effect. The engine was still warm with some water temperature, too)

Lewis · Post by **Lewis** » Tue Nov 28, 2006 10:19 am

Just spoken to my dad who ran it up to move it this morning, apparently it's hunting, then sometimes picks up the 8th cylinder and runs fine, even idling perfectly.

Could it just be a dead HT lead?

Post by **katanaman** » Tue Nov 28, 2006 10:37 am

Since you just got the car I would recomend you give it a full service. At least then you will know where you stand with parts that are considered to be consumables.

GreenV8S · Post by **GreenV8S** » Tue Nov 28, 2006 10:42 am

It'll be something specific to that cylinder, which rules out the ECU, most of the loom, coil, rotor arm etc. If I were you I'd start by checking that the HT leads are all secure at both ends and all the injector plugs are secure. If they are, try to determine which cylinder has the problem (exhaust header temperatures are a good clue, failing that the plugs will tell you). I'd put clean plugs in anyway since you have them out, this may well cure the problem but if not then swap the HT lead with a neighbour and see if the problem goes with it.

Lewis · Post by **Lewis** » Tue Nov 28, 2006 11:11 am

Thanks very much - I'll look into getting a full service kit, it is on my 'to do' list anyway. Nice fresh oil, plugs, leads, consumables etc.

Does anyone have a recommendation for oil/plugs? I've usually used Halfords classics 20/50 in my other Triumph engines (as per the manual) but am uncertain what would be best for the Rover

GreenV8S, your car looks an utter beast

ian.stewart · Post by **ian.stewart** » Tue Nov 28, 2006 11:41 am

20/50 is fine

ramon alban · Post by **ramon alban** » Tue Nov 28, 2006 4:14 pm

Lewis,
If after checking the things already recommended such as ignition components and you are happy with them and other service items such as oil, filters etc, and your Efi system is still playing up then you may need to perform some methodical checks on the system.

The following link will help

http://www.roversd1club.net/pdf/Article ... Adjust.pdf

Commonly the majority of Rover Efi system problems are caused by faulty electrical wiring and/or connections OR uncontrolled air leaks into the plenum chamber.

Generally, component faults come well down the probability list, but likely candidates would be temp sensor, throttle pot and ECU.

Nearly all the system components can by diagnosed with a simple electrical meter but the ECU is best checked out by substitution.

Lewis · Post by **Lewis** » Tue Nov 28, 2006 4:18 pm

Thanks very much! There's a spare one in the boot, so if worst comes to worse and it's not something simple, I can swap it over and see what happens.

Like you say though, I think it's something simple.

Thanks all!