Misfiring

[L500V8]

I took my Griff down to TVR Bodyshop for a twin headlamp conversion and front end respray a couple of weeks ago. When I picked it up last week, I was pleased with the job they'd done, but noticed a misfire that wasn't there before.

I assumed it could have nothing to do with what the bodyshop done, as there would be no need to work on the engine - although it (the engine) did not look as I had left it. (It was cleaner!)

The misfire hadn't cleared when I go home, so this weekend I tried changing the plug-leads as I have had the car 18+ months, and don't know when they were last changed - but no difference.

I checked the plugs, which were changed last service, and the left bank's had some carbon deposit, while the right bank's were also a little bit oily - suggesting weak spark?

The misfire is not related to engine heat, so I assume it's not the coil breaking-down. and seems there all the way up the rev range (although it's hard to tell at high revs). Does this seem likely to be an ECU problem?

[anonymous-user]

Hi Richard,

Saw your car at Langdon Hills today.

The front end looks really smart with the twin light conversion.

Lee

[tvr4ever]

Have a look if they removed the airflowmeter, maybe there is a loose connector there. How's the idling?

Fred

[Trefor]

If it looks cleaner then to me that suggests they've er cleaned it ... and probably used some kind of pressure washing device to remove the bodywork dust. Water has probably got somewhere it shouldn't. Coils do tend to break down on these cars due to the underbonnet heat, but I suggest looking at anything which could have got water damaged.

[Ballistic Banana]

Richard YHM

BB

[mack]

Mine suddenly started misfiring last night-to the point where it would only just start up,wouldn't tick over and sounded like it was firing on three cylinders!
One minute it was running sweet as anything then the next minute I lost all power and ground to a halt.She's just had new plugs,shrouds and a set of magnecors,so,I cleaned the stepper motor (it was quite coked up) and cleaned the crud from the rotor arm and dizzy cap and that's cured the problem.
(I've just got back from a 300 mile run out and she's not missed a beat all day!)
It could be worth a quick check,as there wasn't any signs of a lumpy tickover or poor performance prior to last night

[L500V8]

Thanks, BB & all.

As a result of your messages, I have just rechecked every connection. The lead to the air-flow meter didn't seem to have been snapped home properly, but the main discovery was that the connection to cylinder no. 6 fuel injector was loose. It looked OK, but came straight off when I tugged lightly on the cable to test the connection. Snapped it back on properly and "Bob's your Uncle". Now back to full performance - what a difference!

I hope I haven't done any damage driving around on 7/ 7 1/2/ cylinders?