: fuel pump info please

03-29-11, 10:50 AM
Hey everyone, could some of you guys give me some of the symtoms of a failing fuel pump? The eldo has issues at higher rpm's e.g.surgeing or pulsating , i have changed the filter & the injecters were deemed ok by gm mechanic about 5000 miles ago. I'd like to step into that N* without damaging it sometimes,especially when one of those wanton bugs tries to beat me off the ramp! Hail! Hail! to N*'s everywhere, aint 4k rpm's grand! i'm used to big block chevy, gots ta have my V8........ideas please

03-29-11, 12:06 PM
Check the fuel pressure. That will tell the tale. Symptoms are stalling or stumbling, especially at high fuel demands. If you go WOT and it falls flat on it's face like a carburetor with a bad accelerator pump (remember that?), then it's pretty sure to be a bad pump, but a fuel pressure test is the positive way to diagnose it.

03-29-11, 12:46 PM
thanks Ranger, I found the check port, i've been calling the local auto parts store to see if they have a regulator on the loan program but no luck yet..i'm going to have to call my stand-by mechanic and see if he has one.... if it is bad, the way i see it is it cant be much more difficult than a late 80's or early 90's camaro pump...more wires maybe. do you think the b2s1 has any role in this? it does'nt come on until i get on it . thanks for the imput..p.s. what is the correct psi?

03-29-11, 01:08 PM
Your fuel rail pressure at key:ON should jump to about 40 psi. Running: 43 - 45 psi.

The pressure regulator is in the rear run of the fuel rail - hairpin clip and 2 internal O-rings. The pump module is in the fuel tank - it has to be dropped for your year, I believe. Later models had a hatch in the trunk floor - check first.

The module - pump, level sensor, and tank pressure sensor is listed in RockAuto - the Airtex brand will most likely be an OEM DELPHI complete unit with upgraded wiring harness and plug. (I have 2 on the shelf, one with the upgraded harness, the other with the stock electrical connector.)

B2S1 is an O2 sensor code - maybe fuel mixture related, but why only one side (the front, or left) of the engine ??

03-29-11, 02:29 PM
Sub i think that the Eldo's never got the hatch threw the floor or trunk to get to the fuel pump i think the Seville and Deville where the only ones ever fited with a hatch for easy access without dropping the tank

03-29-11, 04:34 PM
Yup, no access panel on the Eldos.

03-30-11, 10:34 AM
thanks everyone, good news, the pump is hittin' 43-44#.. thanks for the info, seriously I'm taking down ALL info recieved about my caddie..on the pulse issue let me go back a couple of years and retrieve this,one of my sons' camaro would run fine in town but once on the highway at about 65or so it would fall flat on its 350 face, it ended up being the cat almost totally plugged. Is there a way to check that as a possibility?Does the cat have to have its inerds to let theN* function properly? I have the tools to do an inerd-dectomy on it if that would help, however if its not recomended and thats the problem I will replace it. Anyway Chris said to put some techron in the tank so I did, 10 ounces per 15 gal, so i put 14 oz for a newly filled tank, since the b2s1 still lit up I've been doing a couple of kick-downs on the interstate, although it still surges alittle I must state how cool it was(like kool-aid picher says OH YEAH) . Heres my vin if it helps1G6EL12Y8XU608246, thanks everyone

03-30-11, 12:31 PM
The only way I know of to test the CAT is either disconnect it and see if it runs better or use an exhaust back pressure gauge. I think it is installed in place of the pre CAT O2 sensor.