Buick Riv Fuel Pump Issue


#1

Just wondering if I’m missing something. 89 Riv with north of 450K on it didn’t start with no fuel pressure. Power at test connector so pump was replaced yesterday with Delco and harness inside tank which was toasted. Its my commuter car so took it to work today and worked fine until the afternoon when it stalled at 30 MPH three times. Started right up again and didn’t stall on the interstate. Took it back to shop and all are puzzeled but has to be the wiring as I see it.



Three years ago I went through the same thing with the pump replaced twice until they finally looked at the wiring from the pump and found a bad portion. Worked fine ever since.



I told them just to run a new wire to it tomorrow to rule that out. I originally thought the wire ran under the car but appears it goes from the connector to the trunk, then inside to the dash area etc. so I’m not as convinced now the wire would deteriorate that much. Just wondering if I’m off base this time but right last time. Seems to me if there was enough draw to fry the wire in the tank, it could cause a problem with the rest of it. Whaddaya think?


#2

www.carterfueldelivery.com/fuel pumps It doesn’t matter that your fuel pump isn’t a Carter. The information still applies.

For example, the Carter site instructs to inspect/replace the wiring going to the fuel pump. The shop didn’t do that the first time, did they?


#3

There should be a wire with a connector on the end next to the brake master cylinder that’s plugged into nothing. This is the assembly line fuel system prime connector. Try appling 12 VDC to this connector and see if the fuel pump runs. If it does, there’s nothing wrong with the wiring. But in the control of the fuel system.

Tester


#4

Thanks, It needed a pump but its intermittant now. Saturday I applied the 12V to the test connector and no go, but the test light came on at the connector. Ran great with the new pump for 60 miles but then started stalling again with the new pump just like three years ago.


#5

Since the vehicle has a lot of miles and a history of failed fuel pumps maybe the problem is a burnt set of contact points inside the fuel pump relay.
Mileage, age, and high current draw of a pump can be pretty rough on relays, wire connectors, and everything down the line.

What I’ve seen a number of times is that a lousy connection (burnt set of points for example) will permit a test light or VOM to work fine but will not pass the current needed to operate something like an electric fuel pump.

How about removing the fuel pump relay, pry the cover off, and take a look at the points to see if they may be worth filing smooth?
Just a suggestion; hope it helps.


#6

The next thing to try is get under the vehicle and give the gas tank a couple of good whacks with a rubber mallet and then see if the fuel pump works. I just read an article in Babcox’s publication Tech Shop about the rash of bad fuel pumps that have hit the market. Some manufacturers of fuel pumps admit that they consider a 10% failure rate of their fuel pumps as being acceptable. But the techs that install these fuel pumps that have failures aren’t very happy about these failure rates because they have to warranty their work and the part. One tech installed three fuel pumps in a vehicle before he got one to last.

Tester


#7

Did you replace the fuel pump filter sock? Did they replace the fuel filter? If you don’t know, you can tell by just looking at the fuel filter. A new one will still look bright and shiny. If it’s not, replace it.
The fuel pump relay is by itself, isn’t it (next to the strut tower)? Often, relays will be the same type. If you can find another relay (like a horn relay), swap it with the fuel pump relay; or, otherwise, acquire a replacement relay.
There are several Service Bulletins for your car. You should read them for applicable information. Don’t assume that the repair shop read them.
To keep the fuel pump from, possibly, cavitating, keep the fuel tank level at least 1/4 full; or, have a splash shield attached to the fuel pump…as directed by one of the Service Bulletins.


#8

Thanks all. They just ran a new ground and a new hot wire all the way from the pump to the dash connector. So far so good but I’ll run it around town a few days to make sure. Didn’t realize what a rattle trap it was getting to be till I drove a different car for a few days.

That Carter site was very interesting. Pretty sure they never did a voltage drop test, but did replace the hanger harness, sock filter, etc. There are two relays-one at the fuse box and the main relay under the hood. I swapped the fuse box relay and have a spare pump relay. Thing with intermittants is that it started right up again. Just think the wire and connectors were old enough to cause a voltage drop enough to drop the pump momentarily.

Thanks again.