Help needed.... Missfire

[itsallyellow]

Bit of a long story this one im afraid.

I haddent driven the cerb for a week and took it out for a drive yesterday. Started first time as usual warmed it up. Drove it up the road still all fine. Then suddenly lost all power and engine died. started again and drove fine. Then started to missfire and had no power. Lifted off the accelerator for about 6 seconds, missfire gone.

It seems to only really happen after Ive put my foot down. I.e pull away from some lights quickly. 1st 6k 2nd 6k etc, then get off the power and when yop go back on it missfires, then will be fine after 10 seconds or so???!!

Has anyone got any ideas what this could be???? ive got a track day on tuesday so time is really tight now!
many thanks
mike

[itsallyellow]

Just had a thought. Now and again(not that often) the car will just die on me. Then it starts fine. could i have "The big fuse problem"????

[Cyclone1]

Could be a loose plug lead or one that is arcing, check them and make sure that they are all pushed into position. Failing that it could be coil pack related or maybe one of the throttle pots has failed. I had a problem a few weeks ago where when under acceleration the car was fine, but if I lifted off and then slowly applied the throttle there was a temporary delay in power and then it would be all "jerky" as if there was a misfire, then as soon as I floored it it was fine, just part throttle or slow throttle application and it was hesitant, turned out to be a throttle pot.

Jules.

[itsallyellow]

Thanks mate. The missfre is a bit more intense i think. as when it happens there is basicly no power. you cant power through it you just have to wait for it to go away!
mike

[headcase]

Possibly big fuse issue, does the mil light come on? Maybe worth checking for fault codes but does sound like an electric issue.

[keithyboy]

Intermittent complete loss of power does sound electrical to me. Battery connections or big fuse perhaps? When my coil packs broke down it misfired only under heavy load (i.e. heavy right foot!) intially, then got worse as it got hotter the more the engine was run.

[itsallyellow]

Yea it missfires even under very light load!!!! very intermitent!!

[GreenV8S]

If it comes when you open the throttle and clears immediately you back off, it might be fuel starvation but more likely an ignition problem leading to a weak spark. This used to be a symptom of points on the way out, although of course this doesn't apply to a Cerbera.

If the symptoms change more gradually and take several seconds to react when you open or close the throttle then I'd suspect an ECU/sensor fault leading to mis fuelling.

Your best bet is to get an expert to look at it. There's a danger that you can do more damage if you keep driving it, so I suggest you drive it as little as possible until it's fixed and do your best to avoid situations where it misfires.

[gazzab]

check the ecu is connected properly and is dry?

[itsallyellow]

i cant see what has caused the problem to uddenly ocour. the only thing i can think of is that the car has been up on axle stands at a 40 degree angle for a week????

[GreenV8S]

itsallyellow said:

I cant see what has caused the problem to suddenly occur.

May not be something that you've just done to cause it. Components fail from time to time. The fact that it was driving normally and then suddenly started playing up suggests that this may just be one of those things.

[jensena]

If it's been at 40 degrees for a week, I suppose its possible that some 'crud' from the bottom of the tank has shifted, and found its way into the fuel line - just a thought

[itsallyellow]

i did think of that. would the missfire be intermitent though??

[Cyclone1]

itsallyellow said:

i did think of that. would the missfire be intermitent though??

Yes it would, but as GreenV8S has said it sounds as though more like a component failure of some sort, or an electrical gremlin, I am more inclined to think the former.

Jules.

[itsallyellow]

could an injector failing cause this??

[Cyclone1]

itsallyellow said:

could an injector failing cause this??

If an injector failed then the car would be running a lot rougher than what you've described, missing all the time ad feeling well down on the power you are used to, plus I don't think it would be intermittent, but that's more a case of worst case scenario, if you've done all of the "easy" checks to get to the root cause of the problem, then best bet will be to get it to an Indie to get it looked over, the vast majority of the time these issues tend to be something simple

Jules.

[itsallyellow]

thanks mate.

[itsallyellow]

Well i took it on a long drive tonight. To be honest it seems to be getting better. The only timne it did it in 25 mins of driving was twice and i was able to power through it. However im not sure the car feels as quick as it did?? but i say that all the time!

Should i just take it on my track day and hope for the best?
thanks for all your help.
mike

[headcase]

well, if youve got a dodgy lambda then you could set your cats glowing!

[itsallyellow]

i havent got any cats