mfi adjustment

[svandamme]

got my lm1 yesterday , got it hooked up , and i was ready to start tuning the engine

removed all the linkage
and started the engine

LM1 immidiately say to rich
used the unisyn to equalize all the cyllinders

unfortunately , the bypass screws were not effective
other than #4 , the screws didn't do anything
wether i closed them up completely
or opened them up , neither lm1 or unisyn registered any difference , bummer
took out all the screws and cleaned them but no luck either

plan 2 , i adjusted all throttle stops, so all 6 cyllinders had almost equal readouts on the unisyn

by the time i finished with that , LM1 gave me an AFR of 15 ish

unfortunately , i didn't have the lm1 on record the whole time because i had to stop start the engine to adjust the throttle stops

small question about the bypass screws :
has anyone come across this before? i think it's carbon in the air channels , is it possible to clean them while the stacks are still on the engine? , i tried Carbclean in the screw holes , didn't work

could i poke in the holes with some wire or a coat hanger ?
does anyone have more detailed pics of the bypass holes??


the rest of the lm1 testing didn't happen yet , because i managed to mangle on of the mfi rods... have to find a replacement before i can continue.. i don't think it's a good idea to do anything with one throttle valve stuck shut

i've also got a little problem with the idle enrichment screw
it seems stuck, won't turn in any direction, the adjuster does move in or out , just won't turn , and is stuck in rich mode, hence the high idle in the lm1 screenshot... anyone seen this? quick fix possibly? i have a large hammer , where should i hit the mfi pumpt to release the idle thingie?

[svandamme]

just received a drawing of the bypass screw bore from a friend,
makes sense now , shouldn't be a problem to clean it out now i know where the bore is :




leaves the idle adjustment beeing stuck
it's rich , so worst case scenario , i'll configure it for a fast idle..(allready blew the budget big style with the rebuild engine , so rebuilding the mfi is not on right now )

[Zeke]

Pipe cleaners and some Berryman's is great for the air screws.

[Jandrews]

Stijn,

Yeah, I have the same issue where adjustment of my air screws makes no difference either way. However, in my case, it is due to my throttle shaft bushings being so worn that they are sucking wind like an old man jogging up hill! You can both see and hear the vibrating throttle shaft in my throttle bodies, and as a result, fine tuning at low/mid range throttle position is almost impossible. At wot, however, it howls like a banshee!!

I'm very intersted in the LM-1 business, and have been keeping an eye on John_Cramer's thread. And if you are going that far to monitor our MFI, seems like it would make sense to put one in each bank.

Anyway, keep us posted on your findings.


JA