okay here's what I got that might have somthing to do with my problem.

381 cu in, ported heads, Hot cam, 1.6 rr, knock module, 3500 stall converter
used tunercat, changed cylinder volume, no other tuneing done.

Engine starts and idles great, block learns around 121

If i'm driving and come to a stopsign, the engine will die. It also has problems if i'm going down hill with foot off the gas, 20-25 mph or so, will try to die.
is the pcm cutting fuel on the decel and the stall making it drop too much? I thought it would kick the fuel back in if the rpm dropped too low.

when the engine dies at the stop sign, i can start it back up and it idles just fine .

any ideas to try right off??? is there a place in tunercat to disable decel fuel cut?

 

I had a stalling problem also, and I thought that it was the IAC. When I would let off the gas and brake, the engine RPM would dive and stall. I noticed during logging the IAC would be steady at about 60 counts, and when a lifted on the gas it would quickly rise to stop the engine from stalling, but could not go high enough to prevent the stall. So, I drilled a small hole in the TB. I now have the engine idleing at 800RPM with the IAC count at 10. Now there is more room for the IAC to spool out and prevent the engine from stalling.

 

what size hole did you drill, was this LT1 or ls1...

I could crack the throttle blades open at closed throttle ouldn't I?

 

crack open throttle blades then readjust your tp voltage. i belive to .65 my 383 idles 950-1000rpm.

 

Do you hve the VSS hooked up. Is it calibrated to the proper gear ratio and tire size? These will affect IAC and idle down.

Steve

 

no vss sensor, TH400 trans..am i going to have to fool the pcm???

here's a datalog ,

http://www.lt1swap.com/brendanlt1.uni

IAC counts 65 to 70 at IDLE when warmed up.

after a short drive, coming to a stop, the IAC takes a dive to zero, then hangs around 10 to 15 when i'm keeping it running with two feet, one gas, one brake.

look at Rec # 3500 to 3600 on the datalog, everything before 3500 IAC around 60s-70s after 3600 nothing over 25 counts.

if i let it die, and restart it, it idles fine..iac 65 to 70

what do you all think?

 

Your problem is part of the reason VSS is fed to the PCM. I had same problem when my VSS was way off in gear ratio calibration. Get a TH400 VSS from "Jags that Run" and It'll help. JMHO


Steve

 

okay i've done some reading, the 95 has a 40 tooth reluctor ring and a VR sensor correct?

 

Are you running a M6 binary file or an Auto??

Steve

 

manual transmission bin.

 

Your M6 bin is expecting 17 pulses per output shaft revolution. Do a search and you'll find there's a lot of people that have hooked up a VSS on TH400.

Steve

 

If you cant get the VSS hooked up then drilling a hole in the TB does work. You dont actually make a new hole but simply enlarge the existing one in the TB. Take a look at the center of the TB from the front side. Just below center is a hole which bypasses the IAC motor but still feeds air to the IAC passages... making it larger allows more air through which should prevent the stalling problem. This does only apply if its a stock TB though.