Ok I have a problem I can't get my head around. When I am between 900 and 1600 rpm and I smash the gas my car flat spots from what I can tell is that the accellerator pump doesn't operate quickly enough. Now at no load I am running between 13.2 and 13.8 AFR I tried to set it to the map sensor for transitions but it was worse. With it set to TPS is by far best but it could be better. In the accell table I have it set at 500% at the troubled point and it slowly goes up to 800%. I have tried to up the level and lower the level but it looks more like the reaction time between hitting the gas and extra fuel turning up.

Has anyone else had this problem????\


Regards
Michael Smith

 

Hi Michael,
Have you found a remedy yet, if not try working (richen), your map at the higher load values directly above those RPM. Remember the load jumps first and dramaticaly before the revs increase and with one or more of them lean you will not have enough accell to cover it up...
Hope this helps
Gregg

 

Well i did have that on an fd i was tuning up... i ended up advancing ignition on that area and richening it up. Could it be that you are to lean on that area of the load map and the strumble is due to fuel surge when the pump is accelerated? try advancing in that area. it seemed to work for me...i was idling round 20deg....moved up to 28 and was fine. I risked advance in vacuum and low load... a long as you dont get too high egts or excessive oil temp indications! quoting raceing beat.... operating temp of the oil more then 100degc is not healthy.

George

 

Thanks for that I will have a go some day this week. People with manuals can get away with this with a rev and dump (My Favorite) but because I have a auto with a stall converter I can't do the rev and dump. I stall to 2700 and am just making boost. but if I am crusing out my driveway and have to thump it because of a oncoming car it coughs and then after more gas lights up both tyres. This is not good if the other car is a police car!!!

Thanks again Gregg and George.


Cheers
Michael Smith

 

Hi Michael,
Well you are not alone in the automatic world, my daily driver is an 88 fc auto with several internal trans mods and a wolf 3.1. I kept the stock converter as I need economy more than the launch, but it is nice to smoke the tires going into high gear...

Gregg

 

OK some more advance made it a lot better I also found that it is flooding the engine and a the accellerator pump was dumping 16ms worth of fuel+ 5ms at 36% load and 1000 rpm a little much!!!! Thanks guys

Michael Smith

 

Fixed up the accellerator pump and took it back to 4-6 ms and it goes like stink better get some new rubber!!!

Michael Smith