96 Blazer 4x4 2 door fuel pump

I just bought this 96 blazer and knew it would need some work. Little did i know there were as many little gremlins as there are. I have been reading posts in the forum, and have figured out my fuel pump is most likely the cause of all my problems. I decided to not be a tight wad, and got the new Delphi fuel pump ordered, but it has not arrived yet. I need to know if the connectors are different on the new fuel pump, and if i will have to get the wiring harness. if it does have to have a new wiring harness, does it automatically come with the new pump, or do i buy that seperately. Also i have already had the old pump out, and found what may have been a short on the connector so i rewired it right, and figured i would test the pump again, but still have the same problems as before. Are there any tricks to getting the new fuel pump completely installed without damaging it? I only want to have to do it once.

I just bought this 96 blazer and knew it would need some work. Little did i know there were as many little gremlins as there are. I have been reading posts in the forum, and have figured out my fuel pump is most likely the cause of all my problems. I decided to not be a tight wad, and got the new Delphi fuel pump ordered, but it has not arrived yet. I need to know if the connectors are different on the new fuel pump, and if i will have to get the wiring harness. if it does have to have a new wiring harness, does it automatically come with the new pump, or do i buy that seperately. Also i have already had the old pump out, and found what may have been a short on the connector so i rewired it right, and figured i would test the pump again, but still have the same problems as before. Are there any tricks to getting the new fuel pump completely installed without damaging it? I only want to have to do it once.

Good Choice on fuel pump.
But you should have run a pressure test before pulling pump.
Your parts place should ckeck and send the wiring kit if needed.

If needed always solder wiries together and seal with sealer.
WATCH TANK VENT LINES AND FUEL LINE CONNECTORS and wire connectors when installing new pump.
Also replace fuel filter with new pump and recheck filter after running a week or so.

After installing new pump run a pressure test.

4.3 W -V6
The only true test on a fuel pump old or new is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
When you get new pump installed.
Post back fuel pressure readings.
Good luck

I've put 2 Delphi pumps in my '97.

The first one I did 3 years ago was a direct hookup, meaning the connectors on the new pump assembly matched my exisiting harnesses.

The second pump I did last year, had a new connector on it (same part number). The pump box also had a mating new connector in it that I had to splice into the existing truck harness. Instructions on how to splice/color match the wires were also included.

So, I'd guess if you open the box, and see a connector with 12" lead wires on it, you'll have to splice it in.

thanks guys... i did the pressure test after fixing the short on the wiring in the fuel pump and getting it back in just to double check it, and it was def. way to low. 40psi w/o motor running, and 50 while idling. bogged down, and almost stalls when i press the gas. Noticed when i was getting ready to put it back in, it was an airtex fuel pump. If i had seen that to start with, i wouldnt have bothered with all the tests. It needs a delphi in it anyways, and couldnt beat $170.00 for the OEM pump brand new, when crappy 'ol airtex pumps are $230.00 from the parts stores. The new delphi will be here tomorrow, and wont take long to put it in, so i will repost and let everyone know if it solves all my lil gremlin problems. Which i am 99.9% sure it will

thanks guys... i did the pressure test after fixing the short on the wiring in the fuel pump and getting it back in just to double check it, and it was def. way to low. 40psi w/o motor running, and 50 while idling. bogged down, and almost stalls when i press the gas. Noticed when i was getting ready to put it back in, it was an airtex fuel pump. If i had seen that to start with, i wouldnt have bothered with all the tests. It needs a delphi in it anyways, and couldnt beat $170.00 for the OEM pump brand new, when crappy 'ol airtex pumps are $230.00 from the parts stores. The new delphi will be here tomorrow, and wont take long to put it in, so i will repost and let everyone know if it solves all my lil gremlin problems. Which i am 99.9% sure it will

If you bought your pump off ebay I hope you had better luck that I did as I had to pull my pump after 4 or 5 month's and bite the bullet and pay carquest the 300 they wanted. The ebay pump was listed as brand new and wouldn't maintain the 60 psi the 4.3's required 100% of the time. It would get hot and then not start the truck and then the ebay seller refused to answer emails. Good luck on your's as I hope your experience is better than mine.

Glad you manged to fix it :smile: My father owns a 2004 Chevy Blazer 4x4. They drive nice and smooth. Almost like a truck/SUV

i didnt buy it off e-bay, i got it from www.getgmparts.com (http://www.getgmparts.com) . they say that they are brand new, and come straight from delphi, and lucky me, the rep that called me back lives just on the other side of charlotte as me and wound up spilling the beans on where exactly he lives. so if i have any problems with this one, and can't get ahold of him, or anyone with the website, i'll just have to take a quick 30 min drive. but i have got the tank back out, and ready for the new pump, just waiting on the fed-ex truck to get here, which according to the tracking info, should be very soon. wish me luck.

i didnt buy it off e-bay, i got it from www.getgmparts.com (http://www.getgmparts.com) . they say that they are brand new, and come straight from delphi, and lucky me, the rep that called me back lives just on the other side of charlotte as me and wound up spilling the beans on where exactly he lives. so if i have any problems with this one, and can't get ahold of him, or anyone with the website, i'll just have to take a quick 30 min drive. but i have got the tank back out, and ready for the new pump, just waiting on the fed-ex truck to get here, which according to the tracking info, should be very soon. wish me luck.

Other things can lower pressure besides fuel pump.
Be sure to run the full test not just engine running pressure.
Good Luck

got the fuel pump in in about 15 min, and it started right up and ran smooth as could be. just a few more lil things to get back on the motor that werent on there when i bought it, and it will be right as rain. got the parts waiting at the dealership right now, just have to pick them up in the morning. do have one more quick question though. on the 4wd models, is the cooling fan supposed to stay running all the time, or should the fan clutch just kick in when it needs it to run? not even sure if this model has a fan clutch. just wonderin. runs great, and sounds good gettin on it with the fan all the time, but dont want to keep drivin it like that if its not supposed to be.

got the fuel pump in in about 15 min, and it started right up and ran smooth as could be. just a few more lil things to get back on the motor that werent on there when i bought it, and it will be right as rain. got the parts waiting at the dealership right now, just have to pick them up in the morning. do have one more quick question though. on the 4wd models, is the cooling fan supposed to stay running all the time, or should the fan clutch just kick in when it needs it to run? not even sure if this model has a fan clutch. just wonderin. runs great, and sounds good gettin on it with the fan all the time, but dont want to keep drivin it like that if its not supposed to be.
These trucks have manual cooling fans attached to the water pump and what your hearing is normal. The way I always check a clutch fan is give it a quick spin and if you feel a good amount of resistance it's fine, If it spins very freely it needs to be replaced.

man oh man! got the fuel pump on, and motor is runnin fine now, and finally got it legal, and got to test drive it for the first time since i got it, and its one thing after another! replaced the calipers, and rotors today, and brakes were alot less squishy, but still not up to par. ran to the store, and on the way back... my brake booster went out, and almost couldnt stop. legs werent strong enough to press the brake pedal that hard. goin tomorrow to get another booster, and hope it works, and nothing else breaks for.... hhmmm... atleast a few weeks haha. maybe i should judt read through all the posts and replace everything everyone is having problems with. might be easier. oh well... gotta give it some lovin to get a $500 truck runnin right. just wish my income could keep up with my spending.