1999 Suburban hard to crank in the morning.
rondupree1212
07-22-2009, 08:38 AM
1999 Suburban is hard to crank after sitting for 12 hours or so. Have changed the spider, plugs wires, plugs fuel pump. Truck run great after it get started and will crank on a 1/4 turn after it once gets started. Has 62 lbs of fuel pressure and 217k miles. Any thoughts would be great.
MT-2500
07-22-2009, 08:57 AM
1999 Suburban is hard to crank after sitting for 12 hours or so. Have changed the spider, plugs wires, plugs fuel pump. Truck run great after it get started and will crank on a 1/4 turn after it once gets started. Has 62 lbs of fuel pressure and 217k miles. Any thoughts would be great.
What is the engine cranking fuel pressure on the hard stat cold?
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.
What is the engine cranking fuel pressure on the hard stat cold?
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.
rondupree1212
07-22-2009, 09:05 AM
One other note. When the gas tank is full and I turn right I get a strong smell of gas.
MT-2500
07-22-2009, 09:35 AM
One other note. When the gas tank is full and I turn right I get a strong smell of gas.
A smell is a gas leak.
On the smell look and smell around for where the smell is coming from.
Post back them fuel pressure readings.
A smell is a gas leak.
On the smell look and smell around for where the smell is coming from.
Post back them fuel pressure readings.
rondupree1212
07-22-2009, 09:49 AM
It smells like its coming from the rear of the truck, but i have never seen any sign of a gas leak.
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