93 LT1 Wont stay running
 

Hi
1993 LT1 has new fuel pump, pressure is 45 when cranking and 38 when it ran last ,i removed the injectors and cleaned them, with compressed air and carb clean,i checked the ohms and i get a reading of 13.5 ,noid light pulsates when cranking,on all , no codes with snap on 2500 scanner, good spark, the car starts for 1 to 4 seconds and stalls ,
Thanks in advance
Uwe

RE: 93 LT1 Wont stay running
 

Now I have no spark and no noid light ,

RE: 93 LT1 Wont stay running
 

Usually, no spark and no injector pulse at start up means no crank sensor. ECM looks at crank signal to find #1 for timing and then uses cam sensor for fine tuning injector pulse.

RE: 93 LT1 Wont stay running
 

Where is the crank sensor on the LT1?
Thanx Uwe

RE: 93 LT1 Wont stay running
 

In the Optispark distributor behind the water pump. Not something that is easily replaced.:)

RE: 93 LT1 Wont stay running
 

mech259
Thank you for the heads up, does anybody have a wireing diagram posted on this forum ? with out haveing to buy shop manual?
Thanx Uwe

RE: 93 LT1 Wont stay running
 

I would do some diagnostics before replacing anything. Make sure the sensors are putting out a signal. Don't have the wiring diagram, but if you can access crank and cam outputs with an ac voltmeter to see if you have cranking voltage, that will tell you that they are present and accounted for. Might need to have someone with proper equipment to check the outputs and if they have a scanner, check the serial data and see if it shows cranking rpm on scan tool. Early LT1's had problems venting rust and moisture from the distributor cap and they updated the cap and it has a vent on it now.[8D]

RE: 93 LT1 Wont stay running
 

1 Thanx for your replie
1 I hooked up my snapon 2500 scanner and found no cranking volts .
2 I ordered a Distributer cap ,rotor,=(The whole kit)Can i use MSD Kit? and Delco wires, along with a water pump,and gasket,
3 the cap looks like it was never changed (128K)on it and some after market wires are on it
4 Itried disconect on battery , and wrap the ecm (gently) its a reman AC Delco
cant wait to getter goin
Thanx Uwe
I WILL KEEP YOU ALL POSTED

RE: 93 LT1 Wont stay running
 

Does your MT2500 show any rpm while cranking? If not, probably the crank sensor is bad if it has supply voltage to it. If I am not mistaken, it is a combination sensor (cam, crank, maybe TDC). Good Luck. [8D]

RE: 93 LT1 Wont stay running
 

I hooked up the scanner and i get 16 low resolution pulse failer.,no spark,no noid light
Thanx Uwe