The pain-in-the-neck misfire got worse yesterday - generally sod all power, lots of misfiring at low RPM etc. Still managed 16mpg on gas though!
Anyway, would this explain it?....
I'm guessing that this is the vacuum advance, and that it won't have much vacuum in it!
It's been misfiring a while, but it certainly wasn't this broke last time I looked. P'raps it's been buggered a while, but has only just completely broken free?
It certainly would! totally screwed up timing (against load) and I was going to say a weak mixture but that looks like a closed-loop stepper motor in the foreground. AEB system, is it? If so, mixture will be ok as long as within upper and lower setting limits of mixture correction. (steps open/closed beyond default).
Badger.
It's like someone sneaked a 4.6 in during the night...
Very much better, although I suspect that the compromise timing Warren set between gas and petrol is now wrong - it's noticeably smoother at high revs on gas than petrol (which is no bad thing really). High RPM on petrol produces a pronounced rattling under the bonnet, which I guess is pinking.
This is the first time I've really been able to rev it since the new cam went in. It goes right round to 5000+ without complaint (on gas anyway), whereas I never got past 4750 on the old cam without taking pity on it and shifting up. There seems to be a limiter at about 5200
- does that sound right?
On the way back home it was back to its old ways again, which was explained when I lifted the bonnet to find the pipe had come loose again! It's now undergoing superglue treatment.
Thanks Badger. I reckon an RPI ignition amp may be the way to go now to get it right on both fuels.
Haha. I wish that would happen to my 110.
Possibly.
On a std vehicle there's no limiter, the hydraulic lifters will eventually start to pump-up and act as a form of limiter by preventing the valves from fully closing! Very, very bad for the valve seats. Normally happens at anything from 5400ish upwards.
Right, so it wasn't a deliberate cross-check to confirm the diagnosis then? Teehee.
My 3.9 runs a modified dizzy that seems happy enough on petrol and works well on gas, but if you feel the need to part with your money to that "nice" Mr. Crane, then so be it. What's the software on the laptop, is it AEB Leonardo or OMVL Millenium by any chance? Badger. B.H.Engineering, Rover V8 engine builders. Landy 110 3.9V8 Auto, on gas. BMW330dSE sport auto, on speed!
What's the alternative? And how much would it cost?
Don't know - I'll find out.
On or around Mon, 3 May 2004 17:30:38 +0100, "Badger" enlightened us thusly:
The one you sold me was similar, ISTR. less mechanical advance, mainly, isn't it? seems to work, anyway - when the engine's operating correctly that is...
Here's what has been done to the dizzy on my engine. Been fitted now for at least 4 years with no probs. I seem to remember the dizzy I sent Austin had the same treatment, I think. Dismantle dizzy, build up approx. 2mm of weld on the peg that forms the max advance stop, this limits max mechanical advance by approx. 10 degrees. (LPG needs more advance at lower rpm's but less at higher!!) Now fit slightly softer advance springs, to allow it to advance at lower rpm, refit dizzy and time to approx. 10-12 degrees btdc. Job done. Real Steel used to sell dizzy springs. Your dizzy has a soft and a strong spring, initially replace the strong one with something slightly softer. As to cost, a few quid for the springs and some of your own time? Not that difficult and not worth the cost of sending it to somebody to have done for you, I wouldn't have thought. FWIW, my mate runs a modified 3.9 built by myself in a hillrally motor, using a DTA Race management system. It's running about 45 degrees advance in the mid range on pump unleaded with no pinking!
Ok.
Badger. B.H.Engineering, Rover V8 engine builders Landy 110 3.9V8 auto, on LPG. BMW330dSE sport auto, on something!(Valium?)
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