CwazyWabbit

Nick, Just a thought, the web site says they heat the lines to over 200f in a couple of mins, you could try putting some fuel line in a pan of boiling water for a while and see what happens to it (200f is 93C). But getting the specs would be better. They also show a filter heater on the site, a bit further down the page which looks to be made out of the same wire..... that would suggest your filter wrapping would be fine ..... but just because it looks the same doesn't mean it is, with resistance wire a long length of wire would not get as hot as a short length of the same wire with the same voltage. Have you tried dropping an email to the company?

Thanks for that :-)

Cheers for that western, I checked the RAVE workshop manual for a 300tdi Defender and in the engine tuning data section it states maximum governed no load speed as 4600rpm! That must be a mistake surely? Where does your data come from as it sounds far more plausible than the RAVE manual. My 3800rpm was uphill in 3rd.

Cheers for that, my guess is that the diameter of your crank pulley divided by the diameter of your alternator pulley will equal 3 which would explain why it works for you. But it will be good to get confirmation. Thanks again CwazyWabbit

Mine is now doing the same as yours jad, little under 750rpm cold but 750rpm after a run. :-) Out of interest Jad when you get a moment it would be interesting to know the diameter of your crank pulley and the diameter of your alternator pulley (measured at the top of the ribs). Sounds like the tacho is right for your pulley combination, but it was under reading on mine and is under reading on reb78's. It's good to know it works as standard on at least some 200tdi's :-) From what I have heard there are two different types of 200 tdi crank pulley, I don't know if they are different diameters but they have different locking tools.... maybe you have the older crank pulley (with the slots) and reb78 has the newer one with the threade holes like the 200tdi? that's pure guesswork but may be a plausible reason for the difference.

Just been out for a spin and all looking good :-) Indicated RPM's went up to 3800 rpm before I chickened out as the engine sounded to be going as fast I was comfortable with (never rev'd it that much before based on the sound anyway) When I got back idle tickover was pretty much 750 rpm. I'm happy :-) sorry for all the posts but it helped a lot with the thought process, even though in the end I should have just peeled all the stickers off!! lol. Also working out the theory means I now feel like the guage is properly calibrated and can trust what it is saying.

I found on my 110 that as well as the drive members being worn the half shafts (or whatever you call the bit the drive members fit on) were also worn, it's surprising how a little slack here and there adds up to quite a thud. Have you tried jacking a wheel up and rotating it to see where the slack is?

The adjuster for it is hidden behind a white sticker on the side of the guage, about an inch bach from the front edge and at the bottom (behind where it says vdo) Mine now indicates 750rpm with 196hz and 4000rpm with 1040hz Have fun .... unfortunately I had to take mine apart to find it (stupid moment doh) SO I shall be trying to put mine back together nicely now :-S

Just playing with a few numbers and a multiplier of 3 would work best with my guage.... 6000rpm would give 1800hz 5000rpm would give 1500hz 4000rpm would give 1200hz 3000rpm would give 900hz 2000rpm would give 600hz 1000rpm would give 300hz 750rpm would give 225hz which if you compare with the actuals results from the test I did 6000 rpm = 1726hz 5000 rpm = 1435hz 4000 rpm = 1170hz 3000 rpm = 870hz 2000 rpm = 570hz 1000 rpm = 260hz 750 rpm = 228hz 500 rpm = 163hz 250 rpm = 106hz They are really pretty close (trust me to have chosen 1000rpm for my other post which seems a bit of an anomoly) That would mean I need a 53mm pulley on the alternator :-s ..... what's interesting is the outside lip on the 49mm pulley is 53mmm ..... I wonder if someone made a mistake somewhere along the lines? or maybe they just stuck it halfway between pulley sizes so it was about right? (I really hope my posts all come out in order when the moderator reads them)

So based on my guage, and poor maths.... Actual RPM Expected frequency on W terminal Indicated RPM 750 195hz 600 rpm ish 1000 260hz 1000 rpm 2000 520hz 1800 rpm 3000 780hz just over 2600 rpm 4000 1040hz just over 3500 rpm For a list price of £140 odd punds you would expect a bit more accuracy than that I would have thought :-( So it's not a particularly accurate guage but appears to be designed for the 160mm crank pulley with the 61mm alternator pulley ..... I wonder if anyone does a digital tacho???? (I'm sure the mrs doesn't really want that new cooker....) reb78, hope these figures help with yours.... they seem to marry up with your experience of it. PS I'm currently moderated so my responses take a while to show up ... hopefully they don't get too out of step.

Sorry for all the replies Looks like there are two different alternator pulley sizes available for the 300tdi :- (from http://forums.lr4x4.com/index.php?showtopic=7336) 49mm From VIN TA969103------Pt No STC3202 61mm To VIN MA969102----------Pt No STC1796 Mine has the 61mm pulley which would mean it will read about 20% slower than the 49mm The crank pulley is 160mm (measured from a spare engine, hope there is only one size) so the relative step ups of the two pulleys are (I hope my maths is correct :-S) 160/61 = 2.6 160/49 = 3.25 Now representing RPM in hz (cycles per second) choose an arbitary engine speed of 1000rpm 1000rpm/60 = 16.66 hz Multiply by 2.6 (for 61mm) to give alternator speed 16.66 hz * 2.6 = 43.33 hz Multiply by 3.25 (for 49mm) to give alternator speed 16.66 hz * 3.25 = 54.15 hz From my measurements in previous post (assuming it got approved) to show 1000rpm on an AMR1912 we need 260hz at the W terminal. There is obviously some multiplier affect within the alternator, if we knew the correct amount we could work out which alternator pulley (if any) is the correct one for the AMR1912 to read the correct RPM. Effective multiplier of alternator for 61mm pulley to be correct would be... 260hz/43.33hz = 6 Effective multiplier of alternator for 49mm pulley to be correct would be... 260hz/51.45hz = 4.8 The multiplying effect in an alternator is a product of the number of poles it has, basically a 12 pole alternator has a multiplier of 6 and a 10 has a multiplier of 5. from wikipedia (http://en.wikipedia.org/wiki/Alternator) So the question boils down to is the alternator on my 300 tdi a 12 pole alternator? The general consensus of the web is that most alternators are 12 pole so that would mean after all that the AMR1912 will work fine on my 300 tdi defender..... I better go and wire it up properly this evening :-) Please check my working out, I hope to be corrected if I am wrong.... thanks and sorry for my ramblings.

Hello all, (This is my first post on here so go easy on me) I bought one of these and am only just getting around to fitting it (always seems to be something else I'm 'supposed' to be doing). Anyway I remembered this thread to I hooked it up temporarily first and saw the idle speed was showing a little over 500rpm. Now from what I've read the idle speed should be around 750rpm, so do I believe the guage? I've noticed there is no adjustment on the guage (you can't even take it apart, unless you want to damage the surround) but I did notice a sticker saying 12V/1800HZ, does anyone with an accurate guage also have a sticker indicating HZ? I wanted to see what the 1800hz corresponded to so I set up a test with a frequency generator and an oscilloscope and took some readings for various indicated rpms. 250 rpm = 106hz 500 rpm = 163hz 750 rpm = 228hz 1000 rpm = 260hz 2000 rpm = 570hz 3000 rpm = 870hz 4000 rpm = 1170hz 5000 rpm = 1435hz 6000 rpm = 1726hz So it looks like the 1800HZ is supposed to represent full needle deflection. Does anyone know what frequency the alternator should produce for a given engine rpm? Sorry for all the questions on what is now an old thread (makes mental note to get off backside quicker in future)