I finally got my LT8 to run my car. It will start up fine and hold a constant idle and rev appropriately...but I am having some other problems.

1. My idle is way too high...like 1400-1500rpm. I have tried loosening the throttle cable and it is as loose as it needs to be to have the TPS all the way in. I tried adjusting the hard set screw on the TB and I turned it counter clockwise until it was no longer touching the cam...still not any lower. I can raise it by turning it clockwise but not make it go any lower. I checked for any possible vacumn leaks and I can not find any...all the nipples that are not being used are capped off. I am lost as what to do here....the only thing I can think is that my timing is so far advanced that it is raising my idle...is that possible?

2. When I drove my car around, it ran fine under regular conditions, but if I try to acclerate any...not like WOT or anything like that, but just rolling into boost...as soon as it hits about 0psi it acts like it just hit a wall....and I have my Boostcut, revcut, and revlim settings all set to "off". Could this also be timing related? Or are there other settings that would effect this? I am new to MT so I know very little about them and how to tune or adjust them.

3. It smokes alot out the exhaust.....and it stinks to hell of fuel...excessively rich I think. It never used to smoke before, but I did ATF it to get it started, and it smoked alot then of course, but it is still smoking now about 5 hours later when I start the car.

4. Also....my LT8 says MazT and also Ser4 on the startup screen thing....yet I have a Ser5 1990 TII....could that be a problem? or does that have nothing to do with this? I bought this EMS off of another member who also was using it on a Ser5 TII...so I don't quite understand all of that.

Sorry for the long post. Any help would be greatly appreciated.

Thanks,
Scott

 

ok you need to check the timing set the timing lock in screen 31,

check the BAC valve is fully closed, if it is open it will idle higher,

you are just running way to rich you need to do some tuning on it to get rid of the fuel smell, start with the idle settings and then move onto the load settings,

ser4 and ser5 motors are the same, it wont make any difference at all.

Dale

 

make sure there isnt a vaccum leak

 

Your first problem was damn near Identical to mine. I backed off all the screw settings on my TB to zero avail. A redirection of vacuum lines put this at ease. You may want to reevalute your lines, If you haven't already.

 

Yes....Be careful with using the vacuum nipples at the rear of the throttle body. They are actually fresh air lines, and will bypass air past the throttle body if you use them as vacuum sources or redirect them to other vacuum nipples.

 

Huh? They will bypass air past the throttle body? How would they bypass air past the TB when the nipples themselves are past the throttle body on the UIM?

I got the car running fine....she is going in for a tuning on Friday 11-21 to get everything straightened out as far as timing and AFR. The only problem I am having now is the high idle....I can't figure out how to get it to idle down. It is always up near 1500rpm...don't know what it could be. I checked for leaks and could not find any...all my nipples are either being used or are capped off and my BOP kit does not appear to be leaking anywhere around the gasket sealer I put on it...so I don't know what else to check. I also checked the throttle cable and idle adjustment screw like I mentioned earlier...and nothing appears wrong.

 

Take a look at the throttle body again. You will notice how the passages work in conjunction with the black "spacer", to bypass the throttle plates.

 

This isn't Scott, but he's on the dyno right now trying to tune his car, and he is STILL hitting some sort of boost cut...the LT8 is cutting ALL fuel as soon as it sees any boost. They are messing with it right now, But I was hoping someone could give us a little insight to what we should be looking for. RPMloads look good, no boost, rpm or revcut limits are set, they tried setting the boostcut at something, but have yet to run the car again and try it. Everything else SEEMS fine, car runs good, and has great AFR numbers...till the cut.

Dustin.

 

what map sensor are you running?

 

is the MAP sensor line hooked up to proper signal source?

 

The map in the ecu, line from the upper intake man. to the ecu.

 

hmm from what I read the best source is the bottom port of the 3 on the side of the intake manifold facing the ALT

 

His is using the bottom on on that same spot on the S5 turbo manifold.

 

Im going to post your problem on ausrotary
they got alot of MT users there BRB

Ok I posted it

ausrotary.com

under technical


damm that site has slow traffic
must be late over there