Sis called me today and told me her 99 4 door Tahoe (GMT400 style) is hard to start, and when she tromped on it to pass someone, it chugged chugged chugged and then went. Fine in summer, acts up bad in winter. Labors to crank, then cranks quick. Current mileage around 130K.

I've got a sneaky suspicion its that Junk Airtex fuel pump I had to put in last year. (It was an emergency, so had to buy what I could get).
After putting the new pump in and changing the fuel filter at the same time, her fuel pressure at idle was fairly low - around 42 psi which I thought was odd for a brand new pump.

When I call the dealer, they ask me for a VIN, but won't give me the part number of the fuel pump I need.

There are a few available.

AC Delco # MU1777 4 Door Code GFV
AC Delco # MU150 4 Door Code GFV

All GFL options seem to be for 2 doors.
From what I remember, she does not have the robust fuel system
GFU seems to be without an RFI filter

Can someone help me out on which pump to pick for this?
I'm going to check the fuel pressure on it now to see what I have.
Also going to order new plug wires.
New battery as of a year ago so it should be still good - going to load test it.
Cap/Rotor/Plugs replaced about 20K ago.
Any other thoughts?

 

I thought mabee the alternator wasn't charging, and took it to Autozone. THey confirmed the alternator was bad... So I swapped it with a new one since it was under warranty.

Problem still exists.
Any thoughts???

 

buy the delphi unit from napa, they come with the new harness plug so it shouldn't matter which one you get.

 

my truck has a new Delco fuel pump, went in with no issues, like bigbrown said, it comes with a plug so it'll go in no problem. Swap the fuel pump, filter and check the regulator on the CSFI spider. If it's going to die soon, change it asap with the "revised" CSFI spider, which has 8 individual multec-mini injectors in it as opposed to the OEM "poppet" bullshit. I did all these things and the truck runs strong, fuels well even with a pretty aggressive cam, and it's all OEM parts.

edit: I think OEM spec for fuel pressure is around 60-65 psi.

 

Ended up being the Starter Motor, and the Distributor Rotor. Cleaned the rotor and problem went away almost completely.
Going to swap wires when they come in.

Fuel pump was still holding good pressure.
Spec on her 99 Tahoe is 60-66psi when commanded on, 55-60psi when it shuts off, with the engine off. It sits around 55psi, then starts to slowly bleed down.
Supposed to be 55psi when idling, and it was around 54-55 psi.

The starter was the main issue. Fixed it over the holiday and it's been running decent since.
Thanks!