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Discussion Starter · #1 ·
Replaced brake line and gas lines a while back.

Now the fuel pump is acting up and I thought is was starting to fail but did not do it at the time due to cost.
I was not too bad and just hesitated at idle a little. Now hesitate upon acceleration periodically.

Things I checked.

1. Bad Gas. Replaced. No change.
2. Fuel Filter Change. No Change. Sometime after fuel line replacement you may have a contaminated filter.
3.Tested pressure 40 psi and jumpy, not stable - should be 50 psi.
4. Tested regulator. First no fuel leakage and pulled off vacumn hose while checking pressure and jumped 10 psi as it should.
5. Relay works since I can hear it and starts easily but now hesitation and flashing engine light on acceleration sometimes which means misfire, fuel starved and pull over right away. The error codes are there.
6. Once in a long while wont start and have to punch the tank with my fist. Old trick.


This is alot of garbage out there so I want OEM. Do I have the correct numbers below. I spent hours online trying to decipher this.


From Dealer using VIN on line 1GNFK16Z83J327655

Fuel Pump - GM (19331260)

Fuel Pump Tank Seal - GM (25167743) extra

Fuel Filter - GM (25164003) extra

Sending Unit - GM (19416872) extra


On Rock Auto

GM GENUINE MU1738 which refers to 19331260 and appears to have the sending unit.

1. GM GENUINE MU1738 {#19180099, 19331260, 19369909} Info
GAS; Exc. Robust Fuel System Sender (K53)

or This may be gas , not flex

2. ACDELCO MU2295 {Click Info Button for Alternate/OEM Part Numbers} Gold; Includes Sender Info
One of our most popular parts

Engine VIN Z Alternate/OEM Part Number(s): 10355740, 15049579, 15205628, 19337979, 88966963, MU1050, MU1379
 

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Discussion Starter · #2 ·
Replaced brake line and gas lines a while back.

Now the fuel pump is acting up and I thought is was starting to fail but did not do it at the time due to cost.
I was not too bad and just hesitated at idle a little. Now hesitate upon acceleration periodically.

Things I checked.

1. Bad Gas. Replaced. No change.
2. Fuel Filter Change. No Change. Sometime after fuel line replacement you may have a contaminated filter.
3.Tested pressure 40 psi and jumpy, not stable - should be 50 psi.
4. Tested regulator. First no fuel leakage and pulled off vacumn hose while checking pressure and jumped 10 psi as it should.
5. Relay works since I can hear it and starts easily but now hesitation and flashing engine light on acceleration sometimes which means misfire, fuel starved and pull over right away. The error codes are there.
6. Once in a long while wont start and have to punch the tank with my fist. Old trick.


This is alot of garbage out there so I want OEM. Do I have the correct numbers below. I spent hours online trying to decipher this.


From Dealer using VIN on line 1GNFK16Z83J327655

Fuel Pump - GM (19331260)

Fuel Pump Tank Seal - GM (25167743) extra

Fuel Filter - GM (25164003) extra

Sending Unit - GM (19416872) extra


On Rock Auto

GM GENUINE MU1738 which refers to 19331260 and appears to have the sending unit.

1. GM GENUINE MU1738 {#19180099, 19331260, 19369909} Info
GAS; Exc. Robust Fuel System Sender (K53)

or This may be gas , not flex

2. ACDELCO MU2295 {Click Info Button for Alternate/OEM Part Numbers} Gold; Includes Sender Info
One of our most popular parts

Engine VIN Z Alternate/OEM Part Number(s): 10355740, 15049579, 15205628, 19337979, 88966963, MU1050, MU1379
I went to A1 Auto in the end buying a Delphi. Expensive but also a OEM supplier. It includes the strainer, sending unit and seal. I already have a new metal ring for top. Some GM dealers either don't have it or are a hard to get a hold of to confirm part. Part supplies are hard nowadays due to the bottlenecks. This also has a lifetime warranty.
 

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Discussion Starter · #3 ·
Installed fuel pump. The truck is now drivable and no longer has a flashing engine light causing me to pull over when I accelerate too much.

Found out return fuel systems with flex have spec. presssure that is about 42-52 which is lower than return less fuel line systems.
There is still some slight sluggishness but looking into. The new pump has 45 psi rather then 40 but very stable reading.

Going to just drive it and see how it goes over a week.

No fun changing that fuel pump. Any suggestions would be good as to why still some unstableness in vehicle.

I did notice the outer casing of the e85 module near the fuel filter was partially broke off when I did the fuel lines. Rock must of hit it.
 

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2001 Suburban 5.3L, 296k miles
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I may be due for the third fuel pump change on my 2001 Suburban close to 295k miles.
My second AC Delco pump is now running at 50 psi but no hesitation or stumbling. It used to be 55 psi new.

As far as sluggishness, unstableness, could you elaborate more?
Can you monitor the fuel trims and see what's going on in the fueling area?
Also look at the MAF readings, as A/F ratio will be out of whack.
 

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the throttle position sensor, if its failing can give bad reading that the computer just believes. also if this is a drive by wire system than you have another TPS on the gas pedal itself.

I have old school drive by cable trucks so I have not worked on DBW truck and dont know how to test that out. it is probably done with an obd2 scanner though as that is how you test a regular TPS.
 

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Discussion Starter · #6 ·
I hesitates on acceleration and at a little at idle. It did pop up the flashing engine light but not much. Definitely more drivable and don't have to pull over as much. Also there is an error that popped up on the way to work (40 miles) and the only one. P0304 Cylinder 4 misfire 1 of 1. No other errors
 

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2001 Suburban 5.3L, 296k miles
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My ignition coils and spark plug wires are still original but I'm on second set on the plugs at 295k miles. I had a P0305 misfire and it idled rough also and hesitated on accel. Turned out to be a stuck closed injector. It got stuck after sitting for a few weeks.
I got it unstuck by shocking the #5 injector using a 9V battery.

Using a infrared thermometer on the exhaust #5 confirmed a cold cylinder, no combustion. I changed #5 plug, no change. I swapped coils, no change. So it was the injector.
 
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Discussion Starter · #9 ·
Thanks for the feedback. Will check out. It could also be loose since when I did the fuel lines was all over the hood trying to remove the two gas lines. Thanks again.
 

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Discussion Starter · #10 ·
Well the misfire was on cylinder four per my diagnostics code P0304

1. Checked wires.
2. Swapped a good coil on cylinder 6 for cylinder 4 - no change,
3. Pulled plug and had that reddish brown color and no oil thank goodness.
These were put on with plugs at 99,000 and now about 200,000 miles. To my utter surprise the Delco Plug (PL-246 I think that is the number I read) plug gap was larger than 0.046 or 1.5 times.
4. Regapped, since will replace wires and plugs anyways and at idle is fine.No roughness. Not road tested yet since late and had a few cars behind me. Never saw a gap that big. Do you use the iridium or the platinum's. I hear GM recommends iridium's now. WILL KEEPYOU POSTED.
 

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I understood that iridium's superceded platniums and I have had iridium's in my 97 5.7 k1500 burb for about 10 years now. maybe I should look at replacing them with new ones. my truck is running great though.

When I originally put them in along with a complete tune up I got the mileage up to almost 18 MPG from 14 MPG. I have no idea what's in my sierra but they were relatively new when I got that truck off my buddy.

When I went to buy the tune up parts a very knowledgeable parts guy set me up with them. otherwise I would have went with what the truck originally came with.

So I'm not sure how the iridium's actually compare to platinum but I had a very good experience with running the Acdelco professional iridium spark plugs.
 

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2001 Suburban 5.3L, 296k miles
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No Iridium's or Platinum's for me on my 2001. I put a copper core Delco plugs. Runs fine. I just drove round trip to Atlanta about 400 miles. Got an avg of 18 mpg.
Ran really nice and smooth. I will keep it.

I bought a Sprinter camper van with a 3.0L turbo diesel lately and love it. It gets 24 mpg. (My 2018 gets 11-12 mpg pulling a 5k lb trailer.)
I have no use for my 2018 Z71 suburban and will sell it soon. It only has 50k miles.
No more towing a camper trailer for me.
 

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2001 Suburban 5.3L, 296k miles
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I have $5 and I'll mow your yard for a year? 😃
You sound like my son ! Haha.
I'm thinking about my two grandsons with him so he may get lucky.

Sorry, wdc1 for the out of topic.
 

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Discussion Starter · #16 ·
Love it. Mow the lawn for a year.
Changed plugs and wires. Stuck with what manual suggests for plugs which are the platinum ones. All ACDelco. Nice thing about the wires is they are all the same length. Also put dielectric grease on boot so if I need to remove in future I can. Boots were cemented in and just yanked them out since replacing anyways. Go slow on removing plugs so as to not have them break at the thread. Runs very good so far. All old plugs had that normal reddish brown with some white tint. Nothing wet like oil.
 
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