Running problems

[leec]

Hi guys,

Took my oval out for its MOT yesterday. it passed but on the way back wasn't running too well.

2276cc, IdA's, FK87, Wedgeports, 10.3:1 etc, it seemed to run fine at low revs/moderate throttle but if you floored it it would bog down, then pick up.
Anything above 4500/5000rpm it was very flat, but would try and accelerate if that makes sense. What also happened was the oil pressure guage went off the scale (100 psi ) but this wasnt the case in real terms as it looks like a bit of tinware has slipped and was touching the live on the sender (earthing out)

I haven't had a chance to re-run without the tin hitting the live, could that cause poor running from an electrical point of view?

The last time it was used was in may at Garys picnic but ran two high 11 second 1/4's and has been started and run a few times since. Yesterday saw fresh v-power fuel as well.

Really pissing me off as had an audi tt wanting to play and couldn't educate him on aircooled power...

Im thinking ignition and or carb issue, your thoughts greatly appreciated

Lee

[JezWest]

Whilst I don't recognise the exact situation, and it depends how your wiring is, it is definitely possible that the tinware grounding the live feed could screw up performance. The tinware might be grounding (or partially) the live side of the coil causing a weak or non existent spark.

Look carefully at your wiring though - I shorted engine bay wiring once and all the insulation burned off the one cable in a split second, but it was night time (isn't it always) and I almost didn't notice which would have been bad.

So if you've sorted the tinware I reckon you could well be out educating the unwashed TT masses really soon!

[Stefan Rossi]

I have my gauge wiring in a separate loom so depends how yours is wired up?

What fuel pump are you using? Mine has just sat dormant for a year and the CB rotary pump must of corroded inside or something and it would not work properly. I checked everything on the engine over! Finally found the fuel pump to be faulty and could here is struggling to pump.

Also had the same thing on a customers car the DAY AFTER! Never recommending a CB rotary pump again...

Failing that have you removed all your jets and given them a good clean?

what ignition are you using?

Stef

[leec]

Thanks guys,

should of mentioned it the tinware only touched the pressure sender when I lent on the accelerator hard, which suggests why it was lazy at the top end, ie the guage only read 100psi when pedal hard down! As soon as I let off pedal the guage started to drop down to normal oil pressure.

I'm running 009 dizzy with petronix and cb pump, which is new this year due to failure of recipus one at cal look drag day this year.

Lee

[Stefan Rossi]

Can you explain what you mean by your tinware touching the sender? The cylinder shroud? Can you not tighten it half or quarter a turn so it is not near it?

so is the flat spot still there after you fixed this problem? If you've fixed it?

Stef

[leec]

I've got a t piece screwed into oil warning light hole on the case, the autometer sender screws on to that. The live feed seems to be very close to the front tin (over exhaust next to valance) for some reason. Never been a problem before but maybe it's moved for some reason?

Haven't had a chance to fix it yet, just wondered what else it could be!!

Lee