Cadillac Fuel Waste and Starting Issues Need Diagnosis

Had very similar symptoms on a 2007 Cadillac CTS with the gasoline engine. The car performance was severely compromised, rough idle, excessive fuel consumption, and intermittent stalling. The check engine light pointed to fuel delivery issues. The problem turned out to be both the fuel pump electrical connection and a damaged wire harness. The fuel system was actually fine, but the faulty connection caused irregular gasoline delivery to the engine. This kind of issue can mimic a bad fuel pump but costs significantly less to repair. The repair involved cleaning the connector pins and replacing a section of the wire harness. It was a serious issue that needed immediate attention since it could have left me stranded anywhere. The car mechanics found the root cause using diagnostic equipment to trace the electrical signals. Common symptoms that confirm this diagnosis: Engine struggles most when warm, Inconsistent idle, High fuel consumption, Check engine light stays on, Occasional stalling Recommend getting the fuel pump electrical connections checked before replacing the entire pump. Car performance returned to normal after fixing just the wiring.

Thanks for sharing that experience. I recently had nearly identical issues with my VW, including the engine stalling and excessive fuel consumption. Was concerned the fuel system needed a complete overhaul but it turned out being just the wiring harness and connectors too. Quick question, do you remember roughly what the repair cost in your case? And has everything been running smoothly since the fix? My car performance is back to normal but always good to know if anything else popped up later.

After getting the automotive diagnosis done, it cost me 95€ to fix the faulty cable connection at the fuel pump. This was way cheaper than replacing the entire pump unit. The repair shop found the exact same issue you mentioned, just the wiring causing irregular gasoline delivery to the engine. Since fixing that connection six months ago, the car runs perfectly with no fuel system issues at all. No more stalling, rough idle is gone, and fuel consumption returned to normal levels. The check engine light cleared up right after the repair. When pump failure symptoms appear, its definitely worth checking the electrical connections first. Saved a lot of money by finding the actual problem instead of just replacing parts. The auto repair was straightforward once they identified the real issue.

Thanks for the input. Finally took it to a mechanic last week and wanted to share what happened. The fuel injector wiring was indeed the culprit, just like you all suggested. Repair cost came to 120€ total including diagnostics. The car mechanics found corroded connectors affecting the fuel delivery system. No need for a new fuel pump after all. Car runs perfect now, no more stalling, normal fuel consumption, and the check engine light is off. Auto repair took about 2 hours total. Really glad I checked here first instead of letting them replace the entire pump. Definitely learned my lesson about getting a proper diagnosis before agreeing to major repairs. The previous shop wanted to charge 800€ for a full fuel pump replacement without even checking the wiring.