My suburban won't start.

[thinger2]

Dont entirely right off the fuel pump yet.
Get the fuel pump test gauge with the TBI adapter.
I believe OReillys loaner has that.
If not, Harbor **** tools is now selling a kit that looks like it has a TBI adapter.
Use a new fuel filter.
Install the guage inline with the filter plumbed in the right direction and the gauge measuring output through the filter.
Find pin "G" on the obd 1 port.
Be very very carefull to not touch anything else.
That port goes to the ECM and if you **** it up you will fry the ecm.
Put 12 volts to it, Look at the pressure and the timing of that pressure.
13 to 15 psi in about less than 10 seconds.
Including pumping out the air.
Probably a good pump.
But on the margine of a long run time.
And dont discount the fuel pump relay either.
They have low volt intermittant contact problems where they internally melt and cause wild and unpredictable random voltage loss.

 

[Schurkey]

In that he knows his fuel pressure is "10.5 to 11.5"; I'm guessing he's got a fuel pressure gauge and knows how to connect it. Using the fuel pump bypass at the ALDL could be very helpful if the problem is upstream of the ALDL wiring. Otherwise he'd get the same results with the ALDL connection as with the regular harness. For example, if the problem were rotted wires inside the fuel tank. It wouldn't matter where you apply power because that power would still have to go through the rotted in-tank harness to get to the pump.

Having variable fuel pressure well under the "14-pound" pressure regulator spring he's installed, tells me the pump or the power-supply/wire harness has problems. I suppose there's an off-chance that the pressure gauge he's using is defective.

Yes, he needs considerably more diagnostics to resolve this. Verifying voltage/amperage/RPM of the pump would have already been done if this were in my garage. Testing voltage delivered to the pump needs to be done as close to the pump as practical. Verifying amperage can be done anywhere in the pump harness--but typically it's done in the same place as the voltage testing.

 

[brianblanton]

I upgraded the spring from amazon to 14-15 psi. The factory original fuel pump worked for about 3-4 months just fine, then it wouldn't start. With 172,000 miles on the original fuel pump, I figured it was time for a change. I put in a precision fuel pump model number E16038. It was then that I added a fuel pressure guage and found it jumping around from 10.5 to 11.5 psi. It is electrically driven. Could the new pump be underpressure?

 

[texas tough]

like the METTALICA song goes... GIVE ME FUEL GIVE ME FIRE GIVE ME THAT WHICH I DESIRE..,
If its spraying fuel, then the computer thinks its getting spark..
when a truck wont start I always check for spark first.
never assume you dont have an ignition problem because you replaced some ignition parts. lots of junk parts out there,

 

[texas tough]

also these truck are set up to run 9 to 12 psi fuel pressure.,, putting the " PERFORMANCE FUEL PRESSURE SPRING ' in will cause you problems.

 

[Schurkey]

It was then that I added a fuel pressure guage and found it jumping around from 10.5 to 11.5 psi.

Have you tested the gauge? Do you know that it's accurate?

It is electrically driven.

"It" what? The pump is electrically driven? The gauge is electrically driven?

Could the new pump be underpressure?

Yes. Anything and everything can be broken/defective/faulty.

Have you ever tested the electrical power supply and the ground for the fuel pump? A perfectly-good fuel pump choked by corroded wiring will not supply proper pressure or volume.

 

[Schurkey]

also these truck are set up to run 9 to 12 psi fuel pressure.,, putting the " PERFORMANCE FUEL PRESSURE SPRING ' in will cause you problems.

I don't know that that's true; so long as the regulated pressure isn't higher than the pump is capable of, and that the truck actually needs more fuel pressure. At least one member here has run 28 psi on his TBI, and has posted the photos of his fuel pressure gauge as proof.

I've shimmed the stock spring in mine for a little extra pressure; mainly because I'm too cheap to blow $25 on a $1.50 spring.

 

[brianblanton]

I haven't checked the electrical power supply and ground at the pump. The fuel pump is electrically driven. The guage is just inline on the 3/8 inch line. I haven't checked the guage for accuracy. I guess I could go online to amazon and buy another one.

 

[brianblanton]

I found out that the parts house sold me the INCORRECT fuel pump. I asked for one that could put out 28 psi. He read the wrong thing on the screen and read 28 gph. Man, what an ordeal! I will keep the fuel pressure regulator inline in case I want to upgrade the tbi in the future. Just Phew!

 

[brianblanton]

Ok. This is very uncomfortable. I put a 17 psi pump into my suburban, and it only reads 12 psi. is there any way the computer could be controlling the psi of the pump? I am at a loss for where to go from here. help!