I need some diagnostic help from all you Bonneville owners who have experienced fuel problems. The car does not start! Here's what I have done. After the car died, I checked the fuel regulator for pressure after finding that I had plenty of blue spark. The regulator has an air conditioning style fitting and I hooked up my AC gauges and ran a hose to a coffee can. No Fuel. I listened for the pump sound with my Stethoscope and zero noise. I replaced the fuel pump relay and still no fuel. Last night, I dropped the tank and replaced the fuel pump. Added 12 gallons of gas and still no fuel. When I crank the engine, I get RPM's and oil pressure. I know the oil pressure system is tied to the pump circuit. I now am leaning to replace the ECM! I love solving my own auto problems and haven't been to a dealer in many years.

HELP PLEASE!:mad::banghead:

This may sound silly, but what about your fuel filter? And, have you set off any codes? I dont have a service manual that will cover your year car, but I'm sure someone can jump in here and tell you what circuit to check that operates your fuel relay.

I forgot to tell you, I did change the fuel filter. The pump is just not running. I disconnected the fuel filter line turned the key and not a drop. Thanks for the reply. I'm going to go to Helm's web site and order the factory manuals. Probably $$$$ well spent. I have a 93 Grand Prix manual set from a former car and it outlines the circuit very well. I just need to see the 98 Bonny version. Thanks Again!

This may sound silly, but what about your fuel filter? And, have you set off any codes? I dont have a service manual that will cover your year car, but I'm sure someone can jump in here and tell you what circuit to check that operates your fuel relay.

Just did my 99 yesterday. I also out a new relay in. There is also a fuse for the fuel pump. On my 99, the fuse and relay were under the glove box. I had to take off a large piece of plastic, to get to it. It turns out my filter was totally plugged, which probably burned out the pump. I tested the old pump before I went to buy another. Test your old pump, and at least you will know it was the pump. If it was bad, I would say either the new pump is bad, (unlikely) or the electrical connection is bad.
The first thing I did, was to turn the key on, and could hear the new pump running. I took the gas cap off and put my ear to the filler neck. I noticed when I was taking the tank off, that the electrical into the fuel pump, seemed hard to come off. I cut the wires and spliced them back. After pulling the tank out and getting a better look at it, I could see no way to get it off. Cutting the wire was the right way. Bottom line, I would make sure That pump is running. Mine fired right up with the first crank. Good luck!

Thanks for help, I should have checked the new pump before I put it in. I can pull the tank out but I would prefer not to go through all the work. I orderd the Helm shop manuals today and will now have the circuit diagrams and trouble shooting tips. I will check the old pump for operation and if it does run, I was barking up the wrong tree. I will post my findings when I solve this problem. Thanks Again.

Just did my 99 yesterday. I also out a new relay in. There is also a fuse for the fuel pump. On my 99, the fuse and relay were under the glove box. I had to take off a large piece of plastic, to get to it. It turns out my filter was totally plugged, which probably burned out the pump. I tested the old pump before I went to buy another. Test your old pump, and at least you will know it was the pump. If it was bad, I would say either the new pump is bad, (unlikely) or the electrical connection is bad.
The first thing I did, was to turn the key on, and could hear the new pump running. I took the gas cap off and put my ear to the filler neck. I noticed when I was taking the tank off, that the electrical into the fuel pump, seemed hard to come off. I cut the wires and spliced them back. After pulling the tank out and getting a better look at it, I could see no way to get it off. Cutting the wire was the right way. Bottom line, I would make sure That pump is running. Mine fired right up with the first crank. Good luck!

Just listen in the tank, the fuel pump will make a distintive noise.

if the fuse is good and the relay is good and clicks when the key is turned take a rubber hammer and beat on the fuel tank while someone cranks it sometimes the vibrations are enough to get a stuck pump running again. you'll still have to change the pump unless you want to brake down somewhere. good luck with this

I was on vacation and ordered the factory shop manual and followed the procedure for checking the fuel system. When I jumpered the fuel pump relay and turned the key. The pump runs! The relay works when energized but is not receiving the signal to run the pump for the two seconds. I own an "Auto Tap" computer scanner and when I connect it to the OBD terminal, the laptop does not recognize the vehicle.

Tomorrow, I will replace the onboard Engine Control Module! More to follow. I love my Bonneville!:mad:

if the fuse is good and the relay is good and clicks when the key is turned take a rubber hammer and beat on the fuel tank while someone cranks it sometimes the vibrations are enough to get a stuck pump running again. you'll still have to change the pump unless you want to brake down somewhere. good luck with this

Tomorrow, I will replace the onboard Engine Control Module! More to follow. I love my Bonneville!:mad:


Now to change your PCM you have to have the computer eprom reflashed with the correct cal! You are going to have to take it ot the dealer to have that done. There are other options instead of going to the dealer but I will leave that up to you.

BTW just so you know your PCM is under factory warranty for 8 years 80 thousand miles, if you are under that then you just wasted your money on a computer.

Why do you fix your car instead of taking it to the shop?

Flatrater,

Thanks for the reply. I believe the Bonneville has less than 80,000 miles on it so I may have spent the $50.00 in vain. As to why I fix my own cars, the answer is three-fold. 1) I love the challenge of trouble shooting the car and solving the problem myself. The factory manual can guide me to the solution in most cases. The second reason is that of trust. I'm sorry to say, I don't trust someone else working on my car. There are plenty of horror stories out there from my friends and co-workers to fill the rest of this forum. My secretary had a water pump replaced at a dealer for $585.00 last week.

Thirdly is to save the money. I don't know what they get to replace an in-tank fuel pump but I know it is not cheep. I normally order the factory (Helms) manual when I purchase a car. It pays for itself the first time I have to make a repair under warranty. I wish I had ordered the Bonneville manual sooner.

Now that you know my reasons, I still need your advise. I know I have to reprogram the E-Proms and you mentioned some alternatives. Will you share them with me? Again, thanks for your reply. My neighbor works for a Chevy dealer and I go to him when I run up against a brick wall. I will see him tonight. Thanks again for your help with the 80,000 miles. I was not aware of that.