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no start


trapezoid
12-19-2008, 03:51 PM
2001 blazer no start. Will start with starting fluid. Good spark, good fuel pressure, good crank. Not sure whats next. TPS, Map and cts good. Got the reader no codes. :banghead: Please help, what could I check next. Have already checked the alarm system. Injectors sound like they are firing.

dr_lee29
12-19-2008, 04:06 PM
If it starts with starter fluid, that suggests the problem is the fuel or fuel delivery.

trapezoid
12-19-2008, 04:23 PM
checking that now. Will get back to you. Thank you

MT-2500
12-19-2008, 04:30 PM
Start with a fuel pressure check.
Post back fuel pressure readings.

trapezoid
12-19-2008, 05:41 PM
Fuel pressure with key in run position is 58 at the schrader valve. According to the haynes manual it is good between 58-61.

MT-2500
12-20-2008, 08:47 AM
Fuel pressure with key in run position is 58 at the schrader valve. According to the haynes manual it is good between 58-61.

Mr Haynes lies a lot.:lol2: :rofl:

4.3 specs are 60/66
What engine do you have?
If a 4.3 V6
You need 64-65 key on prime up or engine cranking to squirt injectors cold.

Also unless you want to blow the dip stick threw the hood only use carb cleaner as a starting aid.

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 and fuel pressure testing guide line.
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.

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