1996 Chevy Express 3500 Won't Start

[danny1977]

My Express Van 3500 will Not start. It cranks but will not start at all. Last time I started it was blowing bluish smoke out the exhaust. then the next morning would not start. It has been very cold outside. Could it be Fuel filter? someone told me. Today I tried to start again and it backfired and black liquid came out exhuast. Please Help. Don't know where to start

[MT-2500]

How much blue smoke?
How many miles and what engine?
Has it been using oil or coolant?

When no start check for lose of fuel pressure or spark to all plugs.
What is the fuel pressure key on and on cranking engine?
Got spark to all plugs.

[danny1977]

Originally Posted by MT-2500

How much blue smoke?
How many miles and what engine?
Has it been using oil or coolant?

When no start check for lose of fuel pressure or spark to all plugs.
What is the fuel pressure key on and on cranking engine?
Got spark to all plugs.

The Blue smoke lasted about 15 minutes of running.
150k miles
Coolant i refill quite often. I do have a small leak on head gasket.
I dont know how to check Fuel pressure sorry

[danny1977]

The Blue smoke lasted about 15 minutes of running.
150k miles
Coolant i refill quite often. I do have a small leak on head gasket.
I dont know how to check Fuel pressure sorry

[MT-2500]

Originally Posted by danny1977

The Blue smoke lasted about 15 minutes of running.
150k miles
Coolant i refill quite often. I do have a small leak on head gasket.
I dont know how to check Fuel pressure sorry

Got spark to all plugs?
Can you hear fuel pump run key on prime up or engine cranking?
You check fuel pressure with a fuel pressure gauge on the fuel pressure test port?

On head gasket you need to get it running first and then test for head gasket leakage.

Was it a lot of blue or white smoke?
Blue or white?
Can you smell coolant at tail pipe?

[danny1977]

Yes i got Spark to all.
I do hear the fuel pump come on.
yes there was a lot of blue smoke
no i don't smell coolant at the tailpipe

[MT-2500]

Originally Posted by danny1977

Yes i got Spark to all.
I do hear the fuel pump come on.
yes there was a lot of blue smoke
no i don't smell coolant at the tailpipe

Check your fuel pressure.

Post back fuel pressure radings.

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.