1996 Silverado problem

[stryped]

I currently have no code. However I took data on my scanner twice. The truck sputtered and ran a little rough as soon as I left the driveway. It seem though the further I went it started to get better. Truck has had a catylist system efficiency below threshold for a number of months. I assumed it was a catalytic converter and would not be related. Truck has 342,000 miles. New plugs, wires, cap and rotor in April. Today I replaced Ignition control module and ignition coil. Ensured continuity with battery ground on the ICM harness. Ensured continuity on the white wire from computer to ICM.

 

Problem started as what felt like "slipping" several weeks ago when leaving for work. Did not seem to be getting as many miles pertank either.) Never had that problem again for the rest of the day. This lasted for a few weeks. I put two bottles of fuel injection cleaner in tank and filled up tank. A few days later went out to start and took forever to start. Once did ran rough. Got the code P1351. Did above diagostics. Getting 6 colts to the ICM harness. (calls for 1-4 in book). Checked crank sensor. It is supposed to output "approximately" 5 volts but is outputting 4. Cleaned with a wire brush chasis ground. Code has not come back yet but I have not driven truck other than to do the data test a few minutes ago. (And still seem to be exhibiting problems). All sensors have he reguired supply voltage).

 

On a whim I checked fuel pressure. It was within specs at 64 psi. (Calls for 60-65). However, when turning the key off the pressure drops down a great deal. In 5 minutes it dropped 30 psi. I think my Haynes manual says this is abnormal but not sure.

 

is the truck safe to drive to work? It seems to get better as it warms up but I dont want to get stranded. It is my daily driver and I dont know what to do.

 

Here is the data I downloaded:

 

 

Location #1 (Test 1)

 

DTC-cnt 0

 

Fuel Sys 1 OL

 

Fuel Sys 2 OL

 

Load_PCT(%) 4.7

 

ETC (F) 108

 

Shrt Ft1 (%) -3.1

 

LongFt1(%) 0.0

 

Shrt FT2 (%) -3.9

 

LongFT2 (%) 0.0

 

MAP (in HG) 11.5

 

RPM (/min) 668

 

VSS (MPH) 0

 

Spark ADVC -19

 

IAT (F) 70

 

MAF (1b/min) 1.198

 

TP (%) 0.0

 

02sB1S12—B2S12—

 

O2B1S2 (v) 0.230

 

SHRTFTB1S1 (%) -3.9

 

O2B1S2 (v) 0.340

 

O2B2S1 (V) 0.130

 

SHRT FT B2S1 (%) -5.5

 

O2B2S2 (v) 0.070

 

OBD OBD2

 

Location #2 (Test 2)

 

DTC-cnt 0

 

Fuel Sys 1 CL

 

Fuel Sys 2 CL

 

Load_PCT(%) 17.6

 

ETC (F) 205

 

Shrt Ft1 (%) 1.6

 

LongFt1(%) 0.0

 

Shrt FT2 (%) 1.6

 

LongFT2 (%) 0.0

 

MAP (in HG) 26.6

 

RPM (/min) 1505

 

VSS (MPH) 41

 

Spark ADVC -15

 

IAT (F) 70

 

MAF (1b/min) 8.279

 

TP (%) 42.4

 

02sB1S12—B2S12—

 

O2B1S2 (v) 0.100

 

SHRTFTB1S1 (%) 3.9

 

O2B1S2 (v) 0.670

 

O2B2S1 (V) 0.110

 

SHRT FT B2S1 (%) 3.1

 

O2B2S2 (v) 0.800

 

OBD OBD2