Board logo

ms & fueling?..car boggs down
jonesier1 - 19/4/09 at 03:09 PM

Getting nowhere fast.car is starting reasonbly well hot and cold after using a map from someome elses set up(the same as mine) and making a few adjustments to the fuel req.managed to drive it to sva and back..just.As soon as you give it anymore than light throttle it dies away,you can build up speed slowly but loose it on a hill and have to keep changing down .My afr gauge drops to 7.7 ish and i cant get it higher unless its light throttle then its around 10,it  sounds spluttery,nowhere as crisp as it should.Auto tune improves it slightly and i have tried messing about with the ve table but not making any noticeble improvements.or am i barking up the wrong tree.Help appreciated or anyone near plymouth with knowledge !!!!

[Edited on 19/4/09 by jonesier1]


flak monkey - 19/4/09 at 03:12 PM

Yep too rich.

Max power is at 12.5AFR no need to drop any lower than that.


jonesier1 - 19/4/09 at 03:30 PM

So do i adjust my fuel req its at 4.5 at the mo with 2 squirts or the ve or acc enrichment or any adjustment on my gsxr750 t/b's with ford injectors (on a 2litre zetec)???


MkIndy7 - 19/4/09 at 03:32 PM

The ignition map could require retarding at that load point aswell.


brianthemagical - 19/4/09 at 04:21 PM

Req fuel should be set at whatever it is, and then not really need changing. What kind of figures are in the fuel table? What's it like at idle/cruise? What engine is it on? What kind ofpulsewidths is it running? Is the lambda sensor working correctly and what type is it?


jonesier1 - 19/4/09 at 04:37 PM

its a 2.0l zetec on gsxr 750 t/b's and ford inj.ve is around 85 idle and 130 with throttle.it has a wideband lc1.At idle its around 10 as is cruise on my afr gauge.not sure wot the pulse width is off hand.


flak monkey - 19/4/09 at 04:54 PM

Would expect to see VE table figures of about 10-15 for idle up to 130ish for full throttle.

Req fuel I would expect to be aroud 7-11 depending. My pinto on gsxr600 bodies is 11req fuel and idle VE of 14, thats still a bit rich though.

David


MkIndy7 - 19/4/09 at 04:55 PM

An AFR of 10 at idle and cruise? thats way too rich surely I would have thought it would be stinging your eyes if it was that richb (particularly if started up in a garage).

If thats not the case check the Lambda settings, mine said it was wideband in the MS settings yet it was expecting a 5v signal instead of the 2.5v the LC1 provides.


brianthemagical - 19/4/09 at 05:07 PM

First thing to do is set the req fuel correctly, not sure if the mega manual gives instructions, if not i can dig some out for you. My car, 1.9 8v with 38mm ITBs and 240cc injectors is 13ms, but will start and run anywhere between 4 and 20ms.

The ve values sound a bit high for a std head IMHO, maybe 120 max at 100% tps and max torque. Idle should be alot less, maybe between 15-40. the rest of the map should be fairly smooth and WOT should follow the torque curve.

Any chance you can post up your msq and maybe some logs?

By the sound of it you're good at high rpm, it's just low stuff that's at fault? In which case i'd guess the 85 ve at idle. Try making a table, starting with the current one, but put 30 in the bottom left, and the inerpolate up to WOT at max torque, then load that with the engine running. Be sure to log while doing so.

[Edited on 19/4/09 by brianthemagical]


omega 24 v6 - 19/4/09 at 06:22 PM

quote:

An AFR of 10 at idle and cruise? thats way too rich surely I would have thought it would be stinging your eyes if it was that richb (particularly if started up in a garage).



I think flak means a VE table entry of that figure not an afr reading.


jonesier1 - 19/4/09 at 06:36 PM

will double check.all this starts to give you a headache after a while.mite be easier to get it on a rolling road and set up .I knew i was setting myself up for agro when i soldered the thing together.


brianthemagical - 19/4/09 at 07:08 PM

Any chance of the msq, to have a qucik loo at please? It definately sounds like it's overfueling, and more than 12:1 if it's bogging down so much, so your lambda sensor could be right. All a rolling road is going to do is cost you alot of money to fix a problem that sounds pretty clear to me, as i said earlier, a VE of 85 at idle is wrong, and would result in a very rich mixture. If you try and lean it out to something like 30, even if you do it in stages, the worst that will happen is it'll stall, or show a lean AFR.