I have a 96 Suburban that has been very reliable up till this morning.

I tried to start it and it will crank but won't start.

It has 180,000 miles and had the fuel pump replaced at 130,000.

My wife drives it and she said it has had a hesitation when the go pedal was applied in the last week but it drove and started fine till today.

I suspect it's the fuel pump,which is going to be a fun job considering I filled up that big *** 42 gallon tank 40 miles ago.

Any help would be appreciated. Dave

 

well use a when you got that much gas in the tank use a motorcycle jack to support the tank, was the sending unit replaced at the same time as the fuel pump? if not that is probobly what the problem is, i worked on a 96 vortec for a buddy a while back and it was doing the same damn thing that u descibed as above, i relaced the fuel pump and it did the same thing with a new feul pump and i droped the tank again and replaced the sending unit and it cured the truck. hope thats going to help.I have also noticed that these motor expierience a lot of troubles from your mileage on up, might wanna get it off your hands before to long.

 

I'm not certain if the sending unit was replaced along with the pump.I didn't own it then,I can call the original owner and find out.

What other problems are you referring too with these trucks.I just bought it 8 months ago.

 

ive been through 3 fuel pumps in my 96.... its a pain even w/ a lift. im fixing to drop in my carbed ls1 out of my bonneville so im not gonna have to deal with it any more

 

I hope you changed the fuel filter since then. Mine was pluged after 5000 miles after a change. And the thing would not run. I would change the filter and check to make sure your gettin fuel to the injectors at the intake.

 

Go thru the usual check list, does the fuel pump prime for 2-3 seconds when you turn the key to run? What is the fuel pressure?
If it doesnt, wit the key in the "RUN" position, give the tank a few good whacks with a rubber mallet. Choose you strike locations wisely, being so full wont help.
Clogged fuel filters kill these pumps.
I am at 310,000 lilometers and still am on the original. I change my filter everyyear. You would be surprised on how dirty fuel really is.

If you put a Johnson bar and socket on the crankshaft, and wit the key in the run position, when you turn the crank 1 turn, the pump will prime. There is some connection with the crank position sensor and the fuel pump.
Normal Vortec fuel pressure is 55-65. The lower end of the scale withthe engine idleing throttle closed, should jump up when revved as the manifold vacuum decreases.
There is also an oil pressure switch that cam malfunction causing the pump not to run. The PCM think that there is no oil so it wont run as it is trying to save the engine from destruction.

Could be the fuel pressure regulator. I bought a cheap $30 fuel pressure gauge. It is very handy, it has a button you can push to releive thefuel rail pressure as well.




If you are going ti get into the injectors, you might as well install the newer GM MPFI Conversion.
Scroll down in this thread, the old and new injector spiders are above 1 another. the upgrade has the 8 thicker lines on the spider. There is a good Marine intake and stock truck intake comparison photo also.
https://www.performancetrucks.net/fo...d.php?t=356743

Good picture of GM MPFI conversion kit:, includes the 8 injector spider, new fuel pressure regulator and gasket set.
http://www.pacificp.com/forum/viewtopic.php?t=981

Some more pics of the intake and upgrade
http://www.pacific-audio.com/perform...es/231640.html

The old poppet spider has the "injectors" in the central hub of the spider, the new spider is an actual TRUE Multipoint Electronic Fuel Injection (MPFI) system. You simply take the old 1 out and install the new fuel pressure regulator and the injector spider. You only have to remove the upper plastic intake, not the lower. Not a bad job I have heard.

Here are the prices and p/n's
Part Numbers and costs.
Hope this helps. Let me know if you need anything else I have lots of pics. I got these items from GMpartsdirect.com

Part: 93441235
Category: Fuel Injector
Description: INJECTOR
Min.Qty: 1
Unit Price: $188.34
Quantity: 1
Ext.Price: $188.34
Core Charge: $0.00
--------------------------------------------------------
Part: 93442096
Category: Fuel Injector
Description: BRACKET
Min.Qty: 1
Unit Price: $7.06
Quantity: 1
Ext.Price: $7.06
Core Charge: $0.00
--------------------------------------------------------
Part: 17113206
Category: Manifold Gasket
Description: SEAL KIT
Min.Qty: 1
Unit Price: $19.60
Quantity: 1
Ext.Price: $19.60
Core Charge: $0.00
================================================== ================

SUB TOTAL: $215.00
SHIPPING: $49.03
TAX: $0.00
TOTAL WITH TAXES: $264.03

This is extremley inexpensive. I replaced 3 injectors in my L31 Vortec 350 and they cost me $100 a piece from my local GM dealership. This was befre this MPFI upgrade was available, if it was available I would have done it in a heartbeat.

The MPFI Conversion has the same fuel flow rating as the stock poppets which is 19 lb/hr.
The conversion helps with idle and throttle response as well as driveability. I fthe stock spider or FPR is not 100% fuel mileage and power will also increase.

peace
Hog

 

Thank you for the informative response Hog.

I swapped the fuel filter and it's running fine now.I'm going to run this tank of fuel out and swap it again.

I drained the gas out of the filter and it was a nasty looking,dirty brown.

It took me a grand total of 10 minutes of work to get it back on the road.


I like easy fixes.

 

I just drove it again and there is a hesitation at throttle tip in.

Anyone know what this could be?

 

If you have changed the fuel filter again, I would give it a few days to relearn how to fuel the truck again after being starved for so long.

It may fix itself.

peace
Hog