bravada wont start when warm

[oak2001raid]

Most of those problems you told me about involved the fuel pump.. If i was going to do that, do you think it would be a good idea to go ahead and change the pump?

[old_master]

OEM fuel pumps are typically good for about 100,000 miles, anything over that, consider it a bonus. With that in mind, if you can't confirm a problem with it, consider the mileage. If it's close to, or over, I'd replace it simply because it's bound to fail shortly, and the tank is down anyway. If you do replace the pump, do yourself a huge favor and use AC Delco or Delphi. They do cost more, but it beats doing the job again in a couple of months.... when it's cold outside. So, bottom line, take my advice and do what you want

[oak2001raid]

I really do appreciate your advice, I hate to keep asking but before I spend 300 on a fuel pump. Do you think that is likely to be my problem?

[oak2001raid]

oh... there is 135k miles on it

[old_master]

Originally Posted by oak2001raid

...I can hear the pump kick in when It wont start, but Im getting very low 20psi fuel pressure...

This could be an important clue but, like I mentioned, it could be a poor electrical connection causing it. The electrical connector at the fuel pump module is a known problem area. If the connection loosens up from vibration while driving, the terminals get hot from the high resistance and melt the connector. Also, as the pump motor wears, the motor draws more current and the higher amperage draw creates heat and adds to the connector problem. It also causes the motor to wear faster contributing to its own demise. Eventually the connection burns to the point that the motor can no longer get battery voltage and quits totally. Replacement fuel pump modules come with a new style connector. They supply crimp connectors for splicing the new connector to the existing vehicle harness. DO NOT use the supplied connectors. Solder the connections and use heat shrink tubing to "weatherproof" the connections.


The fuel pressure spec for the CSFI engine is 60psi to 66psi. The poppet nozzles at the intake ports require 40psi before they will open and squirt fuel so anything less than that, the cylinders will not receive any fuel. Typically on a cold engine, if fuel pressure drops below 60psi, it will be hard to start and there will be performance issues when it does run. If fuel pressure drops below approx 55psi, you can usually get it to start by spraying some carb cleaner in the throttle body, but again, there will be performance issues when it runs. If fuel pressure drops below 50psi, even the carb spray might not get it running.

If the fuel pump is original at 135,000 miles, an "educated guess" would be that a faulty pump is what's causing the problem. Bottom line is that without a complete diagnosis, it's a $300 guess Hope this helps.

[oak2001raid]

yes that does help.. I am going to drop the tank today to check the connections. I will let you know what I find out

[oak2001raid]

the electrical connections seem to be fine. they were very tight, and clean. I didn't see any burnt spots or any signs of heat.

[old_master]

When you got the 20psi reading, was that while the engine was cranking? And did the pressure remain steady at 20psi?

[oak2001raid]

20 psi key on NOT running no increase in PSI when cranking... yes it stayed there

[old_master]

Sure sounds like it's the pump. Do you have any trouble with the fuel gauge not reading correctly? Have you had any EVAP DTC's showing up? The fuel level sender and the fuel tank pressure sensor both come with a new module. If you're not having fuel gauge or EVAP DTC's, you can replace just the pump and it's a ton cheaper. You can get an AC Delco pump repair kit on eBay for around $60. All you get is the pump, no module housing, pressure sensor or level sender.

[oak2001raid]

no I dont have any problems with fuel gauge, or any trouble codes.. I will have to check out Ebay, 60 is alot better than 300. I really appreciate your help and I will let you know how changing the pump works out.

[old_master]

I'll be crossing my fingers

[oak2001raid]

Ok I got a AC Delco fuel pump.. But I cant seem to figure out how to get the other pump from the sending unit. I unclipped the power wires and got the two clips on the side of the unit. Acts like something else is holding it in. Any suggestions

[old_master]

Did you remove the sock, (filter) from the bottom of the pump?

[oak2001raid]

yes, that was the first thing I did. Looks like maybe a fuel line that connects to the top of the pump