1996 Riviera Fuel pump fue issue

Tiny
TRUKINDAVE
  • MEMBER
  • 1996 BUICK RIVIERA
  • 200,000 MILES
Hello and thanks for helpin me on this the fuel pump fuse keeps popping, I drive sometimes after 20 miles it pops. I have went through 7 fuses in 800 miles. I just drove from Cincinnati to Evansville without any issues 240 miles. 1 fuse blew when I got there I replaced it, It drove another 50 miles Fuse popped. Now when I replace the fuse and just turn the key on it pops instantly. Here is what I have done so far. Removed wiring harness from the fuel pump - Fuse still pops when key turned on. Removed ICM - fuse still pops when key turned on. The car when its running starts and runs great until when the fuse pops.

Engine is a 3.8 supercharge
Wednesday, January 4th, 2012 AT 12:23 AM

13 Replies

Tiny
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  • MECHANIC
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Replace that fuse with a pair of spade terminals, then use two small jumper wires to connect them to a 12 volt light bulb. When the circuit is powered up and the short is present, the bulb will be full brightness so don't let it touch carpeting or plastic door panels.

Now you can unplug and move stuff to see what makes the short go away. When it does, the bulb will dim. It won't go out completely because current will be trying to flow through the pump motor instead of the short.

Look under the carpeting over the center console area and under the driver's foot area. GM has had a lot of wiring in those areas rub through and cause intermittent shorts.
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Wednesday, January 4th, 2012 AT 12:50 AM
Tiny
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I just removed the fuel pump relay and replaced the fuse and when I turned the key on it didnt pop the fuse. So does that mean that the short is between the Fuel pump relay and the fuel pump harness?
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Wednesday, January 4th, 2012 AT 3:04 AM
Tiny
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Someone mentioned Fuel pump control module that is in the trunk that may be shorting out: Here is what they said:

The fuel pump control module is located above the left rear well. There is a way to bypass the module to see if it but dont leave it like this. You can damage or burn out your fuel pump prematurely. At the fuel pump module connector you need to jump

Pin 6 gray to pin 8 lite green - These 2 wires bypass the power to the pump through the module

Pin 4 black wire to pin 5 pink wire these 2 wires bypass the ground to the fuel pump through the module

There should be one more wire which is pin 7 brown wich is what the computer uses to pulse width modulate the pump. Dont worry about this wire just jump the wires I mentioned above
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+1
Wednesday, January 4th, 2012 AT 3:44 AM
Tiny
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I'm not familiar with that module. We all know the engineers who design cars are all insane. No other car needs a module to control the fuel pump. Wish I could help you better, but frayed and rubbed-through wires in the passenger compartment are real common on GM cars. Unfortunately, any computer module adds a whole new level of complexity and unreliability to our cars.

If you could get it to where the short is constantly present, simply unplugging that module would identify it. If the fuse still blows, or my test light is still bright, you would know the module is not the cause.

You can't really approach it that way when you have to drive the car to make the problem act up. You might consider finding a used module in a pick-your-own-parts salvage yard and popping it into your car. If the fuse still blows, you'll know the module isn't the cause. You're lucky it isn't a miserable newer car. Computer modules must be coded by the GM dealer before they will work, and you must buy new ones. Used computers won't work.
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Wednesday, January 4th, 2012 AT 4:01 AM
Tiny
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Problem resolved: It ended up being a bad Fuel Pump relay. I didnt think that was it so I never tested it. I swapped it out with another one. And it fired right up without problems. Went to napa bought a new one and there ya go. I tested car tromped it, Drove it slow, idles for 10 minutes. So far no no problems. Thanks all
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Wednesday, January 4th, 2012 AT 6:32 PM
Tiny
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Dandy news. Happy to read it's fixed. You might want to pop the cover off the old relay to see why the fuse was blowing.
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Wednesday, January 4th, 2012 AT 11:37 PM
Tiny
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Hello, I the car was running great and now its acting up again:

yesterday when the car died it was idling when I got to N/S train yard. I parked it and left it running. I was inside the building no more than 20 minutes. When I got back to it I noticed it died. I tried to restart it. It didnt start. I rechecked the fuses. Found the pump fuse popped. I changed it. The new fuse popped upon turning the key. I placed another fuse. Car started for 30 seconds then that fuse popped.

Today I removed the relays and replaced the fuse and turn the key and it popped the fuses with the fuel pump relay out.

Any ideas I appreciate any help
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Thursday, January 12th, 2012 AT 3:29 PM
Tiny
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Well, the cars acting up again.

The car has been running great until yesterday. I was at work for 20 minutes getting paperwork. I left the engine idling ( 20 minutes ) when I got back to the car I noticed that the engine died. I tried to restart it but wouldnt start. I checked the fuel pump fuse to find it has blown. I replaced it it popped that fuse the second I turned the key. I replaced another fuse car started for 30 seconds and popped the fuse.I removed the new fuel pump relay I just put on it 8 days ago. Replaced the fuse and it popped the fuse with the relay removed. Not sure to even start looking now.
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Thursday, January 12th, 2012 AT 3:34 PM
Tiny
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You just split the circuit in half and proved the intermittent short is in the first half, between that fuse and relay. The problem is not in the switched side after the relay. When it's acting up, put in the test light in place of the fuse, then move and wiggle things to see what makes the bulb's brightness change. In particular, look for pinched wires under the carpet, running under the door sill plates, and around the rear seat frame. Unplug that module too. I don't know where that fits into the circuit but chances are it runs off the same fuse.
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Thursday, January 12th, 2012 AT 11:30 PM
Tiny
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Problem found :) It was the crank position sensor wire laying on the harmonic balancer. I actually put it in the shop and they found it in 3 hours. I just ran out of time and needed car I know I could have found it but would of taken me a while to find it. So instead of days it took 3 hours
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Wednesday, January 18th, 2012 AT 1:32 PM
Tiny
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I'll believe it when the problem is gone for a week. The crank sensor should be on a totally different circuit fed from the Engine Computer. Normally they aren't even fused because the computer can shut the power supply down to protect it. I'll keep my fingers crossed.
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Wednesday, January 18th, 2012 AT 1:56 PM
Tiny
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I will keep this posted: This may be able to help someone in the future. But there is something funny also. Before the chimes in the car wasnt working when you open the door with the keys in the ignition or leave the lights on after you shut the car off. The bells are working now. They never have since I had the car. But so far so good :)
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Wednesday, January 18th, 2012 AT 2:08 PM
Tiny
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Here is a update: The mechanic that worked on the car is no longer working there. The wire ( Cranshaft Position Sensor Wire ) that he said was rubbing on the harmonic balancer was not the problem ( Because he didnt fix it as he stated ) 3 days and 10 miles later the car acted up again same problem. The shop that had the car looked where he said he repaired this looked and said there is no way he fixed what was stated. No fix was made to this. So they put it back in the shop and it was there for 2 weeks and they said they cannot figure it out. So they gave me the car back and gave me the check back that I originally gave them for the original repair.

I decided to remove the pump and put a used pump in to see if there is a change. The used pump didnt work. It hummed at start up and never shut off. I tried starting it and it didnt do anything. So I removed that pump and replaced the original pump and it restarted. Now since I put the original pump in and made sure the wiring harness was on tight everything is running as it should. But now the chimes are working plus the control to the passenger side climate control that is on the door. I have been driving it for over 1 week and so far all is good and havent had a problem so far. I hope its problem solved :)

What we think the mechanic did was just replace the fuse and said he done something else.
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Saturday, February 4th, 2012 AT 3:26 PM

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