So i installed a different ecm and converted to a heated o2 sensors a couple weekend ago.

well upon installing the ecm i imidiatly noticed my idle was at 1000 where at the old ecm had it at like 700-800.

so i hooked up a scan tool and my o2 sensor was working great it was actually switching at idle now

but my blms were at 108

soon after i ajusted my min air rate and tps

well low and behold the car was idling through the iac only haha so oviously something was deffinatly wrong with my old ecm becuase i had ajusted min air and tps when i had the old ecm in and got it to idle specs.(which happened to have the tb plates closed completally.

so any ways after ajusting min air rate and tps my blms were 115-120 rance at idle now.

so deffinatly better but still a tad rich.

does anyone here think my bosch type 3 injectors 22# could be causing it to be slightly rich(low in blm's)

or what else can i look for?

what about the 180*t stat thats installed and royal purple coolant addative im running about 180*-190* could this richen the mixture a little?

i also have headers to full exhaust deleted smog/air, a/c, egr, holly afpr, air foil, k&N thats about it for motor performance.

any advise, comments, and this would be helpful

thanks!

 

Fuel pressure could be too high. What did you set your AFPR at? Bosch design III injectors are flow tested at stock fuel pressure. Higher pressure will make them dump more fuel. Is the new computer running the stock program?
Have you done any other mods to the engine, such as an aftermarket cam?

 

i agree, at idle you should have 40psi FP with the vac hose on a lot of guys set the reg with the hose off. Do not do that because the injectors will jump to like 23.5 lbs and the new o2 will start adjusting off idle mixture.causing blm to be low.. the low number means that its taking fuel out, its still not rich after the ecu reads this..But at idle in open loop it will be way rich, but, only till the loop closes. sometimes those o2 sensors will just react too much.. that orig ecm is not that sofisticated.. Also make sure the constant is set to the injector size

 

If you have not altered the tuning in the chip you will have a host of problems that will contribute to the car running rich.

EGR and air pump need to be disabled in the chip.

If you change the thermostat it needs to be accounted for in the programing. The temp tables change the enrichment based on temperature

Fuel pressure needs to be correct at 45 psi wide open

if your adjusting the throttle blades you need to check you TPS sensor to make sure it is still bellow .5 volts

 

fuel pressure is 46psi wot(vac unplugged. 38-40 with vac.) stock computer. no cam no internal mods and only the externals that ive listed above.

and as far as tunning goes i havent not gotten the equiptment to tune yet. so im sure that could be why my blm's are low.

and tps was ajusted last to .54v so its dead on. at idle over 4.2v wot

i guess the answer is in the tunning. time to buckle down and get tunning equiptment amongst other things i need for this car lol...

thanks for the replys.

 

thats it, you cannot up the injector size without upping the constant... the computer has to know what injector it is firing,, go get a tune

 

injectors arnt larger. they are same flow rate as stock just newer and more efficent

 

sorry thought you had a 305 for some reason, is the new ecu for a 305 or 5.7 make sure you replaced it with the right one. otherwise look for a slight vac leak, or try lowering FP by 3psi.. sometimes the guages are not accurate 100%.. you are only off a little

 

new ecu is deffinatly for a 350 and prom is aswell.

i dropped fuel psi with no change in blms what soever.

and vac leak would make blms go high.

thanks!

 

yea you are right... drinking again.. blms would go like to 150 with a vac leak

 

yessir. thanks for the help tho is is apriciated!

 

If you deleted the air pump and EGR without disabling it in the chip, this will cause some of the problems you speak of.

 

i think the biggest problem or the one that really bugs me the most is the rough idle.

every part is working on the car everything is tunned and where it needs to be and it shakes at idle and motor mounts are good and they are the rubber ones. like a random missfire at idle.

canthe items thath aveb een done to or take off my car have any effect on my idle trough the chip. a/c oviously not, egr isnot active at idle, smog/air pump and system? maybe not really sure.

and stock pound injectors, upgraded ignition, full exhaust including headers.

i wouldnt think haveing any effect on the idle.

but im not 100% sure thats why i ask

i guess im looking for a more detailed (this this and this are causing your rough idle and/or rich blms.)

or could be contributing to.

thanks.

 

with everything new and working by chance do you possiblly have a intake valve adjusted too tight that it is hanging open. if it is i think will cause rough idle, plus as a bonus you will have low blm #due to the dead cyl. did you do a compression test

 

i did a compression test a while back and i had 150 even across the 8

but i have ajusted the valves since then.

engine running and hot. losen untill it chatters slowly tighten untill you get 0 lash or chtter is gone. then 1/4 turn more.
is this the correct procedure?

ill proably do it again today just to make sure ive heard everything from 1/4 turn to 1 full turn after chatter is gone their is no real set directions it seems.

and my vacuum is at 22hg idle dead steady. so valves seem to be alright. according to vacuum.

 

DO THEM COLD 1 AT A TIME. TURN THE ENGINE OVER TILL 1 VALVE IS COMPLETLY OPEN THEN ADJUST THE VALVE NEXT TO IT 0 LASH PLUS 1/4 TURN. IF YOU WANT TO EVEN ADJUST THE VALVES. I THINK ITS WORTH A SHOT.

 

see ive heard both cold and off and then like i have done it hot and running.

but i supose i can try it off and see what happens any difference really?