96 blazer problems!

[96blazerlt4x4]

we have a 96 blazer lt 4x4 4.3l highoutput

the truck is having problems with starting up...it sometimes starts..and sometime doesnt..

ive been told to replace my fuel filter..and i did that..still having problems...ive been told my fuelpump is bad....could that be?

my OBD port doesnt read anymore either...ive tried hooking up to a reader with no success..

the fuelpump will not come on for days..then suddenly it will...is the reLAY bad? where is the relay?

[joeuser742]

Hmm, with my other car, I had a problem with the Scanner tool not reading/powering up, I found a blown fuse. Other than that, not sure....bad connection somewhere, bad computer, bad ground, ....

[Jeremy-WI]

Does your cigarette lighter work, on the trucks the same fuse powers the cig lighter as the OBD port. I think the fuel pump relay is behind a panel in the glove box

[MT-2500]

Does the yellow check engine light come on key on at start up?

For the hard to start part try this.
Hard to start cold.
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.
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.
Post back fuel pressure readings.

MT

[96blazerlt4x4]

Originally Posted by Jeremy-WI

Does your cigarette lighter work, on the trucks the same fuse powers the cig lighter as the OBD port. I think the fuel pump relay is behind a panel in the glove box

which relay is it..the L or R?

[96blazerlt4x4]

Originally Posted by MT-2500

Does the yellow check engine light come on key on at start up?

For the hard to start part try this.
Hard to start cold.
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.
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.
Post back fuel pressure readings.

MT

my check engine light has been on for daaaaaaaaaaaaays....

im pretty sure my fuelpressure is fine...but i will check

[MT-2500]

Originally Posted by 96blazerlt4x4

my check engine light has been on for daaaaaaaaaaaaays....

im pretty sure my fuelpressure is fine...but i will check

If the check engine light is on it has beeb trying to tell you something.
Check them codes and post back code no.

The ony way to know if the fuel pressure is good is to put a fuel pressure gauge on it.
MT

[96blazerlt4x4]

Originally Posted by MT-2500

If the check engine light is on it has beeb trying to tell you something.
Check them codes and post back code no.

The ony way to know if the fuel pressure is good is to put a fuel pressure gauge on it.
MT

thats the problem..i cannot check the codes..my obd port wont read! its like the port is fried or something

[MT-2500]

http://www.troublecodes.net/OBD2/

See if it has 12 volt power on the plug.
MT

[96blazerlt4x4]

are there any online manuals for the 96 blazer?

[MT-2500]

Yes
It will cost you 24.95$ a year and take 10 minutes to get it.
But well worth it.
http://www.alldata.com/products/diy/index.html
MT

[96blazerlt4x4]

how do i test my fuelpump?????
we dont hear the "prime" when turning to the "ON" position

[Rick1488]

Originally Posted by MT-2500

If the check engine light is on it has beeb trying to tell you something.
Check them codes and post back code no.

The ony way to know if the fuel pressure is good is to put a fuel pressure gauge on it.
MT

My check engine light never beeped when it came on.. 96 Blazer

[Rick1488]

Originally Posted by 96blazerlt4x4

thats the problem..i cannot check the codes..my obd port wont read! its like the port is fried or something

I had the same problem 3 months with my port I had a partial blown computer... I bet so do you... The computer isn't fully wasted so it still controls the engine.

[96blazerlt4x4]

Originally Posted by Rick1488

I had the same problem 3 months with my port I had a partial blown computer... I bet so do you... The computer isn't fully wasted so it still controls the engine.

did you geta new computer?

we were told by chevy the computer was about to "go" about 6m ago...