1995 T/A, L96 (gen4 6.0 iron block)
LPE converter
LS3 intake, billet rails
Aeromotive FPR
stock lines
Walbro 450, hardwired

The fuel pump only primes intermittently (trend: on the first attempt after a few hours). I replaced the pump with a new 450. Primed up and idled for about 3 minutes and died. Would not prime again.

I read that fuse #5 in the kick panel on the dash was related to the fuel pump (owner's manual) checked it and it was blown. Replaced it still will not prime.

I am going to replace the fuel pump relay by the clutch pedal on the floor tonight.

Anyone else have any ideas?

For what it is worth, I have noticed a clicking sound from the front of the vehicle after about 2 seconds after the key is switched to the on position if the pump does not prime. No clue what that is about..

 

Replaced fuel pump relay. Still will not prime.

 

Could this be VATS related? Ive noticed the SECURITY light on. But does it light up anyway?

 

With VATS the engine will start and run about 3 seconds then shut off.

 

Does anyone know what are some methods to disable VATS?

 

The gray/power wire was melted to the ground. Also seems to be loose in the plastic clip. Does anyone know how to remove it?

 

The yellow bulkhead connector on the fuel modules earlier than 1999-2002 can't handle the amps on larger than stock pumps. Even the stock 1999-2002 Delphi bulkhead connector isn't up to the task. To fix it Delphi has upgraded the 1999-2002 bulkhead connector. Racetronix supplies the upgrade with all of their kits, or you can buy it as a single.

In addition the stock wire harness can't handle the additional voltage/amps either and is why an upgraded harness from the pump to the alternator is a requirement when upgrading to a larger pump. The harness wire is 10 guage.

Racetronix points this out on their site and it has been discussed on this forum as well.

Notice the difference in size for the two largest terminal pins that can handle up to 30 amps on the white connector vs the smaller four terminal pins that can handle only 14 amps on the yellow connector. For comparison the first link is the upgraded bulkhead connector (1999-2002). The second link shows the pin size on the yellow bulkhead connector (1998 and earlier).

https://www.racetronix.biz/product.asp?ic=rcs-027

https://www.racetronix.biz/product.asp?ic=bca-4w

Just one of the four terminal small pins on the atmosphere and vapor fuel side of the yellow connector connects to and powers the pump, The maximum amps it can handle is 14 amps. Two of the four pins are for the sender, the third is for the ground.

So this leaves the 98 owners without a suitable bulkhead connector when upgrading to larger than stock fuel pumps? Some on this forum drill a hole for a ground and power and run 12 gauge wires to the pump using just the yellow plug for the two purple sender wires. Or just remove it completely and run all four wires thru the 10mm bulkhead connector hole. It will have to be sealed to prevent vapor loss or worse fuel in a rollover.

FYI:

Racetronix uses two of the four pins on the yellow connector for their dual 450 pump kit (98 only - it's not a issue on the 1999-2002 models with the upgraded connector). Each terminal on the yellow connector handles up to 14 amps which is adequate for each 255 pump. Each pump has it own relayed wire harness from pump to the alternator. A grounding post is drilled in the hat of the sender for the two pumps. The two ground wires from the two pumps are spliced into a single ground wire and it is attached to the vapor side of the grounding post. On the atmosphere side of the post the ground is inserted into a short harness that runs down to the relays.

So is the wiring option below a possibility? I'm not an electrical engineer.

Can you run the power from a 12 gauge wire to the two pins on the atmosphere side of the connector and then from the vapor side of the connector run two 12 gauge wires from same two pins spliced into one wire to the singe 450 pump?

Or is there too much resistance from the spliced wire - one wire into two wires on the atmosphere side and two wires sliced into one on the vapor side attaching to the pump?

I can't tell exactly from their pics, but it appears this is what Racetronix does on their modified in tank harness's they build for the L98 models and some early Corvettes where they state that these harness's will support 450 pumps. The harness uses the same yellow connector shown in pic in the link above.

You will have to replace the yellow connector. I wouldn't trust it's path inside the connector since it has been overheated. Racetronix is a good source. See link.

This is what your harness probably looks like. Mine is a 98. I suspect yours looks the same. The grey wire is power. Racetronix supplies a plug end for it so you can splice your existing harness into the plug and plug it in directly into the yellow connector.




The new connector plug is hard to install. Use a correct sized socket to press the retaining metal clip onto the vapor side until it is tight. Might want to get two, as I bent the crap out of the metal retaining clip on my first attempt. Using a socket allows you to tap it on without bending it.

As you can see. The same yellow connector is used for two pumps on my dual 450 kit.