2004-2007 Cadillac CTS-V General Discussion Discussion, Fuel pump going out? in Cadillac CTS-V Series Forum - 2004 - 2007; Having your car start after being towed home is a good sign that it is the fuel pump. I replaced ...
Having your car start after being towed home is a good sign that it is the fuel pump. I replaced mine in Sept with one from Oreillys because it was the only one in town. It then went out a couple weeks ago. It lost power on the highway for a few seconds, kind of seemed like I left off the gas pedal, then it resumed. About 10 minutes later it died when I stopped at an intersection and never started again. I looked through the different fuel pump threads and decided that the stock one was good enough for my limited mod plans so I bought an AC Delco off of Rock Auto and had it shipped to me. I had a full tank of fuel and it was 0 degrees out so I paid the dealership to replace it with my new pump because I needed it back ASAP.
I never got any codes, and I also checked the fuel pressure OBD PID but I could never get a reading. I have replaced a lot of fuel filters, never seen any positive results, but it is a cheap check prior to ripping into this project. You can hear the pump pretty well when you have your back seat out of the car. There is a harness above the rear axle that I toned out to see which wires power the pump, that way I could power it straight from the battery to verify wiring/relays. Here is a picture of it. I can't remember right off hand if this was where I was measuring the voltage coming from the relay or power the pump.
Yeah, melted through at the electrical connection. What are my options guys? Am I going to have to buy a whole new pump assembly? Is there anything I can use to patch it? I'd rather not have to spend $250+ on a new assembly just to have to rip it apart and swap in my DW pump.
On a side note, I realize this is exactly what happened to the guy in the other thread (albeit to a lesser extent), but he was running a BAP increasing the voltage for over 10k miles. This is a 100% stock fuel system on this car with only 88k miles. Does anyone else think it's a little scary that this could happen to you?
Anyone know where I can source the connector with pigtails? All I've been able to find is the connector itself from Racetronix and I don't want to spend $16 on shipping for an $8 part.
Went ahead and found a used pump assembly on eBay for cheap that I bought. Since I'm replacing the pump anyway, it's not a big deal to me how many miles it has on it. Also sourced the connector, so I should be set on the repair.
Simple as can be. Pulled out the bucket and swapped in the DW200. DW said they thought I might need to modify the mounts, but it was literally a drop in. The only modification I had to do was to dremel out the front of the bucket slightly to clearance the rubber hose off the output of the pump. I only snapped a couple pictures as I was in a time crunch to get it done.
You can see the mounting brackets worked perfectly.
I couldn't get a hose clamp on the opposite side of the hose as there was no room where it went, but it was a SNUG fit, so I'm not worried about it.
The harness was a major PITA to install without dropping the tank or removing the alternator. But I got it done. No pictures of that. I was too dirty and angry getting that sucker installed.
Overall, I'm pleased with it thus far. A couple key cycles to get it primed and it fired right up. No noticeable noise while driving, but the priming is loud enough to hear, unlike my factory pump. I like that.
So I tested my fuel pressure today. 40psi after primed and while idling. Any idea why it would be low? It holds at that pressure. What should I check first? Would it be due to the wiring harness, or the pump, or regulator, or what?
I checked it without the harness to rule that out, no such luck. With harness, 40psi, without 35psi. Double checked my gauge on my jeep, reading 47psi which is normal on it...
I hate to be dense, but I do not understand the significance of with or without the harness in the context of whether the engine is running or not running. As I read the literature the pump (the oem pump actually) was supposed to deliver 55-62psi at the fuel rail with the ignition on, and the engine OFF, which means with the engine idling (as in your post #22) it would presumably deliver lower pressure.