Re: Hentai's 1992 Mazda Miata (15th)
Posted: Wed Dec 09, 2015 11:31 pm
Paste:
(11:20:03) Fred: ok, well, if there is a 2v drop across the 1k resistor then you have a 1.5k in the pull down where you should have 100k
(11:20:51) Fred: which could mean they don't turn on reliably
(11:21:11) Fred: so that's the first thing you should check and change
(11:21:25) Fred: and you may want to roll your dwell back at the same time, as they'll fully saturate with 12v applied
(11:22:03) Hentai: if I run my dwell back from 4.8 to 4 I get more noticeable missfires
(11:22:04) Fred: R103 R102 by the looks, make sure these are 100k not 1.5k
(11:22:09) Fred: well yeah...
(11:22:18) Fred: if those numbers are correct,, you're lucky it works at all
(11:22:33) Hentai: haha
(11:23:03) Hentai: so r104 and r105
(11:23:06) Hentai: 100k
(11:23:22) Fred: basically the input of the fet driver is super high impedance and presents almost no load to the cpu at all
(11:23:30) Fred: so seeing 2v across your 1k drive resistors is bad
(11:23:35) Fred: no no
(11:23:41) Fred: 104 and 105 should be 1k
(11:23:42) Fred: check that too
(11:23:43) Hentai: ok
(11:23:49) Fred: they could be 66k if the others are already 100k
(11:23:52) Fred: check all four
(11:24:28) Hentai: I will verify them all on the circuit paths
(11:24:30) Fred: once you have a solid 5v at the input of the driver, you will get a solid nominal 12v at the output assuming a good 12v feed
(11:25:02) Fred: if you still don't have 12v at the inner end of r100 and r101 then the feed is bad
(11:25:07) Fred: or the jumper wrong
(11:25:09) Fred: or no jumper
(11:25:30) Fred: do you have the link in the circle?
(11:25:38) Fred: and is it to the 12v side?
(11:25:50) Hentai: yeah 12v jumped
(11:25:57) Hentai: but I could accuratly check it at the time
(11:25:57) Fred: ok
(11:20:03) Fred: ok, well, if there is a 2v drop across the 1k resistor then you have a 1.5k in the pull down where you should have 100k
(11:20:51) Fred: which could mean they don't turn on reliably
(11:21:11) Fred: so that's the first thing you should check and change
(11:21:25) Fred: and you may want to roll your dwell back at the same time, as they'll fully saturate with 12v applied
(11:22:03) Hentai: if I run my dwell back from 4.8 to 4 I get more noticeable missfires
(11:22:04) Fred: R103 R102 by the looks, make sure these are 100k not 1.5k
(11:22:09) Fred: well yeah...
(11:22:18) Fred: if those numbers are correct,, you're lucky it works at all
(11:22:33) Hentai: haha
(11:23:03) Hentai: so r104 and r105
(11:23:06) Hentai: 100k
(11:23:22) Fred: basically the input of the fet driver is super high impedance and presents almost no load to the cpu at all
(11:23:30) Fred: so seeing 2v across your 1k drive resistors is bad
(11:23:35) Fred: no no
(11:23:41) Fred: 104 and 105 should be 1k
(11:23:42) Fred: check that too
(11:23:43) Hentai: ok
(11:23:49) Fred: they could be 66k if the others are already 100k
(11:23:52) Fred: check all four
(11:24:28) Hentai: I will verify them all on the circuit paths
(11:24:30) Fred: once you have a solid 5v at the input of the driver, you will get a solid nominal 12v at the output assuming a good 12v feed
(11:25:02) Fred: if you still don't have 12v at the inner end of r100 and r101 then the feed is bad
(11:25:07) Fred: or the jumper wrong
(11:25:09) Fred: or no jumper
(11:25:30) Fred: do you have the link in the circle?
(11:25:38) Fred: and is it to the 12v side?
(11:25:50) Hentai: yeah 12v jumped
(11:25:57) Hentai: but I could accuratly check it at the time
(11:25:57) Fred: ok