97 Suburban - Fuel issue? Please help!

[v8_ranch]

Wife was driving our 97 Suburban a couple of days ago and it died whiel she was driving it. Truck is 97 4x4 1500 with 350 Vortec. Truck woulkd turn over and intermittently start, but immediately die.

The fuel pump makes noise when kety turned on, for about 3-5 seconds.

Fuel filter was just replaced about 5000 ago, but I replaced it anyway last night. No change.

So, I decided to replace fuel pump, if for nothing else, the truck has 200,000 miles on it. Finished getting it installed and put in about 5 gallons of gas. Duid teh same thing on first few tries... start but immediately die. I figured it might have to purge air a little bit. Tried a few more cranks, but nothing, not even a start and then immediate stop this time.

broke line on outlet of filter and it has gas there.

Let it rest today while travelling to airport. Came home and it started, but then died immediately again. Next few cranks, nothing. I have read some threads on here that mention the fuel regulator as well. I am wondering if I went down the wrong path depsite my symptoms. Glad I tackled it though. What a major sticking pain in the rear.

Pump still comes on for 3-5 seconds when key turned on...

Any ideas or helps greatly appreciated. Need to get this thing running. I have a pressure tester, but not sure where the test port is, if a 97 has one even. anyone haev a picture they can post or email to me. [email protected]

Thanks

[v8_ranch]

oh yeah, the new pump is a Delphi model. I got it at O'Reilley's

[MT-2500]

Test port should be on the fuel in line on rear of engine.
Or you can tap in the fuel filter in or out line.
Post back you 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.

MT

[j cAT]

Originally Posted by v8_ranch

Wife was driving our 97 Suburban a couple of days ago and it died whiel she was driving it. Truck is 97 4x4 1500 with 350 Vortec. Truck woulkd turn over and intermittently start, but immediately die.

The fuel pump makes noise when kety turned on, for about 3-5 seconds.

Fuel filter was just replaced about 5000 ago, but I replaced it anyway last night. No change.

So, I decided to replace fuel pump, if for nothing else, the truck has 200,000 miles on it. Finished getting it installed and put in about 5 gallons of gas. Duid teh same thing on first few tries... start but immediately die. I figured it might have to purge air a little bit. Tried a few more cranks, but nothing, not even a start and then immediate stop this time.

broke line on outlet of filter and it has gas there.

Let it rest today while travelling to airport. Came home and it started, but then died immediately again. Next few cranks, nothing. I have read some threads on here that mention the fuel regulator as well. I am wondering if I went down the wrong path depsite my symptoms. Glad I tackled it though. What a major sticking pain in the rear.

Pump still comes on for 3-5 seconds when key turned on...

Any ideas or helps greatly appreciated. Need to get this thing running. I have a pressure tester, but not sure where the test port is, if a 97 has one even. anyone haev a picture they can post or email to me. [email protected]

Thanks

disconnect the MAF see if it starts....also if the ECT engine coolant temperature sensor is bad you will get this problem...so if fuel pressures check out go here...

[v8_ranch]

I disconnected the MAF and tried it and nothing. I will hook up gages around 1230 today and report back. It is back to turn key on, you can hear fuel pump run for a couple of secs and then turn off, turn key to start and just cranky cranky cranky...

One question I have is about the oring seal on the top of the tank. When I replace teh pump yesterday, the new seal sat in the recess fine, but I just wondered if by chance that did not seal properly, could it be causing this? I would not think so, but thought I would ask anyway.

Also, is there a way to check the ECT?

Finally, one other question. In reading through the various posts on this topic, I came across something regarding the Oil Pressure Sending unit being bad could cause the same thing. I think that is what I read anyway. I have noticed the last couple of times I drove this vehicle that the oil pressure gage would kind of vibrate around a bit, not all the time though... I think it may have acted that way whenever you were accelerating, but again, it would just be for a bit and then steady out. Any chance this could have something to do with all of this mess?

Thanks all

[v8_ranch]

OK, forgive me, as I am a bit sleep deprived, but I think I just noticed somthing new, going along with the last part of my last post...

I wanted to try cranking it one more time really watching that oil gage. I went out, cranked it, no start, but here is new thing I noticed:

1. when I turned the key on, the check gages light came on (the check engine light is also on. I saw this lighht on when I disconnected the MAF, but thought it was due to that. MAF is plugged back in and it is will coming on?

When I start cranking, the check gages light goes off, and the oil pressure gage is what is bothering me now - it stays at 0 for a sec and then hops up to maybe 5, and then to 10, and then tops out at 20 for the rest of the cranking (cranked for about 20 seconds to watch it - a couple of times, same thing). The action on it is like I mentioned in previous post, very racthety.

Stop cranking, and check gages light comes back on

[maxwedge]

Test the FP see what's what first, as mentioned.Don't expect normal oil pressure responses at engine cranking speeds.

[v8_ranch]

Got my fuel pressure tester out. Found the capped test port. Removed it. Dry (guess it is supposed to be, right?). Found the fitting on my tester that threaded on and turned key to on - nothing. I mean 0 psi.

I am wondering if it is my tester. The tester is a near new Matco Tools FIT13APB. But, on my literature, the closest thing to Chevy or GM is Cadillac EFI and DEFI. The fitting threads on perfectly, but wondering if there is a stem or something that should insert properly, that perhaps is not due the possbily wrong fitting. Any ideas?

[j cAT]

Originally Posted by v8_ranch

Got my fuel pressure tester out. Found the capped test port. Removed it. Dry (guess it is supposed to be, right?). Found the fitting on my tester that threaded on and turned key to on - nothing. I mean 0 psi.

I am wondering if it is my tester. The tester is a near new Matco Tools FIT13APB. But, on my literature, the closest thing to Chevy or GM is Cadillac EFI and DEFI. The fitting threads on perfectly, but wondering if there is a stem or something that should insert properly, that perhaps is not due the possbily wrong fitting. Any ideas?

the hose needs to push on the valve like the tire valve stem to open the port for guage to read pressure....if you push on that stem gas should squirt out ...


the ECT is checked by reading the ohm value should be in the hundreds of ohms approx...do not remove this to read just remove the connector...


this engine will start then stall correct?????

[v8_ranch]

Originally Posted by j cAT

the hose needs to push on the valve like the tire valve stem to open the port for guage to read pressure....if you push on that stem gas should squirt out ...


this engine will start then stall correct?????

Geeze, now I feel stupid... OK< so there is another line on a 1997 on the pax side for the FP pressure? I was on the vent if I understand you correctly. The vent connection is the one on driver's side towards firewall?

The engine the last few times will not even start and stall. It is very hit or miss now. I did try a little gas in the intake and it starts right up and runs until gas is gone. So spark has to be good, and it is defintely NOT getting fuel...

I will try to find the correct FP pressure port in the morning.

Thanks all

[j cAT]

Originally Posted by v8_ranch

Geeze, now I feel stupid... OK< so there is another line on a 1997 on the pax side for the FP pressure? I was on the vent if I understand you correctly. The vent connection is the one on driver's side towards firewall?

The engine the last few times will not even start and stall. It is very hit or miss now. I did try a little gas in the intake and it starts right up and runs until gas is gone. So spark has to be good, and it is defintely NOT getting fuel...

I will try to find the correct FP pressure port in the morning.

Thanks all

if you find that there is no fuel pump running check for power to fuel pump and that includes the ground wire...

[v8_ranch]

Originally Posted by j cAT

if you find that there is no fuel pump running check for power to fuel pump and that includes the ground wire...

Pretty sure it is running, as I can hear it when I turn the key to ON. Runs for a couple of secs and then off again.

[v8_ranch]

Am I hooking up my gage to the right spot. I was hooking it up to the port under the black cap on the two fuel lines taht come up and over the intake manifold on the driver side of the engine. SOme mechanic told me the FP pressure port should be on the pax side instead. I cannot see anythign over there on the pax side...

[jnorth]

sorry I can't help with the test port but the '2' second pump prime does not equate to a functioning pump. As far as I'm concerned that only confirms there is initial power making it to the pump, and not even a warranty after that. I heard from one local he went through 2 new ones (aftermark mind you) right off the shelf that didn't work, before getting a working 3rd.

[j cAT]

Originally Posted by v8_ranch

Am I hooking up my gage to the right spot. I was hooking it up to the port under the black cap on the two fuel lines taht come up and over the intake manifold on the driver side of the engine. SOme mechanic told me the FP pressure port should be on the pax side instead. I cannot see anythign over there on the pax side...

ok so now that the gauge is hooked up is there any pressure???