99 chevy not getting fuel pump and relay are new s

[joneida2906]

So I have a 99 chevy suburban 1500. Replaced fuel pump back in Feb.(present day) as it started to get cold the truck took longer to start. If i turned the key on for about 5 seconds it would start as it was a new truck. about 4 days ago it started then cut back out about a second later. Jumped right into it and changed fuel pump again under warranty( the pump was not cutting on so i asumed it was it) Changed relay and fuel filter still nothing. I am getting power to the pump for about 1 sec then the power stops the pump actually never cuts on though but their is power for that sec checked harness pulled pump off and checked it everything works when hooked up outside the truck (directly to battery) At this point im stuck and dont know what else to try. It blows me away that i am getting power then it goes away without making the pump work. anyone have any ideas beside the ones that i have tries thanks a lot John

[777stickman]

John: Welcome to AF. With key on and engine off you should have power to the pump for about 2 seconds. This is normal. From your post I would look very closely at the ground signal from the pump connection. This would be a black wire connected on a cross frame rail forward of the tank.

Good luck and please let us know.

[joneida2906]

i tapped into the ground wire on the harness and grounded onto the frame . Also does the ground wire on the harness go to the frame or does it follow the harness to a place that meets multiple grounds

[j cAT]

Originally Posted by joneida2906

i tapped into the ground wire on the harness and grounded onto the frame . Also does the ground wire on the harness go to the frame or does it follow the harness to a place that meets multiple grounds

with a 5.7L 1999 engine you need the proper fuel pressure. what is the fuel pressure? DOES fuel pressure hold KEY ON ENGINE OFF ?????

IF IT RAPIDLY DROPS then the fuel pump/injectors/regulator are leaking .

put gage on fuel filter . does the pressure hold ? if not the pump is bad.

who made the pump ?

the ground wire at the frame rail fuel tank must be clean and secure just like the relay and fuses supplying the positive side of the circuit..

good ground and feed are required . unsoldered splices are not allowed.

having pressure means nothing . you must have the correct pressure.just a few psi low NO START .

[joneida2906]

its an Airtex pump and it the second one (changing fuel pump is easy on this truck so i Changed it first. the pump is not turning on but am getting power for a sec or so. also laet time i messed with it , it sat overnight and i turned the key and it started for a sec then turned off. Can i messure fuel pressure even if the pump is not working? Thanks will check make solid ground.

[joneida2906]

does anyone know how to disable or reset the security? I have heard that it may have something to do with the fuel pump

[j cAT]

Originally Posted by joneida2906

its an Airtex pump and it the second one (changing fuel pump is easy on this truck so i Changed it first. the pump is not turning on but am getting power for a sec or so. also last time I messed with it , it sat overnight and i turned the key and it started for a sec then turned off. Can i messure fuel pressure even if the pump is not working? Thanks will check make solid ground.

whats going on here is you used a pump from a manufacturer that is well known to us here to be the most defective scam automotive part made.

EVEN IF I WAS GIVEN AN AIRTEX PUMP FOR FREE I WOULD PUT IT IN THE TRASH !

WHAT you need is the delphi pump for your vehicle. or the ac delco .

with fuel issues you must use a pressure gage.

the fuel pump comes on for 2 sec . when cranking .if no start you must recycles the key . that means key off then back on .then you get another 2 sec.

with the gage on the fuel test port you observe the pressure.

so what pressures did you get ? this is the 5.7L engine ?

[joneida2906]

I cant get the pump to turn on even for a second. I get power for sec but have not tested with volt meter so may not be putting enough voltage to turn on pump. I dont think i can test pressure without it actually pumping fuel into the lines. Also i know you may not like Airtex but the pump does work when i hook it up directly to a battery it pumps like crazy. Not saying its an awesome pump but i have it and it was under warranty through Advance. Thanks and do you or anyone know how I can disable the ABS and the Security Sysem. I need to find both control Modulars and try to disable the security system. Thanks for everyones in put and it much appreciated and any other ideas will defiantly be tried out and i let everyone know how it goes.

[j cAT]

with the pressure gage connected and a voltmeter on the pump relay contact turn key to ignition on no crank. what is the pressure / voltage ?

check this also at the pump connector for voltage.

the security system may cause the engine to start then quickly die. you will get the security light to be on when this sercurity system screws up. there is no reset if this security light is on . you will have to get this removed. best have an auto motive locksmith skilled repair guy do the bypass . it is a common well known fix with the proper tools and skill not much time or cost.

if this is the key security issue most would have this posted as a security light no start issue.


you do not want to repair this as OEM , this would cost about a 1,ooo.oo..............remove this security system !

[777stickman]

Is your truck an Old Body Style (like a '96) or a New Body Style (like an '01)? Also you need to tell us what engine!! Generally speaking the Security system will disable the injectors and not the pump. Try replacing the 20a ECM B fuse in the underhood fuse block. This fuse supplies batt voltage to the pump thru the relay. Fuel pressure can only be checked with an operational fuel pump.

What I've said here applies to Old Body Style's only.

[joneida2906]

Old body style 5.7L all fuses are good

[777stickman]

Originally Posted by joneida2906

Old body style 5.7L all fuses are good

So does that mean you're not going to replace this $0.50 fuse to be sure?

If that's the case then I'm done here and good luck to you.