Okay, here's the situation. I have an 85 Brat... it's been a great vehicle.

 

Currently it will only run intermittantly. I suspoected teh fule pump; so I disconnected the line running out of the pump and turned the crank. Nothing happened; so I disconnected and re-connected the the wiring and tried again. This time the pump worked great; so i reconnected the gas line and drove the vehicle for the remainder of the day.

 

The next morning, the vehicle wouldn't start. Again I disconnected the gas line and nothing turned the crank, nothing happened. Thinking that the pump may be going bad, I bought a new one. After replacement, the new pump would not work either. I disconnected and re-connected the wiring several times and finally got the pump to work. Again I drove the vehicle for a day with no problems.

 

The next morning, the vehicle wouldn't start again. this tie i began to focus on the elec system. I bypassed the plug leading to the pump and was able to get the vehicle to start. I again drove if for a day and again it wouldn't start the next morning.

 

Now, i am assuming that it is a problem with the relay or the ignition switch?

 

Any advice you could offer would be greatly appreciated.

 

CAMOBRAT

I had similar issues, and it was a bad spot in the wiring where it comes out of the cab to go down to the pump....

I had similar issues, and it was a bad spot in the wiring where it comes out of the cab to go down to the pump....

 

I've inspected the wiring back about a foot from the plug and can find nothing... Could it be a problem with the relay? If the relay isn't working properly could this result in the pump woking intermittanntly?

 

Very odd?

 

camobrat

I've inspected the wiring back about a foot from the plug and can find nothing... Could it be a problem with the relay? If the relay isn't working properly could this result in the pump woking intermittanntly?

 

Very odd?

 

camobrat

 

Yes indeedy. This sounds very much like a intermittent relay problem. You may be able to tap on it lighly to see if that will make it work or if you can find another like it in the car try swapping them.

 

If you don't have a test light probe to test things like this you should get one. It could have saved you from spending money on needless parts replacement and the probes are cheap to purchase.

whatever you try to do, you should be looking for the source of the problem with the key on, in a "stall" situation.

 

In other words, next time you find that the pump isnt working, instead of turning it off and tweaking things, leave the key on. Then, pinch and massage the wires along the length; wiggle every connector. Knock the relay. Find something that YOU do, that makes the fuel pump cut on. With the key on, as soon as you do something that cuts the fuel pump on, then you know you have found the source of your problem.

Here's the deal... It has never worked unless the engine is running or I am attempting to crank the engine. The pump will not come on when the engine is stalled... it's not supposed to... only when I crank it or it is running.

 

Also I'm not sure which relay belongs to the fuel pump. Any advice on where to look would be greatly appreciated.

 

Thanks.

 

Camobrat

Here's the deal... It has never worked unless the engine is running or I am attempting to crank the engine. The pump will not come on when the engine is stalled... it's not supposed to... only when I crank it or it is running.

 

Also I'm not sure which relay belongs to the fuel pump. Any advice on where to look would be greatly appreciated.

 

Thanks.

 

Camobrat

crap, i didnt think about that, safety kill switch. Rats.

Thanks anyway.

 

Camobrat

If the relay is in the same spot as a DL look for it on a bracket above the ECU.

I'm with McBrat each time you've moved the wires down by the pump its had success. I would start there moving toward the relay checking the wires and connectors along the way. Bret

Okay, last night, I made a light switch indicator so i could tell if the pump was getting electricity. I broke into the line about where the plug would be and attempted to crank the car...YATZEE, I'm getting power. Next I re-connected the pump leaving the light in the line and continued to crank with the gas line loose. Sure enought it was pumping gas onto the ground. I re-connected the gas line and cranked for 10 minutes. By this time the fuel filter was barely rising and my battery was dieing. I'm still not sure why it was taking so long for the gas to get to the carb. I changed batteries and continued to crank. Soon I began to see the light flicker and fade even though the battery was strong. I had to leave it at this point. This am I tried to crank it again, but the light didn't come on at all... no power to the pump. I had not touched anything. The car sat in the same spot overnight.

 

Long story short, I am still suspicious of the relay.

 

Could someone please describe in more detail the location of the fuel pump relay? Is it under the hood or under the dash? There appear to be several relay's in a bank just behind the battery. One to the left (starter) and 3 in a row just above the passenger front tire. I know one of them controls the starter solenoid b/c I can hear it switch on/off when I change batteries. I believe one of these relays is for the fuel pump. I've had my best results when i tap on these just before I attempt to start the vehicle.

 

Any further advise would be appreciated.

 

Thanks.

 

Camobrat

The problem does sound like it is with the relay. I don't know where it is but you should be able to use you test light again to find it. First set it up so you can see the light then just start pulling out suspected relays one at a time and see if the light will still come on. When you find the correct one the light won't turn on.

I re-connected the gas line and cranked for 10 minutes. By this time the fuel filter was barely rising and my battery was dieing. I'm still not sure why it was taking so long for the gas to get to the carb.

 

Sounds like your fuel line or filter is clogged. I would think you should have about the same fuel flow after your filter up near the carb as you do back at the pump itself. check to see if the carb is getting good flow to it.

You may have a bad fuel pump but it may be the voltage to the pump is low also. Instead of draining your battery to do a test you could run power directly to the pump and see if that makes the pump run better. If it doesn't then it sounds like the pump is bad.

I have replaced the fuel pump with a brand new one. I know this is no guarantee; but the new pump is haveing the exact same problems as the old one.... It's probably not the pup.

 

My guess is the relay or the fuel pressure switch.

 

i can't find which relay it is until my repair manual gets here.

 

Camobrat

Did you check that the pump is pumping good fuel flow at the carb? Bret

I would do a simple test of the fuel lines. Take off the line from the pump, and blow the line out with fairly low pressure, compressed air. Do this using the line from the top of the front filter. You could have line blockages, causing the pump to overwork itself, making it get hot and cut off.

My filter has three lines. One in the top and two at the bottom. Which one is gas coming into the filter?

 

Camobrat

I'm having the same problem with my 79 Brat. I have replaced the Pump and the filter. It fire up when I add a little gas into the carb but only for a few seconds. I replaced a few wires that conect into the wiring harness that leads to the fuel pump. I'm not hearing my pump kick on so imconfident it's a power to the pump issue. Where you able to identify which relay is for the fuel pump?