timing problems.

[adam459]

hi, i'm having a little trouble with my ignition timing. at idol i'm setting it at 10-12 btdc and at 26 btdc at 4000rpm with the vacuume pipe off and it still runs like a sack of crap. does any one have any suggestions on how to sort this (appart taking it to a garage cos i took it to a main tvr dealer and i got it back in the same condition they said they could not find the problem). thanks, adam.

[GreenV8S]

Those figures aren't unreasonable, although there's always the chance that your reference marks are out. What are the symptomsw?

[adam459]

I've still got a misfire, when the car is at tick over and i put my foot hard on the accelerator it coughs and splutters before it builds up rpm and i also have bother starting it. I've changed the dizzy cap, coil, ignition module, ht leads and plugs. my automatic advance seems to be working cos when i have the timing light on and i suck on the pipe the tdc mark moves back. really quite stumped now.

[GreenV8S]

If it normally runs OK and you've check that the timing is consistent using a timing light then I'd suspect that the running problems are fuel and/or HT faults rather than a timing problem. Unfortunately the symptoms are too general to even guess at the cause without more investigation.

[blitzracing]

I had very simular problems on my V8 Ginetta, that turned out to be muck in the fuel filter(s) as the tank had corroded in the winter and filled them rusty sludge. The problem shows up under acceleration as the fuel pressure needs to rise to the injectors as the inlet vaccume increases, and puts greater demands on the fuel supply to the injector rail.

[brummiewedge]

you didnt say rotor arm too? I had a new Intermota thing and it fell apart, i replaced with a proper one and it cured my low end running. My timing is at 12 and 28 so your not far away. Also Bosch plugs were pants, 10 quids worth of NGK always works well.