1989 C4 Corvette Fuel Pump Replacement

[@CrawdaddyCustoms]

The module is a Delphi HP10031. It also lists as DHP10031

[@Ice-Blade]

from where did you get it?

[@garageassembled4701]

You have a awesome kid! I’m always proud to clean up the mess after those type of projects. I know you are too!

[@soniablades7031]

WOW, this is actually easier than changing out the fuel pump on a 01 Accord!

[@Flying_fisher]

Easiest GM fuel pump change in history haha

[@CrawdaddyCustoms]

TRUTH!! 😎😁

[@Smooth05680]

🔥🔥🔥 good video very helpful

[@CrawdaddyCustoms]

Thank you! I appreciate the comments and feedback.

[@felipesandoval7209]

Thanks video definitely helped I have an 89 cranks but no start , would you happen to have the part number for the fuel pump assembly ?

[@CrawdaddyCustoms]

Delphi HP10031

[@almirdelanovic7421]

What is the part number for that fuel pump? I can't find all in one. Most places sell the sending unit and the pump separate. Thank.

[@CrawdaddyCustoms]

I’m so sorry- I answered your question when you asked it, but today I notice it never posted… The module is a Delphi HP10031. It also lists as DHP10031

[@chrisshaffer4040]

How did you know other than maybe testing the pressure that the pump was the problem I have an 89 and it runs for a minute then stalls out I'm being told to replace the pump and the filter but if that isn't the problem then I'm wasting money

[@CrawdaddyCustoms]

Huh, I answered this before, but my message didn’t post. I did do testing to determine it. You can look online for copies of the factory diagnostic procedures, if you don’t have a service manual.

[@mrdeanv4414]

Thank you for a great video and very informative 👍🏻 Amazing...! I have a 95 C4 with 95,000 miles and the engine makes a popping sound when the motor is in full Throttle... like it's not getting enough fuel... so I changed the original Fuel Filter and the Electric Fuel Pump and it still does it... the new electric fuel pump is a (Percision Fuel Pump Kit)....Any ideas?

[@CrawdaddyCustoms]

I used a Precision pump from O’Reilly and had problems. I replaced it w/ a Delco fuel module… problem solved. The Precision unit was defective right out of the box. Maybe yours might be?

[@mrdeanv4414]

@@CrawdaddyCustoms Thank you very much 😊

[@mrdeanv4414]

@@CrawdaddyCustoms It was definitely the Fuel Pressure Regulator... got a new one it's on and starts perfect every time on the first crank.... Thank you so much for your time and knowledge..👍🏻

[@rose2525bud]

🤩👍🏼

[@CrawdaddyCustoms]

Thank you, Terri!

[@Mark69Z28]

GREAT VIDEO.....I HAVE LONG CRANKING HARD STARTING......ONLY 30 TO 36 WHEN PRIMING PSI....GOTTA BE THE FUCKIN FUEL PUMP NO? CAR RUNS GREAT ONCE ITS STARTED,,,,,,GOTTA SQUIRT CARB CLEANER IN PVC TO GET HER RUNNING....THANK YOU

[@CrawdaddyCustoms]

You’ll need to either get a factory service manual or find a digital scan of it- I found them on the various Corvette forums- for proper diagnosis. Basically, you would take a pressure reading at prime, then observe and see if the pressure holds. Then gently pinch off the return line at the back of the car(where you install the fuel pump module) and see if the pressure holds/goes up. Then prime the rail and gently pinch the Supply fuel line and see if the pressure holds/goes up. If this last test shows improvement, your pump or the internal check valve are the likely suspects… however, you could have a leaky injector that’s causing some problems. If your injector was leaking, the fuel pressure wouldn’t hold/would be low. You have to go through and test stuff to see where the problem is… or just trust your judgement and replace the fuel pump. I used a Delco module the second time- testing showed the brand new O’Reilly piece was a POS right out of the box… that’s why you gotta do the testing. Good luck to you! Bright note: These are the easiest cars to service a fuel module on!

[@ah4800]

Those hose clamps are factory every car ive seen is the exact same.

[@CrawdaddyCustoms]

No, those are worm gear clamps. They are aftermarket. They are not rated for fuel injection. OEM EFI clamps are a one time use crimp connector. Aftermarket EFI hose clamps have a thick, smooth band that is tightened via a heavy duty screw. Worm clamps tear the rubber, and can’t hold the pressure of EFI.

[@ah4800]

@@CrawdaddyCustoms every video I've seen on youtube has the exact same setup. 2 on the supply 1 on the return and a pinch style on the vent. If thats not factory then the odds of every single 1 being exactly the same is crazy.

[@CrawdaddyCustoms]

@@ah4800 The first random video I pulled up My Corvette Life. Video called How To Replace C4 Corvette Fuel Pump. 2:05- He says exactly what I wrote about the wrong clamps- someone worked on the car before. I’m guessing there may have been a field service procedure of installing 2 worm gear clamps to replace the factory crimp clamp. These cars are ~35 years old. Odds of them having a replacement pump in them is very high, which would account for the worm gear clamps.

[@windward2818]

@@CrawdaddyCustoms PYI makes an all SS hose clamp that has a non perforated worm drive and rolled edges. I will be putting these on my 89 Vette after I can test my new fuel pump assemble (HP10031) on the road. I have old style worm hose clamps now and they seem to hold the pressure. The challenge with the larger EFI clamps is the rubber insert is designed to lie flat on the hose connections. So you want to minimize how far the clamp hardware sticks up above the hose. In talking with some of my car builder friends, the opinion is that only one clamp should be needed on either the fuel feed or return given the fittings have a bead. Our guess is the reason for the factory using the two clamps on the feed was a way to identify the feed line given that both the feed and return hose size are the same and run in the same direction to the right. The left routed hose is for EVAP. The HP10013 does not have the pulsator on the output of the pump like the original factory design. Instead there is a piece of hose. I purchased a pulsator to see how it would mount to the pump and I was not impressed by how it seals. So I decided not to install. I was more concerned with the pulsator leaking than providing a benefit. If I experience any fueling problems I will consider adding the pulsator. The HP10031 fuel level sender is improved over the original factory design by having dual wiping surfaces (as opposed to the factory coiled wire single wiper) with one dedicated to ground, and is made of plastic. The ground connection for the factory unit is provided by a spring, which if it gets corroded, will go open. I think the new sender design float provides a needed side load on the wiper arms when immersed in gas. I also think the resolution is not as fine as factory, but the dash circuitry has a strong input filter on this signal. So the HP10031 sender should operate like the original factory sender. The output resistance range of the new and old sender are the same, and I did a measured tank level test and the sender geometry seems to be correct.