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01' 5.7L Express got FUEL+Spark=no start


hellah fresh
01-04-2010, 12:12 PM
Ok so as of last week the van did not want to start and so we changed out all 8 new spark plugs and a new ign coil. Now that we have that the van started right up and we let it ran for a good hour half to see if it would die but it didnt. The fuel pressure is good sitting between 50-55psi and the coil have really good spark. Also i forgot to mention the long "L" shape plastic tubing that sits right below the vortech cover has broke off ad so we covered it with duct tape and a clamp. I dont think that should effect the car from starting would it? So now 3 days later the car cranks and no fire but we have good fuel and good spark from the coils. We also checked out the distrubtor cap and it was good. Even tho it started the first time and now it wont start at all... any ideas?

MT-2500
01-05-2010, 09:52 AM
Fuel pressure is not good.
Low enough to give a no start.

Did you recheck for spark when no start?

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.

hellah fresh
01-05-2010, 03:23 PM
Ok i just tested it out today and tried to crank it but wont fire up. So my dad sprayed some carb cleaner into the intake hose and it started right up... so are you suggesting fuel pump?

MT-2500
01-05-2010, 03:34 PM
No just fuel pressure is low may or may not be fuel piump.

Check the fiuel pressure and run test as posted in post 2 and post back pressure readings.
Then we can tell you if fuel pump or other.

hellah fresh
01-12-2010, 10:07 AM
Ok the fuel pump has already been changed out along it the distributor cap + rotors. Like the other guy have posted i think the car have a cold start problem. When it is cold the car will start up fine. But once it warms its hard to start. Also ever since the van didnt throw out any codes as all. Soooo is there like a cold start sensor somewhere or something? The MAF is good.

MT-2500
01-12-2010, 01:37 PM
We need the fuel pressure readings.
Did you check the fuel pressure before and after fuel punmp replaced?
Did you use a good delphi pump or a junk aftermarket fuel pump?

It is not a import with a cold start sensor.

I would also fix the part you taped up in post one also.

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