Major problems??? Fuel pump or time for new computer?

00GTP*LIFER* · #1 01-12-2009, 12:32 PM

Okay I am in serious need of a starting point to hopefully tackle this problem. I have a 2000 GTP, 164,XXX, I just bought it with 155,XXX( i was my own salesman at the dealer i worked at). No after market mods.
Okay so car ran great started everytime no struggle then one day i stopped for about 10 minutes and when i came out and tried to restart the car it started then chugged itself to death about 20 seconds later and would not restart. I gave the gas tank a few bangs and it started right up. I put a bottle of lucas fuel injector cleaner and full tank of 93 octane(ALWAYS by the way). Problem went away. Happened occasionally for the next week. Well it was fine since may now last week it started again only this time the bangin on the tank didnt seem to work, after about 6 or 7 failed attempts it started and was fine for a couple days. The last time was the other day it was difficult to start all day then finally stalled at a light and would not start up. Got it home and went the next morning to start it up. would just crank but not turn over. put a jump box on it and it started but wont stay runnning more then five minutes without chugging itself to death....any advice???

brcidd · #2 01-12-2009, 12:43 PM

Sure sounds like a bum F/P ... Next time it won't start- spray some carb cleaner in the intake snorkel-- see if it runs and dies....this would be proof positive of a fuel delivery problem. Also get a fuel pressure gauge on it- and/or listen for fuel pump activation key on engine off for 2 seconds....

If it's never had a F/P it is past due.....

BNaylor · #3 01-12-2009, 12:47 PM

Your GTP has a two speed fuel pump. There is a speed control relay in addition to the main fuel pump relay. Swap those out since they are the same to rule the relays out which are controlled by the PCM module. Also, try the fuel pump resistor bypass procedure at the link below from our Grand Prix Tips & Maintenance forum.

Fuel Pump Resistor Bypass '97-'00 GTP

And welcome to AF.

richtazz · #4 01-12-2009, 12:58 PM

Welcome to AF

I agree that it sounds like a bad fuel pump. Luckily, your car has an access panel in the trunk so you don't have to drop the tank to swap the pump.

BNaylor · #5 01-12-2009, 01:08 PM

Before replacing the fuel pump since it is big bucks for the Delco or aftermarket replacement do the easy things first and that includes replacing the fuel filter if it has not been done as preventive maintenance. Also, based on your symptoms it could be the fuel pump resistor so try that to rule it out.

If it is the fuel pump then check out our Tips & Maintenance forum.

Click here

richtazz · #6 01-12-2009, 01:42 PM

I thought about suggesting the resistor bypass, but since banging the tank worked a few times, I figured the pump is shot.

00GTP*LIFER* · #7 01-12-2009, 03:10 PM

The banging the tank worked a few times correct. However I am going to go home now and tinker with it. Im going to try to put it in high mode and see where that takes me. How come i have full power to the car though like lights radio everything and when i try to start it, it will just click but if i put the jumper box on it she will fire right up no trouble from the fuel pump or anyhting but will chug to death after 2 or 3 minutes all battery terminals are tight too!

BNaylor · #8 01-12-2009, 03:27 PM

Thats sound like you have a flaky battery even though you get the instrument lighting. Get it along with the rest of the charging system (alternator) properly tested. Proper fuel pump prime depends on the battery charge. The cold weather will affect the battery if it is weak, low specific gravity or a bad cell.

00GTP*LIFER* · #9 01-12-2009, 07:32 PM

Ok so I went out to the car and i tried bending back tab 85 on the relay as said. I did need a jump to start the car and it started but could not even last 15 seconds without chugging to death so maybe the battery could be the issue and i am almost positive this fuel pump is sneaking its way in there

BNaylor · #10 01-12-2009, 08:28 PM

The fuel pump is possible but easy to troubleshoot at least electrically. With Tab 85 bent you will have a full 12 volts at the electrical located on top of the fuel pump pod. Just remove the access cover in the trunk, probe the hot and ground for 12 volts. If the 12 volts is present at fuel pump prime then the fuel pump is suspect. Also, as pointed out you will hear the fuel pump prime for approx 2 seconds with ignition to RUN. Let me know of you need the pin configuration and wiring color coding. The fuel level sensor also uses the same connector so there are at least 4 wires at the connector.

00GTP*LIFER* · #11 01-14-2009, 01:11 AM

Okay so I went today and pulled the battery out brought it to auto zone and of course it was shot. Bought the new one put it in and the engine cranks now but still wont turn over. It is like -20 degrees with the wind chill(not to mention the foot of snow thats accumulated around my car) here and I have been toughing it out in a cold parking lot with this. So I towed it to my mom's and garaged it. Tomorrow first thing I am going to go out and take the panel off in the trunk give it a good inspection and go from there. I'm assuming its going to need replacing and I guess at this point I'm ok with that. Im not a mechanic by any means so if you have any pointers please let me know I'd appreciate it. And I am not a complete retard either, with a repair manual and a little bit of guidance from you guys here at AF I think I will be just fine by end of the day tomorrow.

wlkjr · #12 01-14-2009, 07:55 AM

Quote:

Originally Posted by 00GTP*LIFER*

Okay so I went today and pulled the battery out brought it to auto zone and of course it was shot. Bought the new one put it in and the engine cranks now but still wont turn over. It is like -20 degrees with the wind chill(not to mention the foot of snow thats accumulated around my car) here and I have been toughing it out in a cold parking lot with this. So I towed it to my mom's and garaged it. Tomorrow first thing I am going to go out and take the panel off in the trunk give it a good inspection and go from there. I'm assuming its going to need replacing and I guess at this point I'm ok with that. Im not a mechanic by any means so if you have any pointers please let me know I'd appreciate it. And I am not a complete retard either, with a repair manual and a little bit of guidance from you guys here at AF I think I will be just fine by end of the day tomorrow.

Not sure about your terminology of "cranks but won't turn over". Sounds like it turns over but won't crank, or start running.
You probably need to check the fuel pressure at the valve on the fuel rail. And make sure you have plenty of gas.

00GTP*LIFER* · #13 01-15-2009, 01:20 PM

Ok so I am stuck I got the old fuel pump out through the panel in the trunk, and the new one ready to put in I just cant get it flush in the tank to lock the snapring. I been trying for an hour and it just wont go in....Any tips Please....

00GTP*LIFER* · #14 01-15-2009, 01:23 PM

Anyone know why the pump wont fit flush to the top of the tank. I cant get the snap ring back in place

BNaylor · #15 01-15-2009, 01:38 PM

Quote:

Originally Posted by 00GTP*LIFER*

Anyone know why the pump wont fit flush to the top of the tank. I cant get the snap ring back in place

You probably have it cocked to one side. Remember the pod is spring loaded and the fit must be just right or straight up and down in the gas tank. Also, it would help to lube the o-ring with silicone grease or vaseline. Once the pod is aligned properly push hard down and the snap ring will snap into place.

BTW - Your new post has been merged with the older one on the same issue.

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