Quote:
Originally Posted by Kalun_D  Accel Gen7 ECU, TWM induction, FAST Edist DIS.
Another specific question, I have a mid range stumble-pop-backfire. It happens between 2,000 and 2,700 rpm. Under light-moderate acceleration. Very light accel or heavy accel and it won't happen. Outside of this rpm range it won't happen. |
I have not played with your system so I cant be specific.
But you have to look at the maps as load vers rpm.
At 2500rpm mid throttle let us say it is at 50% load
At part throttle it is 10%
At full it is 100% load.
It is to lean at 2500 rpm with 50% load.
It is related to the load sites at 2500rpm,it may have 10 load sites at that rpm.
Best way is a dyno.
No accelerator pumps.
Start at the bottom and move up through rpm and load, holding on specific load rpm site to make adjustments.
Ignition you should look for max torque figures if it has a rattle you may have to drop a deg or 2.
Start safe to much fuel and not enough timing is good if you are learning.
I have no idea about your engine but a good engine will want about 30-32 deg max.
You can give it more timing in the lower to mid range rpm with lower loads say 30-50% this will sharpen it up, but you will have to feel that out youself.
Fuel you should be using a meter A/F 14.7s on cruise is ideal full load you will get into the 12s.
These are all ideal readings and eng set ups will change things.
Do accel pumps last on the road by stomping throttle to different deg till you iron out any hesitations.
This is general I hope it helps.
Others will be able to add to this ,good luck.
A handy tool is to get a pair of ear muffs and drill holes in them make a stethiscope using rubber hose.
A copper pipe folded over on one end and drill a hole into the fold.
Bolt this pipe to the head around the intake manifold.
Put the hose from the muffs into the copper pipe.
This will allow you to here it ping.
Test it by putting in timing and get it to rattle so you know what it sounds like.
wear the muffs while tuning it will help.
Jim