[needawheel]

no one is doubting him or calling him a novice... its a tricky 20 yr old fuel system and one little 20 yr old wire can knock the whole thing out. its easy to test power and ground. static pressure tells you virtually nothing in this case. it should not be overlooked.

---------------------
thats the thing, the delco pumps and the name brand pumps use a squarish 4 prong connector which matches the oem....they are plug n play, but they are grossly overpriced.

the chinese pumps, of which there are hundreds of different no-name-fly-by-night 'brands' for the exact same pump, all use a flat 4 prong connector that is not oem. he said he had to rewire, so he used a cheap no-name pump from china, not a name brand pump.

theres no better or more accurate way to describe these parts other than 'china'... amazon, ebay, aliexpress, rock auto, and every part store has copies of the same pump each with a different brand name, each brand name with zero brand recognition. some listings even reference multiple 'brand names' for the same part...
theres literally no way to 'construe' that as 'racism' or whatever...

 

[Rhotpursuit]

no one is doubting him or calling him a novice... its a tricky 20 yr old fuel system and one little 20 yr old wire can knock the whole thing out. its easy to test power and ground. static pressure tells you virtually nothing in this case. it should not be overlooked.

---------------------


the chinese pumps, of which there are hundreds of different no-name-fly-by-night 'brands' for the exact same pump, all use a flat 4 prong connector that is not oem. he said he had to rewire, so he used a cheap no-name pump from china, not a name brand pump.

Then how do you explain why my name brand AC/Delco and Delphi pumps all had the flat connector? Even the one Delphi I just put in had a flat connector. Made overseas...didn't notice...didn't care.

 

[Rhotpursuit]

I found this in a quick site search.
Post 6.

New Fuel Pump Connector

Im replacing the fuel pump in the Blazer. I got the new pump in the tank and now Im lookin at the connections. The new pump i ot has a different connector on the top of it, which is fine because it came with that different connector with the new pump and I just need to swap it over. What my...

www.s10forum.com

This one...post 1.

Bosch 67421 Fuel Pump Connector---Keep it or modifiy?

I’m going to replace a fuel pump on a 2003 Extended Cab S10, 4.3L, so I probed the Forum for recommendations, the most being AC Delco, Delphi, and Bosch. One writer said that Bosch is now AC Delco, so save your money and buy the Bosch. Each of these have complaints, but that is the exception...

www.s10forum.com

 

[needawheel]

maybe your del-phi but not your del-co.
delco includes an oem pigtail in case you are replacing a chinese pump that used the non oem plug and you need to wire it back to oem.

this really is a silly argument.
just check power and ground. check your amperage to the pump... should be 10 ish if i recall...
or dont and throw a crank sensor at it. its cheap and easy enough... well that is as long as it doesnt break in half and fall down into the motor and require fishing out.

 

[Rhotpursuit]

Even when the answer is there....

Done.

 

[needawheel]

the info you linked regarding the delco pump is wrong. the correct delco pump uses a square plug. your 12 post guy linked up the wrong PN in his pic. correct PN is MU1751 ...which has the square plug.

 

[Recklessabandon]

The reality is this is a very easy problem to diagnose, I just can't seem to get a straight answer out of the guy. If you have no power on the pink wire at the ignition coil, then it's clearly not a crank sensor. The crank sensor has nothing to do with the coil power, it only helps provide the coil pulse. Look at the diagram below, the coil power comes from the ECM I fuse under the hood. That fuse is fed from the ignition switch, so it could even be a bad ignition switch. If you would work with me a little bit this would be very easy. NO PARTS CANNON!

 

[Rhotpursuit]

the info you linked regarding the delco pump is wrong. the correct delco pump uses a square plug. your 12 post guy linked up the wrong PN in his pic. correct PN is MU1751 ...which has the square plug.

You mean like this one??

More Information for GM GENUINE MU1751

 

[goes2fast]

The pump that I originally put in was an AC Delco and the wiring issues were I just got some of those heat shrink connectors with solder in them and decided to try them out to wire up the new style connector. The wires got hot enough with the power that the pump pulls that it melted the solder. I re-did it with regular connectors and it worked fine until the pump went out a couple of years later. I was out of town so I didn't want to pay the large bill to have it towed home so I ended up paying the AAA-recommended shop to put another fuel pump in and leave my truck outside unlocked so someone could ruin my dash to steal my $1500 stereo/GPS along with $400 worth of tools, a $200 powered sub and a bunch of personal belongings. I will never make that mistake again.

 

[goes2fast]

You mean like this one??

More Information for GM GENUINE MU1751

That is the one I installed but I have no idea what the shop replaced it with as I was too upset over them letting thieves take everything from inside my truck to think to ask what they put in. They probably would have lied anyway since they swore that they locked my truck.

 

[needawheel]

yep. the pigtail is a square.
the mu1751 i looked at had the oem square plug for plug n play. yours didnt? are you sure you have the same PN??
you are arguing over $200-300 china pumps assembled in mexico... who cares when the $30 china pump assembled in china works? cut a hatch in the bed and replace the $30 china pump 10X... save the oem connectors, use a heat shrink weatherproof butt connector, tape it up with 3m tape, hit it with the 3m scotch kote, stick it in a loom and tape it with the 3m friction/abrasion tape

he dont wanna check power and ground? fine. throw the crank sensor at it... its okay. its not 'wrong' to throw a crank sensor...
but it is wrong to say you ruled out a fuel system problem without even checking power/ground.

 

[oldeerslayer]

You guys can end this fuel pump discussion with a quick shot of starting fluid. If it coughs and at least tries to start the issue is fuel. Camshaft position sensors are an easy part to replace and are the only other ignition component I can think of that would effect fueling. No pulse into PCM = no injector function.

Part 3 -How to Test the Cam Sensor Diagnostic Trouble Codes: P0340, P0341

Page 3 of 3: How to Test the Cam Sensor Diagnostic Trouble Codes: P0340, P0341. Testing Cam Sensor is getting power. Testing Cam Sensor ground. Cam Sensor multimeter test.

troubleshootmyvehicle.com

And as far a China bashing goes, any country that gets all bent out of shape and threatens a war when the #3 person in our government visits an ally deserves bashing. I think because no one has taken out Putin the Chinese figure they can play tough guy, too. Some one needs to tell them to lighten up. We spend trillions on imports from them and instead of a thank you, we get FU.

 

[goes2fast]

yep. the pigtail is a square.
the mu1751 i looked at had the oem square plug for plug n play. yours didnt? are you sure you have the same PN??
you are arguing over $200-300 china pumps assembled in mexico... who cares when the $30 china pump assembled in china works? cut a hatch in the bed and replace the $30 china pump 10X... save the oem connectors, use a heat shrink weatherproof butt connector, tape it up with 3m tape, hit it with the 3m scotch kote, stick it in a loom and tape it with the 3m friction/abrasion tape

he dont wanna check power and ground? fine. throw the crank sensor at it... its okay. its not 'wrong' to throw a crank sensor...
but it is wrong to say you ruled out a fuel system problem without even checking power/ground.

Why would I check power and ground when I have the fuel pressure I should at the fuel rail? My bed is Rhino lined so I'm not cutting a hole in it for fuel pump access and I'm not going to pull the bed just to check power when I have the required fuel pressure and there is no spark coming from the coil. I'm not going to buy any more parts until I test them for function.

Did you even bother to click on that link to that pump part number? If you do be sure to watch the video that shows the difference between genuine AC Delco pumps and your made-in-China junk. Knowing how China treats its people that do not conform to their communist standards and the quality of most of their products I refuse to buy anything they make unless I have no choice and have to have the part to make it run.

 

[oldeerslayer]

One thing I should clarify on the crank sensor relearn. That's fine tuning. It'll start and run ok with a new one if it's the problem. A lot of guys don't bother with doing the relearn. They probably don't notice the 1/2 MPG decrease or the 2/10's slower 1/4 mile time. If it's not done, it'll be close. Just not up to what I would consider your standards, since I have come to think of you as one of the guys who wants his stuff right.

 

[needawheel]

Why would I check power and ground when I have the fuel pressure I should at the fuel rail? My bed is Rhino lined so I'm not cutting a hole in it for fuel pump access and I'm not going to pull the bed just to check power when I have the required fuel pressure and there is no spark coming from the coil. I'm not going to buy any more parts until I test them for function.

Did you even bother to click on that link to that pump part number? If you do be sure to watch the video that shows the difference between genuine AC Delco pumps and your made-in-China junk. Knowing how China treats its people that do not conform to their communist standards and the quality of most of their products I refuse to buy anything they make unless I have no choice and have to have the part to make it run.

you need to check power/ground despite having 'pressure' at the rail for multiple reasons.
its a high pressure electric pump. how much pressure do you even have? theres a minimum spec...
second, just because you have in-spec static pressure doesnt mean it will maintain sufficient pressure while cranking when the entire electrical system is under load...
third, if you have a loose wire/connector you could have an intermittent issue.
you can largely check power/ground under the hood with a jumper wire and a meter:

the delco pump is made in china. the assembly is 'hecho en mexico'
theres plenty of reviews saying delcos were DOA too...


and another rabbit hole someone might need to venture down is as follows...
ive pulled the fuel relay over 20 times. on 3-4 occasions, for reasons i did not investigate, the stock anti-theft/security system went bananas and started blowing the horn after pulling the fuel relay... on one of those 3-4 occasions after blowing the horn/setting off the security system it wouldnt start... i couldnt tell you what caused it, i couldnt tell you jack about how the anti theft or security is set up... i had no reason to look into it because after about 5 mins and a battery disconnect-reconnect it miraculously self-healed... but maybe yours didnt self-heal and the anti-theft/security is killing power to your ignition?

 

[Rhotpursuit]

yep. the pigtail is a square.
the mu1751 i looked at had the oem square plug for plug n play. yours didnt? are you sure you have the same PN??
you are arguing over $200-300 china pumps assembled in mexico... who cares when the $30 china pump assembled in china works? cut a hatch in the bed and replace the $30 china pump 10X... save the oem connectors, use a heat shrink weatherproof butt connector, tape it up with 3m tape, hit it with the 3m scotch kote, stick it in a loom and tape it with the 3m friction/abrasion tape

he dont wanna check power and ground? fine. throw the crank sensor at it... its okay. its not 'wrong' to throw a crank sensor...
but it is wrong to say you ruled out a fuel system problem without even checking power/ground.

Did you read the post in the link that said they changed the plug due to shorting issues??

 

[needawheel]

what are you getting at now? bc theres like 3 possible things you are getting at simultaneously and none of them are really relevant to the fact that he should take 5min to check power/ground, but i will respond anyways:
you want to know what kind of plugs are on new fuel pump?, you want to defend china?, and you think one plug is safer/better than the other?

yeah i read it, was that a reliable source? bc theres plenty of new pumps floating around with the oem square connector... i saw one last week and another one about a year ago. both were delcos, both the PN i noted above: mu1751. ive seen all kinds of stock pictures and crap on websites. the two i physically saw had an oem square plug on top of the housing and came with an oem square pigtail. i do see comical pictures on the internet of a different pump housing with the flat plug attached on top and incompatible oem square pig tail laying next to it... apparently delco outsourced the photographers too??... dont know, dont care. i aint paying $300 for a marketing gimmick...

every fuel PUMP i have seen for my s10 was chinese, no matter where the ASSEMBLY was assembled. from my research the quality is hit/miss for every assembly no matter the price, as-is true for nearly all china parts... so my 2cent is to cut your bed and make the process simple and gamble on ten $30 pumps in lieu of one $300 pump... because the fail rate appears to be similar.

in terms of which plug is better, the oem square plug is better unless you are redoing the whooooooole harness bc you have to use the junk butt connectors to cut the wires and switch to a diff plug... the oem square plug without butt connectors is better in every conceivable way then ANY connector relying on the butt splice, even if you 'bulletproof it' with all the 3m tapes looms and scotch-kotes (which i did)

i hope we can put this to bed now.
USAUSAUSAUSAUSA!

 

[KJF95S-10]

Virtually everything is made in China, oem, aftermarket, it doesn't matter. Even the "made in USA" stuff has at least 30 percent global materials or has virtually NO human assembly in its construction. You can thank the EPA, corporate greed, lazy Americans for this. The government makes it mandatory for manufacturing to leave in order for businesses to survive and tells everyone here we need to be college educated to be anyone. As long as we don't see child slave labor or black clouds of smoke and polluted rivers in our country and can still buy hoards of garbage we don't need for pennies on the dollar, we can go on feeling good about ourselves in the good old USA!

Sorry about the rant.

 

[Joe Cool]

Boy has this thread gone off track. Almost 60 posts and only a handful of suggestions, instead it's more about how "I'm right, you're wrong" and parts country of origin debate than trying to solve a problem. Once we make our suggestion, let's try to trust @goes2fast when he says he checked what was suggested, and if we don't have anything more insightful to add to our original suggestions, we need to step back and see if someone else has some different insight.

Unfortunately I don't really have experience with diagnosing ignition problems other than parts cannon style. I had to replace my crank position sensor a long time ago, but I was having misfire problems, and I paid a shop to change it and perform the relearn.

The only other thought on something simple to check would be what @Rhotpursuit suggested: looking at the battery cables if you hadn't yet. After I replaced my battery last time, when I would try to start my truck it would randomly act like the new battery was disconnected, even though the battery was good and the connections were clean and tight. After some fiddling with connections and cables it would start right up. After a month or so of having to reset the time on my clock I decided to do the big three upgrade with welding cables. I looked over the OEM cables and connections I had replaced and never saw any sign of corrosion so I still don't have a good reason why it gave me trouble, I just know it never happened again. I don't remember if you have already done the big 3 upgrade to your truck, or if you are waiting until the LS swap, but it was definitely a noticeable improvement for my truck as it ran smoother and even the blinker was louder. Sorry I don't have anything else to add.