The car will run on dizzie power no problem, used this to check the coils are firing in the right order at the right time ( marked the crank at 90 deg intervals )
switch over to coil packs and it coughs and splutters and backfires. about 8 deg adv being shown on the advance gauge.
I there anything else that I need to start looking at missing or gudes to reed.
many thanks
Agriv8
Have you got enough dwell time set for your coilpacks?
Have you tried advancing the ignition more? (where does it run using the dizzy)
Mine is happy to idle with 10 to 12 degrees of advance. It's not keen on anything less.
Quote from: cliffb75 on April 14, 2007, 09:12:46 PM
Have you got enough dwell time set for your coilpacks?
Have you tried advancing the ignition more? (where does it run using the dizzy)
Thanks cliff
Dwell angle havn't touched that on the vems. looking at the spark its there and its blue but gut feeling it seems week, I will compare that to a spark given of the dizzie.
Re the dizzie thought that while going for a walk with the wife this eve. ie time it back the other way ( find out what advance when ticking over on the dizzie ) replacte that with the coil packs/vems.
Thanks
Agriv8
Quote from: dnb on April 14, 2007, 10:33:32 PM
Mine is happy to idle with 10 to 12 degrees of advance. It's not keen on anything less.
Intresting not gone as far as that will dail a bit more in tomorow.
I have been playing with your maps today while running under dizzie power. It was running rich as expected so running req fuel 11 and used you map and used the shift function seems about happy after shifting it to -15 ( it stopped stinging my eyes !!! ) at which point was getting reasnoble Air fuel ratio ( aiming for 14 - 15 to 1 ) and a stablish lambda. Do you know what fuel presure you run ( i am about 36 - 38 PSI - batch fire )
Thanks
Agriv8
My fuel pressure was 3.5 bar with the vac disconnected from the pressure reg. It's a crappy FSE regulator, so is something like a 1.7:1 ratio rising rate (which is nasty for idling on big injectors, but good for the small ones). My injectors are sequential.
I am using a dwell of about 3ms (I think - would have to check the config). I found this gave nice fat sparks with my coils. Your coils will probably prefer something different, but this isn't surprising!
I found the auto VE learn feature to be pretty useful. The settings for it in the config I sent you shouldn't be too far out for you. All you need to do is switch it on and let the car learn the fuelling by itself. I think you have to manually merge the original map and the learned map using a keyboard command, but I don't remember what it is.
Checked my dwell last night and its set to 2.65 can I safly increse this a little ( this should give me a bigger spark ?)
If my assumption is right this is how long the vems unit is going to chage the coil pack up before cutting the earth the resulting charged energy has no where to go but down the plug leads resulting in a spark. I belive I am looking for a nice blue fatish spark ( I have what I would consider a thin blue spark at the moment ) I there a way I can check that I havent gone too far ?
dnb what plugs are you running ? running NGK copper in mine been ok under dizzie power maybe the coil pack system requires diferent ? what gap are you running ?
I too am running a FSE ( disconected on the Vacume as vems will be able to a better job of giving more fuel when required)
Hope to have a play tonight both Dwell and tickover advance as both my neigbors were out barbecuing / enjoying the sun yesterday and though I enjoy the v8 bable / bark I suspect that it could get a bit wearing as it interupts our normally quiet sedate neigbourhood ;D ;D
kind regards agriv8
One of my neigbours used to live near Bristol Avenue. He's therefore used to the things I get up to...
I'm running the standard plugs with the standard gap. They were never a problem.
I'd try increasing the dwell by a very small amount to start with. You only need "just enough" spark energy. You're right with how it works.
Managed to get her running a vidio clip taken on my camera it Sound like it is knocking ot t1t's off trust me its not ( though those rhodes lifters are noisey) will pull her outside and try again soon. dnb yup 11 deg of adv and she is happy ( thanks :) :) :) :) )
anyway here is proof with the dizzie off ;D
http://s167.photobucket.com/albums/u157/Agriv8/?action=view¤t=Full.flv (http://s167.photobucket.com/albums/u157/Agriv8/?action=view¤t=Full.flv)
Anyway best get reading the tunning guide.
Regards
Agriv8
Excellent news! Now there's a few of us with RV8s running on VEMS, we're going to have to have some get together :)
We could get sponsered by Esso Mine cant pass one !!!!!.
regards
Agriv8
It will. Mine does 30 MPG on the M-way since VEMS.
30 mpg :o :o :o :o thats possibly somthing to look forward to !!! no whear near that under the hotwire setup
Anyway taken her down to the filling station under her own power tonight and a couple of tripps round the block. need to read up on the auto tune facility as thats the next job after i have swapped an injector out. ( no 8 :-[ :-[ ) as that particular exaust primary was a lot cooler than the others getting a spark to it and there was no exhaust popping ( so no unburnt fuel ) will double check continuity before.
The tickover was steady as a rock ( even when sticking a all the big voltage pulls main beam / fan ).
Also need to look at warmup enrichments and aceleration enrichments.
Anyone fancy taking a look at some logs for me ? Poss friday / the weekend.
anyway off to bed one very happy camper.
All the best agriv8
Post the datalogs here and we can all sniff over them :)
Happy to have a look :)
couldnt work out how to post a file so emailed my log to ROb and dnb
thanks
Agriv8
Looks frightenigly lean to me 1.1 to 1.2 all the time!
Richen it up by increasing Req_fuel but a milisecond or so.
Agree - It's very lean. Increase the reqfuel with the aim of making it rich. Then set the lambda correction to allow it to lean the mixture out to the target. (Lambda control in VEMS works best this way)
thanks chaps, will double check lambda calibrations agian ( as I have been swapping maps and generally pratting about ) if Lambda still calibrated Ill richener her up a little. and then let vems lean her up from watching the Lambda
My only worry is that if I richen her up that will mean more backfiring ? ( possibly running so lean that there isnt enough fuel for the spark to get hold maybe ) it already sounds like a rally car where they dump fuel down the exhausts to keep the tubo spooled up.
will try and play more tomorow but having further laptop trouble.
Thanks once again
Agriv8
You have perfect lambda on idle, it just seems that your fuel map is too lean everywhere else.
Do you have the 30v transient voltage suppression diode in your flyback line? If you haven't then you'll find that doing so will really help flatten out your VE table with the Speed Density fueling.
Don't forget, lean mixtures burn slowly, when you are too lean on start-up you get back fires as the mix is still burning when the inlet valve opens and ignites the incoming charge.
Rob
No Diode fitted ( maplin dont appear to sell them unless they call them somthing diferent ).
regards
Agriv8
You're right - I couldn't find them on Maplin's website either.
The transient diode was the best tuning I did to the TVR. Suddenly the fuelling became sensible.
I have a few knocking about at home. Fire me an email and I'll dig one out.
No email = me not remembering :)
Quote from: Agriv8 on April 22, 2007, 11:50:09 PM
My only worry is that if I richen her up that will mean more backfiring ? ( possibly running so lean that there isnt enough fuel for the spark to get hold maybe ) it already sounds like a rally car where they dump fuel down the exhausts to keep the tubo spooled up.
Agriv8
By the sound of it, in your case its being lean thats causing the backfiring - as you say its not igniting properly in the chamber, so it ends up getting burned in the exhasut.
Anti-lag is not the same at all, plus there is the influence of rev limiters in the sounds you see on TV.
Have you got the closed loop turned on eveywhere? if it is on, and you are still 20% lean you need to ad A LOT of fuel to the base value...........
If you're using anything based on my base map, then it will never richen the mixture by more than 5% or 10% (IIRC) this is to stop run-away richening the mixture on misfires. Again, if the map is based on mine then lambda correction operates all the time except beyond 90% throttle.
As Cliff says - add a LOT of fuel, as my settings will let the correction lean things out by at least 20%
Was half way typing a response when you posted that up ( it would explain why the fuelling is so far out ).
suspect that My settings are not allowing the lambda to lean thing off ( or not lean it off enough anway ) where do i start looking for these setting then.
Regards
Agriv8
You want to richen it up, lean it off any more and you'll be running on fresh air!
before you use the EGO sticking plaster get more fuel in.
Quote from: Agriv8 on April 23, 2007, 02:53:45 PM
suspect that My settings are not allowing the lambda to lean thing off ( or not lean it off enough anway ) where do i start looking for these setting then
You're already running VERY lean, so there's probably nothing wrong with the EGO (wideband) settings at all. You just have Req_fuel far too small.
As Rob says, any leaner and there won't be any petrol in there!