Fuel pump

The fuel pump will run for a couple of seconds with the key in the run position then it will run constantly while cranking the engine.

your welcome... good luck with everything!

i could not get it start at work then it fired up drove home started several more times jus fine is it loosing tis prime maybe?

Hello again!! we got the fuel pump put in. it took forever to get it started ..but it finally did. Then we were given it water and it just keep drinkin it ...looked at the oil...and it was milky...so we just thought it was a blowen head gasket.. so we started taken it apart got to the intake gasket. and it was blowen ...so we got a little lucky. and thats where we are know.....but i had another question for ya...my gas gauge is stuck on fuel....its just layin there...when its running, when the keys out, on everything its just laying there...

Could be you can rent a fuel pressure gauge from auto zone and see if the pressure is bleeding down.Hook up the gauge start it up and then turn off the engine and watch the gauge and see if the pressure bleeds down if so to what pressure it bleeds down too?Monitor the pressure for 5 mins for dropping.

lower intake gaskets are common on the 4.3's.... glad to hear you got it running finally... as far as the fuel gauge goes, everything is hooked up to the sending unit, and all the ground wires were bolted back up right????

Fuel pressure specs below:

from what said already do you think the pump is ok?

The truck will not turn over if I put gas directly in to the air intake it will start and run fine I can restart it but if leave it off for a couple hours it will not turn over. originally I had a check engine light I put it on the computer and it gave me a code for MAF low I believe so I cleaned the MAF and have not had this code reappear so I’m guessing it’s the fuel pump
Thanks in advance for your help

Hello, I'd check fuel pressure. If you have that spider fuel system, they are noted for problems.

what is the pressure???

Roy

A fue things
if i had limited fuel pressure would it be the fuel pump ? and what equipment would i need to test?
and how do i know if i have the spider fuel system?

i will get back to you later with the specs.

You need a fuel pressure gage. If the pressure is low, the problem is usually on the supply side, pump, line, fuel filter, the pressure regulator may go either way.

According to the parts book, you do have the spider system.

Also what it starts at and what it drops to in 5 mins.

i was also told that because it runs fine after i get it started that the fuel pump is fine and it is more likely
my TPS does this make sence to you ?

The fuel pump relay powers it for a few secs to prime the system once the engine starts up the fuel/oil pressure sending unit takes over the power

I can't rule anything out, with that fuel system, I check fuel pressure first. I don't care if it does run good after you get it started. Maybe others troubleshoot differently?

The day before Christmas Eve my truck started acting very strange after being driven about 40-50 miles -- when in OD it started bucking, and the gas wouldn't work, then it finally stopped and wouldn't start again. We are thinking fuel pump??
there is no noise when the key is turned on (like the whining from the pump) and it won't turn over. We tried starting fluid in the intake and it started for like 10 seconds then died again.
We had it towed to our house and when we got it there noticed that when the brake pedal is depressed brake fluid shoots out of the brake line near the middle of the truck???
(this one we are stumped about) - could they be related, or 2 separate issues?
also, does it sound like the Fuel Pump has truely went out, or could it be a regulator?

If you don't hear the pump, it most likely went bad. Before replacing it, confirm that it is getting power and another item hasn't caused the problem. Let me know if you have questions.

As far as the brakes, my guess is you had a rusty brake line, was pushing really hard on the brake pedal when the car broke down or when it was being placed on the flat bed and the steel line broke. The steel lines are not hard to replace. The worst part is removing them without breaking something else. Then of course, the system will need bled.

Parts for the brakes should be under 20 bucks
Parts for fuel related problem (pump) around 150.

Let me know if you have questions or need help doing the job. I'll try my best to direct you via the net.

Joe

can a fuel pump go bad after just 5 mths.if so will it make the truck jerk and then just die.

Hello, I guess anything is possible. I would not suspect the pump without checking fuel pressure, and that is just a start. I'd also check voltage and ground at the pump, engine cranking. Are there any codes?

no codes i dont have machien to check.i have changed the tank and pump 5mths ago.

When you turn the key on, no crank, can you hear the pump run for a couple seconds? You really need a fuel pressure gage.

yes i do hear it

Engine Performance problem
1995 Chevy Blazer 6 cyl Four Wheel Drive Automatic

so i turn on the truck acc wise and it the fuel pump turns on then shuts off like its supposed to but the second i start it the fuel pump kicks on and stays on need less to say my engine gets flooded what do i have to do to fix this besides getting a new fuel pump ? your timely response would be greatly apprceated. thank you so very much shawn jenkinson

With the engine running the pump should be ON all the time. That is how the system works.
Now if your saying that the engine gets flooded with fuel, that is a different item. You will need to pull the upper intake and see if the fuel pressure regulator or an injector line has sprung a leak.

Yeah, you need to check fuel pressure. Go from there.

In the heat of the day(I live in FL) if I run my ac, my fuel pump will whistle and shut down. If you touch the hood it is HOT! If I run the truck without ac I do not have a problem. Can't figure this one out. Also if the engine is hot, if you spray it down to cool it off it will restart with no problem. I do not know where to start ....

Hello, is the engine overheating? What does the temp gage show? Check the trouble codes, or have them checked. Use a fuel pressure gage and check fuel pressure. If you have that spider fuel system, they are noted for problems.

The temp gauge is reading right at 210 when this happens, I have put a fan clutch on it do.

I guess you would know your average running temp better than I, 210 doesn't sound bad to me. I'd be checking the fuel system, if you think the problem is fuel.

I am in Mexico, have put two new "Chinese fuel pumps in my 93 chevy blazer 4.3 vortec, TBI model. 1st didn't work, 2nd worked sometimes. Bought Carter at PepBoys, didn't work at all. One time I saw pressure at about 55PSI. GM says the AC Delco runs at 61PSI, Napa has a Federal Mobile unit they claim puts out 65PSI. Could my problem be as simple as inferior pumps?

It could be a bad pump, relay, wiring... Is the vehicle running with the one from Pep Boys?

Fuel pressure should be 55 PSI and above V6 3.8 W
if not fuel pump is at fault
when replacing fuel pump closely inspect connector wire as its very common failure and cause to a faulty fuel pump replacement

what about the fuel pressure regulator? i've seen lots of bad 1's!

At the back of the truck where the sending unit plugs into the wiring harness there is a two wire connection to the fuel pump. When you turn the key to the on position should one wire "gray" be powered for a few seconds and the other be constant or no power, or is that wire for the fuel gauge? I am trying to determine wether my fuel pump is good or not.

the other should be a ground. There should be another connection for the fuel level sender. But the wire that turns on for a few seconds, it sounds like the system is working fine.

I'm just trying to find out what voltage should be going to the fuel pump. It has an ECM command to a fuel pump module but all the schematics show 12v going to the module but not what is coming out to the pump. If I give it 12v, the pump runs full blast, it puts out about 50 psi. Any help would be greatly appreciated.

Good morning

The pump needs a battery voltage to run.

I attached a diagram for you. 12 volts is supplied to the control side of the relay to energize the load side. Check for that voltage with key on and cranking.

The load side has battery voltage all the time and is fed from a fusible link. It may be located at the starter solenoid.

Then when the relay energizes, it sends power to the module and then off to the pump.

Verify all powers to the components. I circled the fuses you need to test for power. This is not a visual test, you need to check for power with a test light or voltmeter.

Roy