A buddy of mine is working on an 95 LT1. He just freshend the motor due to a rod-knock. After the new motor, it won't run w/ the MAF plugged in. It ran fine before and it runs fine w/o the MAF(should be in LIMP). He's checked all grounds, and checked to make sure he didn't pinch any wires. It's not throwing any codes on a Snap-On scanner. w/ the MAF plugged in it fire and die, but thats all. He said he can start it, un-plugged, and it will run fine, but if he plugs the MAF in it'll die within seconds. I don't know to much about the LT1.

...any ideas?

 

also, vac is around 30hg, timing has been checked,(even tore down to opti-crap and re-set/checked dist) and fuel pressure is good. He said maf wires have the 12-volt, gnd, and 5-volt. what gives???

 

try swapping the MAF with one from another LT1, if you can.

 

tried a new one today, same results....

 

could it be the TPS setting? maybe cfm(maf) reading is high compared to TPS reading and the computer is outta whack? - it wasn't changed, but we're at a loss. I don't know enough about the LT1.

 

nevermind

 

tps voltage is in spec w/ the book.

anyone???

 

check out your map sensor, and really look at the map sensor connector...

 

Also check out the IAT sensor

http://shbox.com/1/harness.htm

 

My money is on the wires going to the MAF plug. I had one once with the exact same symptoms. Turned out that one of the wires was broken right at the MAF plug, you couldnt see it unless you were specifically looking for it. IIRC, it was broken inside the coating too so it didn't look broken. I had to remove the pins from the plug, resolder the wires, and reinstall into the plug.

Also, runnung without the MAF connected will not put it in limp mode, it just runs as a speed density system(like the TPI and '92-'93 LT1 motors). You might get an off idle stumble and will have worse gas milage, but it will still be perfectly drivable. If your going to have your PCM flashed anyway, you could have it converted to a full time speed density system.

 

thanks for the responses. I'll be over at his place tonight, so we'll try that and I'll post back tomorrow.
- is a 92 TPI Map the same???I've got one I could try...

 

...I guess somtimes it just takes a fresh set of eyes. - He had forgot the silencer tube off the bottom of the inlet elbow.

Thanks for all the help.