Fuel pump going?

[pcf_mark]

I have never had this behavior before. I just replaced my intake and carb with Performer and Holley. I did this because the old carb was giving me fits and finally left me stranded.

I now have a clear plastic fuel filter installed. It was running good in the garage and I let it run for 5-10 minutes mokeying with the adjustments. When I went to take it out on the road it fell flat and was acting like it was out of gas. Eventually it just stalled. Multiuple restarts and abuse finally got it back in the garage. I could full throttle it and it would barely pick up rpm. Back in the garage I confirmed fuel in the squirters and the float level was good. However I noticed the fuel filter was completely empty. This seems like the pump is bad or the supply line / tank is plugged.

In my experience the fuel pumps are good or they are bad. Has anyone ever had one act odd like this?

Thanks

 

[Explorer]

Not filling the clear filter is common. You can pressure test the fuel pump and check flow running it into a container. I have had them get weak, and the clogged pickup in fuel tank is a possibility. I would check your throttle linkage to make sure you are getting full travel out of it.

 

[NYLES]

I been down that road.....change ya pump! mine would run great on a full tank of gas would supply fuel via hydraulic pressure then at 1/2 a tank, same problems

 

[Old-Red]

I had a fuel pump go out when I first got my Bronco and was Driving it 700 miles back home. It had been sitting for a while and only started every few months. First 500 miles there were no problems but it was flat roads with no hills or mountains. when I came to the first real grade it started running out of gas, bucking back and forth. I would pull over not turning it off and check under the hood, all seemed fine. I would hop back in and go like normal for a mile or so then again it would run out of gas. This would only occur up hill or while the engines was under load otherwise it ran fine. During one stop on an uphill grade I checked under the hood and noticed the clear fuel filter was all but empty, then after a few seconds it would fill back up and I was good to go for another miles or so. I was able to limp into the next town, purchased a new fuel pump and had a shop install it. The shop said there must have been a tear in the diaphragm and it would only work until the engine needed more fuel, like under a load or going up hill. So with a bad fuel pump it would work but only until the engine exceeded a certain amount of fuel usage. With the new fuel pump installed I have never had another problem, knock on wood.

 

[Explorer]

I have never had this behavior before. I just replaced my intake and carb with Performer and Holley. I did this because the old carb was giving me fits and finally left me stranded.

I now have a clear plastic fuel filter installed. It was running good in the garage and I let it run for 5-10 minutes mokeying with the adjustments. When I went to take it out on the road it fell flat and was acting like it was out of gas. Eventually it just stalled. Multiuple restarts and abuse finally got it back in the garage. I could full throttle it and it would barely pick up rpm. Back in the garage I confirmed fuel in the squirters and the float level was good. However I noticed the fuel filter was completely empty. This seems like the pump is bad or the supply line / tank is plugged.

In my experience the fuel pumps are good or they are bad. Has anyone ever had one act odd like this?

Thanks

This part is what leads me to human error. But pump could very well be bad. I'd check the linkage first, it's free.

 

[Rustytruck]

Check your lines from the tank to the pump and make sure their in good shape and all clamps are tight. If the joint clamps or the lines are cracked you could be sucking in air instead of fuel and causing this issue.

 

[blubuckaroo]

Put your vacuum gauge on the pump suction. That's the best test. All the gauges i've seen have a scale for the pump.

 

[pcf_mark]

Lines look good and linkage is free. Trying it in the driveway it ran fine for a while then sputtered. Sure enough filter is completelty empty...

New pump was $23 lets see what that does.

 

[pcf_mark]

I took the old pump off last night and it looks very recent. I have only had the Bronco a year and the last owner had for 10 years but it sat mostly (less 1K miles in 10 years). My guess is the gas with ethanol ate the diaphram.

When I disconnected the line from the tank no fuel ran out. The engine end of the line may be a bit higher than the fuel tank/level of the fuel but I expected something to run out. On other cars the pump is usually lower than the tank so fuel runs out like crazy.

Anyone confirm or deny this makes sense? If I have a tank obstruction it could act like a fuel pump but that sounds unlikely.

 

[Skiddy]

yeah you should of had some gas come out when you disconnected the line. it still could be the pump, if you can blow air back to the tank and see if you can hear any bubbles you will need to remove the cap. then hook it back up and see if you get any gas then. if you still don't get any then more than likely it is the pump.

 

[Skiddy]

I been down that road.....change ya pump! mine would run great on a full tank of gas would supply fuel via hydraulic pressure then at 1/2 a tank, same problems

next you are going to tell us it was a new pump and you changed it out to an electric pump in a motel parking lot huh;D

 

[ICRaider10]

Ethanol in gas can free up crud from your tank and lines that will catch in your pump. With no gas going through, the pump can overheat or get bound up. I had to change mine out on the side of the road with the same issue. THAT pump fried within 500 miles (it was a crappy Mr. Gasket thing). I'm now running a Carter pump with 2 fuel filters, one before the pump and one before the carb. It seems to have done the trick. If you carry extra filters, you shouldn't be stranded. I carry another pump for good measure.

 

[blubuckaroo]

It's always best to troubleshoot problems rather than just change suspected parts. You can end up chasing your tail. Verify the fuel is getting to the pump by disconnecting the hose from the pump and pressurising the tank a bit with compressed air. You should get a good stream of fuel from the hose. Next check the pump with a vacuum gauge at the suction side you just removed.
Also, look for any additional fuel filters someone may have added. I've seen as many as three on one old Bronco and only the first one in the line was plugged up.

 

[Revelation]

In-line filter under the truck between the tank and the pump? Seen PO's add them.

 

[Chief Master Sergeant]

Did the new pump help? Having the same issue here now. Third mechanical pump in five years and I bet I haven't put but 100 miles on it in the time.

 

[Gas Pig]

the answer might be in the fuel

I know this might not your guy's problem with your mechanical pumps but the way gas is formulated now a days it's horrible on diaphragm pumps. Between the extra additives and ethanol it's ever hard on the all rubber components throughout fuel system.

My painter's is always changing his 70 Corvette's pump all the time if he drive the car or not. He never had a problem until they started putting all the extra crap in the fuel. So it's not just us Bronco guys having issues.%)

 

[Bronco73]

Gas tank vented?

 

[NYLES]

next you are going to tell us it was a new pump and you changed it out to an electric pump in a motel parking lot huh;D

Naw i think you was there!

 

[NYLES]

for you ethanol troubles you all need to start using staybyll marine 2, save you lotsa pump troubles

 

[pcf_mark]

Very sorry I did not close this post out. New Airtex pump did the trick. I agree on the ethanol is wiping them out.