1997 Bonneville Issue(s)

[BobT]

1997 Bonneville

3800 V8 engine

My daughter has been driving this vehicle for about 1-1/2 years. On the way home from a recent trip (about 100 miles round trip) it began to give her fits and the check engine light came on so my wife and daughter took it directly to our usual auto repair shop. It was determined that the fuel pump was not delivering the specified pressure so we replaced the fuel pump and filter.

We had just replaced that pump and fuel filter a year ago this past April and although it was a couple months out of warranty they warranted the pump. Still cost me just short of $400.00 to make the diagnosis and repair which sucked.

Ever since getting it back on Wednesday of last week the car has not been performing right. My daughter has reported two seemingly unrelated problems but I’m not so sure anymore.

Problem #1:

It has been extremely hard starting. I’ve taught my daughter not to crank the engine starter more than about 15 seconds at a time. She was telling me that it takes four to five attempts or more to get the thing started and it doesn’t matter whether it is cold or had just been shut off. I decided to use it for this week back and forth to work and see for myself. This morning when I tried to start it after sitting all night I bet I cranked on that starter for nearly 60 seconds before it finally took off. I don’t like to do that but I wanted to see how long it would take. Once running, it seemed to run fine all the way to my job (20 mile trip).

This is not normally how this vehicle has been working. Something is not right. One thing I will do tonight when I leave work is to listen for that fuel pump when I turn the key on. My experience with GM products including this car has been that I should hear that pump run for a couple seconds as it builds up fuel pressure. If fact, I have taught my daughters to listen for it before trying to start the car. This morning when I turned on the key the radio and interior fan turned on and so I couldn’t hear if the pump ran or not but I did wait for a couple seconds before trying to start it.

Problem #2:

Once last week my daughter called told me the brakes locked up. When I asked her to explain she couldn’t describe it well enough for me to understand. Yesterday she was in town at a local convenience store and called me to report the same problem. I told her not to tough anything because I wanted to experience the issue for myself. When I got to the car I got in and pressed on the brake pedal. It was hard as a rock! I mean it was as if it had been welded in place. I pressed and released the parking brake even though I figured these were unrelated and as expected this didn’t help. Then, while pressing on the brake pedal I turned the engine over to start the car and as it was turning over the pedal slowly depressed toward the floor. It was as if the power assist drum had trapped air and the engine turning over created enough vacuum to evacuate the air inside. Once the car started, everything was working fine again.

Incidentally, I also experienced the hard starting thing while doing this. She had just driven the thing and the engine was still hot so there’s no reason it should have to be cranked that long to get it running.

Any thoughts?

[Jeremy airjer W]

I wonder if you don't have a vacuum line disconnected from the engine. This would explain both scenarios you described above. A leak big enough to cause your symptoms should be easily heard with the engine running. If there are no vacuum leaks the first thing I would do is get a pressure gauge on the fuel rail to see if fuel pressure is holding. It is possible that you got a defective fuel pump.

With the engine off the booster should still hold enough vacuum to give you a couple of power assisted pedal pumps. If this is not happening than maybe the booster is bad and the source of the vacuum leak. Usually you can hear this when the vehicle is running as well.

[BobT]

I will check for vacuum leaks. Could it also be a fuel leak somewhere resulting in lost prime to the injector pump or air being sucked into the fuel system? When it starts it doesn't run rough as though there is air in there though.

[Eric Wettschreck]

I'm thinking a fuel leak of that size would be noticed pretty easily.

I was thinking vacuum also.

My neighbors bonnie also had a hard start thing going on. We replaced the fuel pump and it didn't fix anything. He put a gauge on the fuel rail, again, and we ended up replacing the replaced fuel pump.

[BobT]

I couldn't hear anything that sounded like a vacuum leak. I've got it scheduled to go back to the mechanic tomorrow. Hopefully he finds something simple.

[BoxMN]

Have a 3.1 in Malibu that was doing similar thing. Ended up replacing the fuel pressure regulator, and while it helped, did not solve it completely. I ended up finding the plastic housing/tube going from the PCV (or is it PVC..??..) was cracked. Once I put a new one in ($12 at oriely) it has been starting great ever since. Something to check anyway. Good luck.

[Fishinguy40]

I was gonna say fuel pressure regulator. Not sure if back in 97 they attached the vacuum line to it. If they did and the regulator is leaking you will just dump fuel into the intgake which makes for hard starting.

[JOHNBIGDOG]

Positive crankcase ventilation.

[BobT]

Thanks for the tips. Will certainly keep them in mind.

[BobT]

Update:

The problem turned out to be the fuel pump again. Thankfully, this time they didn't charge me to replace it but will be taking it up with their supplier. I hope it's fixed for good this time.

[Jeremy airjer W]

Do you know what brand they installed?

[BobT]

Not sure about the brand but is it okay to mention the supplier name?

[Jeremy airjer W]

Absolutely. No different than saying Walmart, gander mountain, rapala, or McDonald's.

[Whoaru99]

So far I have found that there are some places where paying more (like for the parts from OEM) is worth it. Fuel pumps, starters, alternators, and blower motors to name a few.

Of course it's not always the case but all those original parts lasted a long time on my vehicles. The aftermarket parts don't seem to last near as long in my experience. Oh, sure, the retailer or supplier may warranty those parts but you (the buyer) usually eat the labor and the point is not to have to fix it again for a long time.

[BobT]

I believe they obtained the pump through NAPA auto parts. Personally, I think if it goes out again, I'll suggest they get the replacement from GM.

[Jeremy airjer W]

Then they should have the option of getting an ac delco or a Delphi. Both are offered through napa. I suspect they installed a carter. Not the most reliable pumps.

[BobT]

Now that you mention the brand names, I think they mentioned AC Delco and they were surprised about the problems we have had with these two because they are usually pretty good. I could be wrong though.

[NIBOWMAN]

Try not to use the NAPA/Carter pump on a GM vehicle. For some reason they do not seem to be compatable. I always recomend the Delpi which is OEM.