Put turbo back together but ran into lots of problems.

First: When I hit the gas the vac starts to decrease like its going into boost but then all of a sudden it spikes to 20 hg vac about 3k rpm and stays there? I never see boost.


Second: my waste gate is leaking into the down pipe even at idle? shouldnt it be completely sealed at idle? (Tial 40mm 5psi spring)If i want to bypass the ACVR until i can fix it i can just hook a vac line to the top port correct? and leave the bottom one uncovered?

Thrird: SFMU static is at 35, and idle when hooked up to vac is at 25 psi, but to achieve this i have to use the bleed screw.
why wont the vacuum screw do anything? i turn it all the way in and out and it dosnt do shit. (2.72 disc silver spring)the bleed screw is the only way i can adjust the FP when its hooked up to Vac. are my settings ok based on my setup?

4th: ACVR is screwing up, possibly wiring, it holds the rpm for some reason and rarely adjusts.

5th: SAFC settings. I dont have a wideband, but its running really rich according to A/F guage. here is my set up, 255 walbro, 38lb injectors, SFMU 2.72 disc. Im currently at 35% reduction at 1k curve down to 5% at 4.5k low throttle. It leaned up a little bit. EGT was reading 900-1000 at idle. should i go to 50%? and how far should i extend the curve? 5k? or is 50% just crazy and somthing else is wrong.

6th: it runs ok now at idle (750rpms) slightly hesitating now and then, but after like 30 seconds it trys to stall compeletly? any ideas?

all guage readings at idle:750 rpms

FP 25
EGT 900
Oil 40
AF: Rich
Vac: 15

Ok after doing some more reading to people use a flat AFC setting all the way across the rpm range or was i right in lowering it a few percent as the rpm increased? ie 1k -35% to about 4.5K -5% or just plain old -35% all the way to 7k in the low.

Oh and I should be using the "KAR" setting right becasue Kar means pressure correct? Im at 6 in and out now im going to try 7.

Originally posted by Jacque766
Oh and I should be using the "KAR" setting right becasue Kar means pressure correct? Im at 6 in and out now im going to try 7.

No

Press is Pressure. karmen is a frequency.

Originally posted by Blizare

Originally posted by Jacque766 Oh and I should be using the "KAR" setting right becasue Kar means pressure correct? Im at 6 in and out now im going to try 7.

No Press is Pressure. karmen is a frequency.

Correct.

Check your STFT with a datalogger to see if you need to pull more fuel at idle. with 450's i pulled 50% right off the top at 1000 rpms on the afc. MY Shoert term fuel trim was almost bang on 0. That means it's not running rich at idle and it also means there is room for adjustment +/- 25 that the ecu can control. Yay. thats the first part to get right. :)



After that, zero it out. Get a wideband before you start pulling lots of fuel to make more power, or you'll blow this engine up.

Ok, so I have learned that the car will not run at -15% fuel curve or higher on the SAFC. It bogs out and stutters. But as soon as i lower it down to -35 to -40% fuel curve it runs great. starts great, idles great, and runs smoothly on the rd.


But the A/F guage reads Lean all the time, even if i lower the fuel curve to -15%. THe only time it goes to optimal or rich is when i slam the gas.

I will have to find more info on how to tune with the A/F guage and no wide band.

EGT's never go over 1200, usually stay between 900-1200.

Pressure is 6 in 7 out. For some reason it just seemed to idle a hell of alot better at 6/7 instead of 6/6 or 7/7. Maybe its my elevation. (4500 above sea level.)

FP always stays aroung 25-30psi at all RPM levels unless i slam the gas, i assume this is normal.

I still can get boost though no matter how hard i hit the gas and race through the rpm range.

how did you guys tune with your a/f guage?

Originally posted by Jacque766
Ok, so I have learned that the car will not run at -15% fuel curve or higher on the SAFC. It bogs out and stutters. But as soon as i lower it down to -35 to -40% fuel curve it runs great. starts great, idles great, and runs smoothly on the rd. But the A/F guage reads Lean all the time, even if i lower the fuel curve to -15%. THe only time it goes to optimal or rich is when i slam the gas. I will have to find more info on how to tune with the A/F guage and no wide band. EGT's never go over 1200, usually stay between 900-1200. Pressure is 6 in 7 out. For some reason it just seemed to idle a hell of alot better at 6/7 instead of 6/6 or 7/7. Maybe its my elevation. (4500 above sea level.) FP always stays aroung 25-30psi at all RPM levels unless i slam the gas, i assume this is normal. I still can get boost though no matter how hard i hit the gas and race through the rpm range. how did you guys tune with your a/f guage?

Unfortunately, I see this phrase as an oxymoron:
"I will have to find more info on how to tune with the A/F guage and no wide band."
It is nearly impossible to tune without a wideband... you don't have to buy one, but you can goto a dyno and have the dyno wideband log your true AFR.