loss of power when engine warmed up-distributor fault

Post by **vanzep** » Mon May 20, 2013 9:47 am

Got a problem with loss of power on my BB4 once its reached normal operating temp. Was out on Saturday at the workshop and it was running well - plenty of power - got back into town and went to pull away from the traffic lights and there was nothing there - well just enough to creep along. Managed to get back home left it 10 mins went back and it starts up and idles perfect but once its warmed up it feels like no power at all. No rise in revs so cant be clutch can it. I feel it wants to catch so im thinking it must be spark or fuel. Any suggestions on what could cause this

best way i can describe it - there is a change in the exhaust note and it feels.sounds like its running on 3 cylinders

Post by **Lude-dude** » Mon May 20, 2013 11:39 am

checked plug area?

my old leads used to keep popping off the spark plug, leaving me running on 3 cylinders

Post by **NafemanNathan** » Mon May 20, 2013 11:54 am

You haven't tinkered with your valve clearances recently have you?

BMCC · Post by **BMCC** » Mon May 20, 2013 12:08 pm

Is the catalytic convertor still on the car?

Post by **vanzep** » Mon May 20, 2013 12:18 pm

valve clearances were done about 12 months ago
no cat on the car as it got the hytec rep manifold and 2.5" straight thru
leads are on fine - but going to check spark plugs today

could it be main relay on its way out - would explain why it starts fine but not working fully once warmed up

Post by **NafemanNathan** » Mon May 20, 2013 12:27 pm

I suggested valve clearances as I've had those symptons before and they had worked themselves loose and slacked off. Unlikely though after 12 months.

Unlikely to be your mains relay. It's not being able to start the car when warm which is caused by cracked solders in the mains relay.

It could be your FITV is letting in too much air.

Post by **Merlin** » Mon May 20, 2013 12:29 pm

When my main relay was faulty the car ran fine, apart from when trying to start when hot. Do you want to try my spark plug leads to see if that makes any difference? The set on the track car are old but work fine.

If it was FITV would that show itself though affected idle?

Post by **NafemanNathan** » Mon May 20, 2013 12:36 pm

Merlin wrote:If it was FITV would that show itself though affected idle?

Yeah true. My thinking was that the A/F ratio was out, so what could be causing it. If there was too much fuel, you'd be able to smell it, plus it wouldn't start up too well after it was hot, so could it be under-fueling/over air-ing

It wouldn't necessarily hunt, but no it would be revving faster.

Post by **vanzep** » Mon May 20, 2013 12:37 pm

yep idle is fine as is start up - just when u put the foot down its feels like a big sponge

i might try the ht leads - are they at the workshop?

nafe - it could be a fuelling issue of some sort...and the car has a tendency to run rich anyway-hence the flames on overun when its been right up to the limiter

just a bick of fekin pain after its was running so well 5 minutes earlier

Post by **NafemanNathan** » Mon May 20, 2013 12:42 pm

It could be your coolant temp sender or thermo sensor is at fault. That'd cause the ECU to potentially over fuel when warm.